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How do we mold our ASTRO ebike?

We are flattered that many of you have complimented us on our choice of components. We too think this is so important in achieving one of the best class 3 ebikes for the money. We combine high quality frames with high quality ebike motor to demonstrate our brand spirit.

However, our pursuit of value does not stop at our choice of components. We tried to achieve more at every stage of the manufacturing process. A particularly important part of that process is molding. Most companies don’t use this kind of customized molding process, it’s a lot of extra work but we believe it is worth it because it adds so much value to the bike. It allows us to create a bike that is not just your standard, run of the mill vehicle. It has a distinctive look which draws your attention instantly.

In this article, will provide an in depth look at the topic of molding, so you can feel confident if you chose to buy our ebike online. We believe that our iterative process of constant improvement in molding has been integral to achieving an end product that many of you have so kindly named one of the best ebikes of 2022. We’re so excited to tell you all about it!


Why does the bike need molding in the first place?

Before we dig deep into the process of molding the ASTRO, we’ll first give you a bit of background by discussing why it needs molding in the first place. It’s an important part of the process, so explaining the fundamentals clearly is necessary.

One of the main reasons is to achieve the look of the design. To create a product that embodies our idiosyncratic design, we must have a very extensive molding process which pays an extreme amount of attention to detail. Our design was very unique and the cost of developing molds was prohibitive for a fledgling e-bike company. We had to get creative and design an original method of molding that satisfied our complex manufacturing needs. Although the types of materials used and steps for molding are the same as those other ebike manufacturers, the brands of materials used, and the timing of each step were specifically tailored for the ASTRO.

Another reason is to cover the basic needs of the rider. The rider needs a bike that is perfectly shaped and polished so that it can be ridden with pride and confidence. Without such an extensive molding process, the biker would not experience such a brilliant riding experience. The end product feels reliable, professional and polished.


What is involved in the molding process and how do we mold it?

The molding process involves using a variety of materials products to smooth and finish the bike frame. One of the components is putty, we use Resin and AB glue as putty, which is used to smooth the bicycle, so perfectly emulates the shape that our design team intended.

At this point, the frame of the bike is already in the desired form, but the frame needs polishing to make sure it looks presentable and aesthetically appealing. We first have to wait for the frame to dry out. Then, once dried, polish is applied to finish the bike. These three material components result in a frame that is ready to use. It takes around 5-6 hours to make 1 frame. This is a fairly long and rigorous process, but it is necessary for such a high-quality end product. We expect some of you may be curious about this topic though, so we’ll explore the topic a bit more below. Why does molding the C3STROM take so much time?!

It takes such a long time to mold the C3STROM because we aim for our product to look flawless. We place a huge emphasis on the quality of our aesthetics, both at the design stage and at the production stage. We believe it is only right for the finished product to fully embody the elegance of the original design. We can only ensure that by paying immense attention to detail. Otherwise, our intensive design process would feel like a waste of potential. To do justice to the immense effort that is expended at the design stage, we make sure the molding stage is also of an outstanding quality.

We also aim to make our frame look like an all-in-one design. We want to avoid having the product look like a hatchet job and not properly finished. It’s incredibly important for the product to look like one coherent, smoothly finished piece of work which feels seamless and natural. We decided right from the beginning that spending a few extra hours on each frames production is simply a no brainer. The return on investment is well worth the extra energy expended to achieve such a satisfying, striking look. Luckily, our customers so far agree – so many have called our bike the best newcomer ebike of 2022 for the look alone!

There is also a very strict quality control process to ensure that the product is of the best standard.  We put an inordinate amount of effort into making sure that each part of the process is sufficiently rigorous. If we cut corners at any stage of the process, the stunning aesthetic of the end product just simply would not be possible. As the style of our bike is one of its key virtues – perhaps the paramount feature that distinguishes it from our competition – this process has been honed to perfection.

While we are big believers in efficiency, this cannot come at the expense of quality. We have assessed each part of the process and concluded that no aspect can be discarded without significantly affecting the quality of the end product.


It’s all in the molding

We realize it can seem a bit mysterious from the outside why certain parts of the manufacturing process are given so much time and attention. We hope from this article you are more informed now about the molding process and why it’s so important. It certainly plays no small part in arriving at the end product. The one thing we hope you take away from this article is that it’s all in the molding.



CHAPTER 1 How Does an Electric Bike Work?

What exactly is an Electric Bike?

How do Electric Bikes Work?

What does W&Ah mean?


CHAPTER 2 Different Types of Electric Bikes

What are the various types of E-Bikes?

What are the various classes of E-Bikes?

Where is the motor on an E-Bike?

Where is the battery on an E-Bike?


CHAPTER 3 Where Will You Be Riding?

Using an Electric Bike to Commute

Electric Bike Regulations


CHAPTER 4 Pedal Assist or Throttle Controls?

What’s the Difference Between a Pedal Assist Electric Bike and a Throttle Electric Bike?

How Does an Electric Bike Throttle Work?

Why Choose a Throttle?

Do All Electric Bikes Have a Throttle?

Speed sensor VS Torque sensor?


CHAPTER 5 How Far Will You Be Riding?

Electric Bike Battery Types

How long does the battery last on a single charge?

How Much Does an Electric Bike Battery Weigh?

What Is the Longest Range Electric Bike?

How to calculate the charging time?


CHAPTER 6 Safety

E-bike Battery Tips

E-bike maintenance

Why need a derailleur set while it is an electric bike?


CHAPTER 1 How Does an Electric Bike Work?

What Is an Electric Bike?

The first thing that comes to mind when thinking about electric bikes is scooters or motorcycles. Still, in terms of shape, it is not much different from a regular bicycle, with the addition of some electrical parts (motors, batteries, controllers, meters, etc.) to a bike to turn it into an electric bike.

How Do Electric Bikes Work?

The controller employs the pedal-assist system or the throttle signal to enable the motor to convert the electric energy stored in the battery into kinetic energy, which is then used to drive the wheelset to rotate via electromagnetic induction.

What does W&Ah mean?

The power of the motor is represented by the W; the larger the W, the greater the power. The capacity of the battery is denoted by the letter Ah.

When compared to a transportation horse, the weight of our common carriage horses can carry is vastly different from the weight of goods that a Shire horse can carry, but this also means that the Shire horses will consume more feed. This is also true for the motor system. Furthermore, a more powerful motor will consume more power, so a larger W motor power requires a larger capacity battery.


CHAPTER 2 Different Types of Electric Bikes

What Are the Different Types of E-Bikes?

Are you perplexed when you see each brand’s product categories? Depending on the circumstances, the E-bike can be classified into several types. If we divide it by usage scenario, for example, it can be divided into E-city, E-fold, E-cargo, and so on. When it comes to performance, it can be classified as E-road, E-MTB, or E-gravel, among other things.

What Are the Different Classes of E-Bikes?

Class 1 E-bike – Pedal-assisted only electric bike.

Speed limited to 20mph.

Class 2 E-bike – Throttle E-bike with an optional pedal-assist

Speed limited to 20mph

Class 3 E-bike – Pedal-assist & optional throttle.

Speed limited to 28mph.

Class 4 E-bike – Unlimited power & speed electric bikes with pedals.

Any E-bike which has a higher assisted speed of 28mph or power over 750W is considered as a class 4 E-bike.

According to National Conference of State Legislatures: State Electric Bicycle Laws. 

Where Is the Motor on an E-Bike?

Hub motors and mid-drive motors are the two types of electric bicycle motors; the hub motor is usually integrated into the rear or front wheels. The mid-drive motor is located in the middle of the bike, between the bottom bracket pedals.

Where Is the Battery on an E-Bike?

Many factors influence the location of the battery, including the bike model, battery size, and so on. The down tube is the most common location for the battery. The down tube battery not only does not detract from the appearance, but it also maintains a good balance.


CHAPTER 3 Where Will You Be Riding?

Using an Electric Bike to Commute

The use of an E-bike for commuting has become popular in recent years because it not only saves time, but also allows you to exercise while commuting to work, and it is also environmentally friendly.

Electric Bike Regulations

The Consumer Product Safety Commission regulates electric bicycles for product safety reasons. This means that the federal government only regulates the condition of a for-sale electric bicycle, not how it is used. An electric bicycle is defined by federal law as a low-speed electric bicycle with fully operable pedals and an electric motor of fewer than 750 watts that do not exceed 20 mph when powered solely by the motor. The maximum speed for travel using a combination of human power and a motor is not specified by federal law.

You should check with your state to see which E-bike laws apply to you. State traffic laws differ and govern how electric bicycles can be used in each state. W-bikes are defined in most states’ traffic laws, but some do not. Furthermore, some states have laws that only apply to electric bicycles. Some states, for example, require a license to ride an electric bicycle. Other states have laws that apply to electric bicycles in the same way that they do to traditional bicycles.


CHAPTER 4 Pedal Assist or Throttle Controls?

What’s the Difference Between a Pedal Assist Electric Bike and a Throttle Electric Bike?

A pedal-assist e-bike only assists when the pedals are pushed and the motor’s electronic system is engaged. You can select the level of assistance you want with pedal assist. Most bikes have three to five assist levels ranging from low to high. When you start the E-bike, the PA system will automatically turn on, and the pedal assist will kick in as you pedal.

If you want to get a workout, choose a low setting, and you’ll get a little pedal-assistance, requiring you to pedal harder. A high setting, on the other hand, will get you where you need to go faster and with less effort than a low setting.

A throttle e-bike propels the vehicle forward without the need for pedaling.

How Does an Electric Bike Throttle Work?

An electric bicycle’s throttle is very similar to a motorcycle’s throttle. It is typically mounted on the handlebars. For example, when you twist the throttle, the bike will begin to accelerate and will come to a complete stop when you let go of the throttle.

Why Choose a Throttle?

Throttle can be a great addition to your e-bike riding experience. Instead of pedaling, a throttle provides a boost on demand, which can be useful. A throttle gives you more power and control, making biking less exhausting, especially for those who haven’t ridden a bike in a long time. The throttle will be there for you as a good friend, and it’s always nice to have another option.

Do All Electric Bikes Have a Throttle?

Not all electric bicycles on the market, according to laws and regulations, have a pedal-assist system and a throttle. However, as a brand that specializes in the C3 classes, all of our current and future models will include both a pedal-assist system and a throttle, providing our customers with even better experiences.

Speed sensor VS Torque sensor?

A torque sensor detects how hard the rider is pedaling; the harder you pedal, the more assistance; a speed sensor detects how fast the rider is pedaling; the faster you pedal, the more assistance.

Based on your requirements, you can select the best type for you.


CHAPTER 5 How Far Will You Be Riding?

Electric Bike Battery Types

Lead-acid Electric Bike Batteries:

Lead-acid batteries are the most expensive and difficult to recycle, have a lower power output, and are the heaviest type of E-bike battery.

Nickel-cadmium Batteries (NiCd):

Lead-acid batteries have less capacity per pound than nickel-cadmium (NiCd) batteries. Nickel-cadmium, on the other hand, is expensive, and cadmium is a hazardous contaminant that is difficult to recycle.

Nickel-metal Hydride Batteries (NiMh):

Nickel-metal hydride batteries have a short lifespan. Even when used infrequently, NiMh batteries produce a lot of heat and are difficult to keep in good working order.

Lithium-ion Batteries:

Lithium-ion batteries have the highest capacity of any existing battery type. They are not memorable, which makes them more durable and long-lasting.

In conclusion, Lithium-ion batteries seems to be the best option for E-bike.

How long does the battery last on a single charge?

The battery’s lifespan is determined by a variety of factors, including battery power, whether you use pedal-assist or steering, and even road and weather conditions. However, it can typically travel 25 to 70 miles on a single charge.

The battery’s entire life is determined by the type of battery. Lead-acid batteries typically have a charge cycle life of 200 to 300, whereas lithium batteries have a charge cycle life of 500 to 1,000.

How Much Does an Electric Bike Battery Weigh?

The weight of a battery is determined by its size and capacity. A 48V standard battery with 52 cells, for example, weighs slightly more than 7 pounds, whereas a 52V battery with 70 cells weighs 10.6 pounds.

What Is the Longest Range for an Electric Bike?

Our C3STROM-X1 with 52V20Ah 21700 battery cells use throttle only, the most extended range is 32miles.

How to calculate the charging time?

You could use the following formula to calculate the charging time:

Use the battery’s AH and the charger’s A (e.g., 52V20Ah battery with 58.8V4A charger, so 20Ah4Ah=5h, or about 5 hours)

This way, you can get an idea of how long it will take to charge.


CHAPTER 6 Safety

E-bike Battery Tips

  • Charge your brand-new battery pack for 12 hours.
  • Temperature extremes should be avoided.
  • Before charging, turn off the motor and the battery.
  • Don’t let your E-bike battery run down.
  • Avoid overcharging the battery.
  • Even if it is not in use, recharge your battery at least once a month.
  • Do not leave the charger plugged in all the time.

E-bike maintenance

The key to extending the life of your E-bike is to keep it clean and dry, but here’s some simple advice:

  • Before each ride, check your tire pressure.
  • Check and adjust the brakes on a regular basis.
  • Keep the battery completely dry at all times.
  • Clean your E-bike on a regular basis. Find a reputable bike shop and take your E-bike there once a year for inspection.

For more information, please visit our blog at this link:

《Detailed guidance for electric bike maintenance》

Why need a derailleur set while it is an electric bike?

This question is for when you’re riding your E-bike with the Pedal Assistance (PA) system.

An e-bike is a bike that has electronic components to make your ride easier, but it’s still a bike if you don’t use the throttle at all. Adding a derailleur set may allow you to have a better riding experience on different terrains.

What We Learned From Launching Our Ebike Brand On Indiegogo

We are so grateful that our class 3 ebike ‘ASTRO’ has been called ‘the best ebike for the money right now’ by many of our backers on Indiegogo. We have produced one of the best value commuter ebikes by selecting brilliant but affordable technology, such as the BAFANG 750w ebike motor.

Of all the ebike classes, class 3 ebikes were our favourite for their speed. We were so excited when we could finally deliver the goods and got the support of so many people around the world on our first Indiegogo campaign.

We managed to raise an astonishing $500,000 from a whopping 267 backers. This far surpassed our expectations here at C3STROM and we cannot thank our backers enough. Without their support, it would not have been possible for the wider community to buy our ebike online.

Since we launched the campaign, we have learned so many things along the way that we want to share with you, so we decided to write this dedicated article. We’ll be satisfied if you feel even a fraction as excited reading about it as we felt doing it. Enjoy!


So, how did we do it?

We achieved our goal of a successful Indiegogo launch by focusing unwaveringly on the fundamentals of what makes a good product. We knew that ebike riders with an eye for the best ebikes around – our target audience – would be able to tell whether our product was worth the money. That’s why we made sure that at each stage in the design process, we gave the utmost attention to detail and professionalism to create a top-tier class 3 ebike.

All of that started with our planning. The planning stage was critical, of course, so we were meticulous in our search for the best ebike configuration. We tried to always make sure that the people we had in mind would be satisfied – people who loved the finest technology paired with stunning aesthetics.

Our designer loved the motorcycle look, so he got working on a plan for an ebike with this dashing style. We then got started on making the bike by putting it through months of rigorous trial and error testing. After making some modifications to the configuration and the components in order to ensure optimal comfort (e.g., the frame size, the mud flaps, etc), we were confident that the final product would meet the expectations of our customers.

Placing the rider at the centre of our universe was vital for getting where we are now. Not only did we have the rider in mind when we were in the planning and designing stage, but we also had them in mind when we started thinking about customer service.

Having customer service there right from the start of our riders’ ebike journey was a must – we knew that much. But by ‘the start of the journey we weren’t just thinking about after the customer received the product or even about the point of purchase – we wanted customer service available even before that. We had dedicated staff on call even before the customer even clicked ‘buy’ to ensure that any issues or queries were addressed beforehand. Having customers buy our product with peace of mind was a high priority for us.


But why did we do it?

You may be wondering why we even attempted such a feat. After all, a high-end class 3 ebikes are difficult to design and manufacture. It’s also a highly competitive market right now – a senior manager at another brand that we communicated with before we got started told us that it wasn’t a great time to get involved right now given the supply shortages in the global economy and the competition. But we didn’t let this hold us back. We wanted to take an exciting risk with the hopes to become one of the best ebike brands around at some point in the future. After all, every ebike brand must start somewhere. We just loved the process of production and development of ebikes so much to resist the temptation – it’s our passion here at C3STROM. So, we knew it would be a labour of love making the ASTRO – not at all a thankless uphill battle.

We’ll delve further into some of the why questions you might have on your mind about Indiegogo, the ASTRO and the ASTRO PRO here.


Why Indiegogo?

We decided to start out on Indiegogo because we are a new ebike brand. We weren’t entirely sure who exactly our first customers would be. But instead of marketing in the boring, traditional way by simply doing standard market research, we were open to exploring new ways of finding the most passionate biking enthusiasts around. We were looking for a way to connect with those looking for the best ebikes for the money – wherever they might be. A platform like Indiegogo gave us that very option, which was perfect for us.

We also wanted to crowdfund the ASTRO and ASTRO PRO, as this gave us more financial resources to ensure we would create one of the best ebikes of 2022. We wanted to spend our limited internal budget and energy on ensuring the ASTRO stayed close to our original ambitious design concept.  We figured crowdfunding would be a great fit, as the customers willing to back our ebike would also surely be the customers most passionate about the kind of class 3 ebikes that we set out to produce.


Why did we make the ASTRO?

We wanted to create one of the best-looking class 3 ebikes. We placed a lot of emphasis on the aesthetics of our bike, we saw a lot of neglect when it came to looks with other models on the market. There was also a large amount of demand for bold, unique-looking bikes. In our estimation, this demand was simply not being served very well at all. Our designers were passionate about bringing a cutting-edge style to the market that people could get excited about.

Quality was also on our minds. All throughout the design process, great care and attention to detail were paid to designing the bike, so that the finished product was something the rider could be proud of, rather than just an arbitrary collection of components jumbled together.

However, the quality of the components themselves was also high up on our list of priorities. We wanted to make sure that the bike did not rely on any one single gimmick or feature in its spec list. For that reason, we made sure that the components were high quality across the board. The ASTRO performs brilliantly in many different categories because of the consideration we gave when choosing components. Such as: a 750w BAFANG ebike motor and a high-quality Samsung 21700 battery.


Why did we make two editions, the ASTRO and ASTRO PRO?

Once we decided on making a class 3 ebike, we had to think about the components we would use and the price. We wanted to appeal to a broad swath of the ebike market to have a shot at one day becoming one of the best ebike brands around. We wanted to make sure that prospective customers with different wants and needs were not unnecessarily excluded from having a chance at getting their hands on our product and experiencing ebike technology for the first time.

To achieve this, we decided to create two editions both set at different prices. For the more casual rider or someone just starting out with ebikes, who does not want to spend such a huge amount of money, we priced the standard ASTRO at just $1699/$1799. We were sure this would make it one of the best ebikes for the money on the market.

But for the more serious ebike fanatic, who cared a great deal more about the specs of the bike, we created the ASTRO PRO at a higher price tag of $1899/$1999.  At this higher price tag, it had superior features. We figured this was a great solution that would make us all happy.

The choice to have two editions is also about the needs of different users. The regular ASTRO is great for your average rider who wants a versatile bike ready for almost any situation. But the ASTRO PRO is tailored specifically for those who have a much longer commute as it can go much faster.


What’s special about C3STROM?

Of course, other ebike companies may do some of these things we spoke about above. But few do all of them together. There are one or two things that we think make us a little bit special here at C3STROM.

Perhaps the most important is how we deal with our customers. Instead of just sending out generic emails or offering a phone number to call for special issues, we maintain high-frequency communication with our customers through many different channels. Getting to know our customers on a personal level and understanding their issues and requests is very important to us.

We’re aware that often our customers have complex wants and needs, so learning from them one-to-one is high on our list of priorities. We know that the best ebike brands focus on seeing and catering to the individual, not just blindly creating a product for some assumed market.

More fundamentally, we place a high emphasis on making sure the product itself is of outstanding quality. Hundreds of hours of consideration and care went into the design process, to ensure that our bike was imbued with a clear vision and purpose rather than just being a generic class 3 ebike.  A long process of testing, prototyping, and implementing design modifications means that the final product is mindful of the user’s needs for comfort and ease of use.

Another standout feature of our enterprise is the supply chain. We have close relationships throughout the chain, particularly with the factory where our products are made, meaning that we know every little detail of how the product gets made. Due to this, we have a reasonably accurate estimate of how long it takes to produce the product from start to finish.  

This is especially important right now given the supply side shocks in the global economy. Many companies have no real idea of how long a product will take to produce given the great uncertainty in obtaining the right components. We knew we had a huge competitive advantage by knowing every part of our supply chain inside out and having a great culture of communication.

The final step is delivery. As we have a good knowledge of our production chain, as well as good working relationships with our partners handling delivery over in the US and Canada, the delivery service is very smooth.


C3STROM Indiegogo experience

So that covers everything about our experience with launching on Indiegogo. As you can see, we’ve had a great time launching the product. We hope you are now more informed about why we chose this platform and how we managed it.

You’ll also hopefully have a better idea of C3STROM’s unique talents and why we’re not just like all the other ebike companies around. Even though it’s a tough time in the ebike market right now, our rugged persistence in the design process and our close relationship with the factory where are products are made mean we have an outstanding ability to get the product shipped. This is rare right now in just about any market for physical goods, let alone the ebike market specifically.

If you have any more questions or queries, please feel free to send us a message and we will get back to you as soon as possible. We’ll be more than happy to – we pride ourselves on our relationship with our customers and backers!

The final verdict: our riders tell all at the LA Area support center

Our C3STROM family is at the heart of all we do. It is the stories and adventures that you guys share with us that really inspire our team to continue doing what are love and celebrate with you. Sharing the stories of you wonderful riders is an integral part of our work, which makes our announcement today all the more special. Our cherished customers here will give you a sample of what you can expect when you first take a C3STROM bike onto the road. You might be curious about what features really stuck out to our riders. Or you might wonder about what aspects of the bike you do not know about yet. Our riders talk about it all: from aesthetics to speed to comfort.

We’d like to introduce you to the premiere of our new series, entitled ‘On the road’, in which we routinely highlight our C3STROM test riders and share their unique experiences. Kicking this series off is the head of C3STROM LA Area technical support center, Tim Park. See what he has to say in the three episodes of ‘On the road’ below. We’re sure you’ll love watching these great interactions, as they give better insight into how our bikes work in action and how riders are reacting to the experience of riding a C3STROM bike for the first time.



What Chief liked most was the weight – coming in at just 95 pounds, it was a lot lighter than other bikes like the Sur-Ron. He also liked the fact that the C3STROM is packed full of fantastic features straight out of the box. The value for money was just too good for Chief to pass up the opportunity. We focused a lot on including a wonderful set of features at a price tag you can afford.

After Chief took the bike for the ride, he was shocked by how quiet the bike is. Chief is also a sucker for striking, beautiful design – he said that many people commented on how awesome the bike looked! They had never seen an ebike so elegant and distinctive before. If you want to have an ebike that differentiates itself a bit from the run of the mill, you should seriously consider giving ASTRO PRO a go.

The distinctive look doesn’t come at the price of practicality. Chief said it was great that the bike could be used for storage, making it incredibly useful to go to work or out for an adventure on the weekend. So, if you’re someone who needs to take a lot on the go, the ASTRO is the perfect bike to facilitate you. It’s surprising how many rides an ebike is suitable for that you once thought was only reserved for a car.  

Of course, Chief was also impressed with the speed – ‘that’s good power’. But most importantly, the bike is versatile, as Chief commented that you could take it to the beach, to work, or elsewhere. All in all, he summarized the bike by saying it is the number one model for its – ‘there’s no competition at all’.



George was attracted to the bike’s aesthetics. He particularly loved how it looked like a motorcycle, with an eye-catching and bold frame. It’s certainly a very distinctive bike – many of our customers have said that they bought the bike purely for the look alone. He also appreciated that he could buy the bike locally at EM bikes in the LA area, which gave him reassurance as a consumer as he could test the bike first.

Upon riding the bike, George loved the pedal assist feature. You can see in the video above just how smoothly the bike transitioned into the pedal assist mode. When riding in this mode, George found the bike to be ‘super-fast’. Most riders are surprised by what 28km/h feels like on a bike – it gets you to your destination more quickly than you’d imagine.

For someone like George, who needs a bike that has both great performance and a great look, the ASTRO PRO is great. He can travel round the city and be proud of his ride, while also being confident that it can get him from A to B efficiently and safely. Many users are struck by just how versatile the bike truly is, being an all-rounder that excels in many categories.

It’s always nice to see a customer with a genuine smile on their face after testing the bike and looking forward to riding it after their purchase. We can when a customer like George really appreciates our product, which gives us a great sense of pride and service to the riding community. George ends his summary of the bike by saying he was ‘shocked’ by the quality of the item – ‘I’m ready to ride it! I can’t wait!’.



As he makes clear in this video, Andy is experienced in using many types of ebikes and has a deep knowledge of what constitutes a quality vehicle. He was buying this present as a gift for his daughter and wife, so we were honored that such an experienced rider would consider our bike to be of high enough quality to give to a loved one. We value Andrew’s judgement very highly and were delighted to find that such an experienced user had a great time on our bike!

Andy liked the ‘beef’, ‘rigid’ motorcycle aesthetic. It gave him a strong impression that the bike is well-built and sturdy, ideal for most types of terrains. After trying it out, he quipped that he felt as if he could throw it off a cliff and it would still be ok (but don’t try this!). If you need the functions of an ebike, but your heart really desires the look and feel of a motorcycle, the ASTRO is the bike for you.

Later, he reported that it felt incredibly comfortable – the silicon seat offers luxury padding to ensure a smooth ride no matter the distance. He particularly liked how the breaks felt super sharp, making them optimally sensitive to the rider’s reaction.

Andy also noticed the power, joking that the bike felt very ‘torque-y’ – the torque is a whopping 80nm! He noted that the bike started and stopped particularly quickly. So, you don’t have to worry about whether the bike will ‘feel’ like a real bike that can just be used without thought of a motor – it’ll feel totally natural, exactly in the old familiar way.

Andy is 6 ft 5 and said he felt a tiny bit to big for the bike – prospective customers should know that the bike is ideally designed for heights between 5 ft 3 and 6 ft 3. Luckily, in Andy’s case, he was buying the bike for his daughter and wife who are both around the 5 ft 6 mark, making it a perfect gift. Be sure to measure yourself before buying the bike.

Ultimately, Andy seemed incredibly satisfied with the bike. When asked whether he approved of the bike, there were no second thoughts – ‘definitely!’ he replied with no hesitation. We hope you too will love this bike without qualification. Because we sure loved making it.


The ASTRO Pro – perfect for individuals

All in all, the ASTRO appears to be very popular with our first round of customers. We’re always so pleased to hear that the final product has met all the desires of our target audience. The product finally feels like it’s complete and a success when we see smiles and hear compliments like these.

What we’re happiest most about is the fact that the customers value in the product exactly what we intended to deliver. Each customer mentioned the design aesthetics – something we put a huge amount of effort into with our own dedicated research team. Many also mentioned the speed and brakes – another key focus point of ours.

The work seems to have paid off!

They saw that the product is a fantastic mix of different elements – something that is very difficult to achieve at such an affordable price tag. Such a feat was very difficult for our team to pull off, so it’s great that these guys found our product out of the many items on the market today.

If you also want to test an ASTRO, you can either contact us or the LA technical support center.

C3STROM Set to Launch ASTRO & ASTRO PRO May 25 on Indiegogo

C3STROM, a trailblazer in hi-tech electric bikes, today announced the crowdfunding launch of the ASTRO and ASTRO PRO, its multi-terrain, precision designed, class 3 bike. This model series features an impressive balance of battery power, eye-catching build, smooth ride, and safety features until now unavailable in a two-wheeler.

“The ASTRO’s release marks a new level for the all-in-one electric bike,” said Harry Chan, C3STROM CEO. “The story here was just us asking, why are riders supposed to choose between looks, comfort, speed, and adaptability? They shouldn’t have to, and now they don’t have to; this model’s specs and reviews speak for themselves.”

The ASTRO Arrives

C3STROM’s new outing has been met with much anticipation given its package of snazzy looks, purposeful design and functional road tech. The off-road capable ASTRO underlines safety with 4 piston hydraulic brakes, high lumen LED 130 Lux headlights and signaling integrated tail lights. Despite its enviable top speeds of 28 mph in C3 and 32 mph in off-road mode, comfort was clearly prioritized here. The silicone saddle, pedal-assist features, 5 riding mode levels, and adjustable front forks combined with an asymmetrical human-centered aluminum frame for a cozy riding experience.

For those looking to travel far, the removable lithium-ion battery offers a maximum range of 78 miles and a quick charging turnaround of 4-5 hours. The dual-mode Class 3 and off-road options are powered by the 750W expands options tremendously, a perk that won’t go unnoticed by all types of riders. As a class 3 e-bike, the versatile ASTRO is also legal to use without a license. 

With its striking racing and motorized image, the ASTRO and ASTRO PRO may break right through aesthetic limitations plagued by other bikes on the market, but it is also decked out with convenience through its APP-controlled functions and dazzling range of optional accessories. 





Price Revealed

The company announced today that the ASTRO and ASTRO PRO will be available through their Indiegogo launch, coming in at an early bird price of $1,699 and $1,899, respectively. The selected crowdfunding price confirms C3STROM’s sincere intention to deliver a cutting-edge quality to E-bike enthusiasts. Undergirding that competitive pricing is, of course, a 1-year warranty. 


With a proud, decade-long tenure in the e-bike arena, the parent company of C3STROM was established in Hong Kong by forging a seamless blend of innovation and dependability. The founders are engineers, designers, green activists and most importantly, passionate riders. The start-up has already revolutionized road performance, aesthetics and comfort through cutting-edge tech and precise, balanced design. When they set out 2 years ago, their goal was to bring revolutionary e-bikes to the world market and unchain people from the traditional, unsustainable modes of transportation, leading to a life-changing ride. 

E-bike Regulations of the United States 

The United States E-bike regulations

Ebikes are a fun, easy and convenient way to get around. They are perfect for those who need a vehicle with speed but can’t stand the idea of being tied down to a car all the time.  It’s such an exciting experience to get your hands on a new piece of technology like this!

But it’s important not to get too ahead of ourselves in all the excitement!

There are some important things you should know before you begin your ebike journey. One very important one is ebike regulations. As you might know, different countries have different regulations for ebikes. It’s important to know what kind of ebikes you can drive in your area, as all areas are different.

Here we explain the key things you need to know about all things regulations when it comes to ebikes.

Most of our customers are in the United States, which has quite a complicated legal arrangement when it comes to ebikes. Here we will give you the key facts regarding federal and state legislation when it comes to ebikes.


There are a few important federal regulations regarding ebikes. First, the motor must be less than 750w. To comply with this standard, the ASTRO and ASTRO PRO use a BAFANG 750w hub motor.

Second, the top speed using the throttle must be capped at 20mph when using the throttle alone. Notably, the law does not specify the maximum speed that the bike can go when using a combination  of peddling and the throttle. In fact, the Consumer Product Safety Commission specifically clarified this issue by stating that e-bikes can travel faster than 20mph when using pedals and the throttle.




There are also some regulations that vary by state. The state regulations mostly focus on whether ebikes are classified as scooters, mopeds or traditional bikes.

Only 44 states have definitions for ebikes in their legislation distinguishing them from other vehicles. The other 6 states classify them simply as mopeds or motor vehicles, meaning the same rules that apply to mopeds or motor vehicles apply to them.

In 26 states, ebikes are categorized ebikes into 3 standard classes. The remaining 18 states use unique classification systems.

States using the standard 3 classes:

Arizona, Arkansas, California*, Colorado, Connecticut, Florida, Georgia, Idaho, Illinois, Indiana, Maine, Maryland, Michigan, New Hampshire, New Jersey, Ohio, Oklahoma, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, Wyoming

States using unique definitions:

Hawaii, Oregon, Nevada, Montana, Minnesota, Idaho, Nebraska, Kansas, Kentucky, Mississippi, North Carolina, South Carolina, Washington DC, Delaware, New Jersey, Pennsylvania, Rhode Island

States with no definition:

North Dakota, Missouri, New Mexico, Alabama, Massachusetts, Alaska

The 26 states have pretty much the same definitions and regulations for the different classes of ebikes. The only exception is *California, where all ebikes cannot have a throttle. In all the other 25 states, including New York, a throttle is permitted.

Things get a bit trickier with the states that have unique definitions. Each one is different and it’s worth looking up the specific legislation of these states if you need to drive an ebike there.

For instance, Kentucky and Mississippi treat all ebikes as traditional bicycle that can be used freely on bicycle and multi-use paths. No license, registration or insurance is required. Whereas West Virginia does not recognise class 2 ebikes, only allowing the use of class 3 and class 1 ebikes.

New Jersey has a more complicated two-tier system, where ‘Low Speed Electric Bicycles’ that go below 20 mph (like ‘Class 1) are treated as traditional bikes, while ‘Motorized bicycles’ that can go between 20mph and 28mph are treated more like motor vehicles that require a driver’s license, registration, insurance, and a helmet.


What about the ASTRO and ASTRO PRO?

C3STROM’s ASTRO is a class 3 bike. It has a BAFANG 750W motor, which is the maximum wattage allowed for this class. It has a setting with an initial speed limit setting of 28mph, along with a pedal assist system (PAS) so you can switch between riding it like a normal bike and riding it fast. Therefore, when riding in the initial mode, license and insurance is not required.

It also has another setting called ‘OFF-ROAD’ mode which can be used off-road at a higher speed. As the bike is designed for speed-seekers, we decided to include this off-road mode for those who enjoy the thrill of riding.

For our future EU customers, we have a different riding mode called ‘pedelec mode’. Every time the user starts the bike, it will be set automatically in pedelec mode with a 25km/h speed limit. In pedelec mode, when a speed of 25km/h is reached, the pedal assistance cuts out.


What about licenses and insurance?

If the bike comes under the standard three tier classification system used in the 26 states mentioned above, then generally it does not need a licence and insurance. As for the 14 states with unique definitions, it varies state by state. Generally, ebikes are classed as traditional bicycles or class 3 ebikes in these states so will not require licences and insurance with the exception of New Jersey (see above). But make sure to check your states guidelines for more details, as legislation is often nuanced in these states and subject to frequent changes and revisions.

Ebike Classes of the United States

US ebike classes

When you first discover ebike, the whole concept just seems fascinating! An electric bike that can function both like normal bike and a motor powdered vehicle just seems convenient and modern. You might very quickly get carried away looking for your dream bike.

It can get a bit confusing, though, once you start thinking about what kind of vehicle an ebike is though. You might be thinking is it a motorcycle, a traditional bike or somewhere in between? More importantly, what are the rules that apply to an ebike?

Luckily, in most places there is classification system that helps deal with this problem.

In the United States, the state law of 26 states divides ebikes into three different classes. Each class of ebike caters to a different type of user with certain needs, but also come with a different set of regulations governing their use. Which class a user wants to choose will be mainly based on whether they want to travel in urban or rural environments. It will also depend on how fast the rider needs the bike to go and if they need to be able to use the bike in all the places a traditional push bike can be used.  


ebike classes in the US

In twenty-six states of the US, there are three different classes of ebike. There are eighteen states that use unique classification systems. There are five states, there is no legal definition for ebikes (meaning they are classed as other types of vehicles).

Here are the 26 states that use the standardized three tier classification:

Arizona, Arkansas, California, Colorado, Connecticut, Florida, Georgia, Idaho, Illinois, Indiana, Maine, Maryland, Michigan, New Hampshire, New Jersey, Ohio, Oklahoma, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, Wyoming

Each class defines ebikes by three things: (1) if they have a throttle, (2) how fast they can travel and (3) if they have a PAS (Pedal Assist System, which gives an extra electric ‘boost’ to the bike when you pedal).


The first class of ebike has a top speed of 20mph. It does not have a throttle, so it relies totally on the PAS for power. It’s best to think of this kind of ebike as similar to a traditional bike with just a little bike of electrical assistance, as it cannot go to very fast speeds. These ebikes are treated by a lot of states like traditional mountain or pavement bikes, so they are most suited to dedicated bike lanes, roads, and trails.


The second class of ebikes also has a top speed of 20mph. However, it also has a throttle used in combination with the PAS. It can’t go any faster than the ordinary class one, but it is a bit easier on the rider as they can choose if they want to use the pedals. Again, these ebikes are often treated like normal traditional bikes and can often go wherever those ones can, but it depends on the state. Some states like New York and Michigan State have restrictions.


The third class of ebikes has a top speed of 28mph. There is also another regulation on the motor for this class – it must be less than 750 watts.

Whether or not it is allowed a throttle depends on the local regulations. In somewhere like California, for instance, throttles are not allowed. Whereas in New York, a throttle is totally fine. It also has PAS, so the rider can switch between PAS and throttle.

These ebikes are often more suitable for roads and on-road bike lanes, but often cannot be used on standard off-road bike lanes and trails because they are too fast.


What class is our ASTRO and ASTRO PRO?

C3STROM’s ASTRO is a class 3 ebike. It has a BAFANG 750W hub motor, which is the maximum wattage allowed for this class of bike. Initially, when you turn on the bike, the maximum speed is capped at 28mph with pedals and 20mph on throttle only – which is the maximum speed for this class. When riding in this default riding setting, the bike fits the standards of the class 3 ebike category mentioned above in this article, meaning the bike does not require a license or insurance (in most states).


As the bike fits the requirements for a class 3 ebike, legally, that means it is in a special class of vehicles which has a unique set of regulations that apply to it. As mentioned above, the rules and regulations vary by state; some states do not even use this classification system and others use a modified version of it. Subsequently, it’s important to check rules and regulations for ebikes in your own state before riding. In most states, however, the ASTRO and ASTRO PRO will be treated as a special type of vehicle that is closer in legal status to a traditional bike than a motor vehicle like a car or motorcycle. That’s why you won’t need a special license or insurance in most cases.

For our future EU customers, we will have a different default riding mode called ‘pedelec mode’. In pedelec mode, when a speed of 25km/h is reached, the pedal assistance cuts out automatically. The bike will be in line with EU legal requirements for ebikes, as the requirements specifically state that bikes must not go beyond 25mph with pedal assistance. Therefore, the bike will not require any special license or insurance.

Hi Bikers

To bikers,

This is a late letter, given that C3STROM is a new brand and bikers know almost nothing about us, we should have introduced ourselves and ASTRO‘s development to you a long time ago. We had no choice but to work 13 hours a day as our team was in its start-up phase, and after finishing basic everyday work, we finally have time to chat with everyone here, sincerely, rather than officially and formally.

Why we decided to design ASTRO

Our founders are e-bike engineers, designers, and passionate riders, the majority of our members have more than 10 years of experience in the industry. Under the influence of the COVID-19, we like any other people gave up driving and public transportation and chose to commute by e-bike concerning the economic situation and safety. When we started selecting e-bikes, we were surprised that even though there are many brands and models on the market, we seem like just can’t pick out a satisfactory model. There are some cool-looking models with a high price and low configuration, some moderately priced models with good configuration but not cool looking, and some ordinary-looking models with low price and configuration. In short, we couldn’t find the e-bike we wanted, so we thought, why don’t we design our own cool-looking, super-equipped, and affordable e-bike?

ASTRO‘s Marketing Positioning

When we had the idea, we couldn’t wait to make it live. I still remember the excitement on everyone’s face at that time, after the passionate collision of ideas, we decided to design an e-bike with modern motorcycle features: cool appearance, fast speed, long mileage, and comfortable riding, at the same time it must comply with the law, no license plate needed. The appearance must be unique so that people can not forget at first glance, high configuration, conquer the most critical bikers, reasonable design, good quality, can cope with complex riding road conditions, after about two months of design and repeated modifications, ASTRO’s design drawings came out, it’s that gorgeous of our dreams!




How do we make the dream come true?

Because of the unique appearance of ASTRO, the development of mechanical parts is the most difficult to achieve. Many accessories require individual mold development, including the frame, saddle, front and rear lights, rear rack, carry bag, mudguard, mudguard connectors, etc… The hardest part is the frame, although we claim that the sample has gone over two generations of development, the frame has at least three generations of manual proofing. To adapt to the battery, and extended silicone saddle, we adjusted the size and appearance of the frame design, and to strengthen the frame, we added more design, the final product differs from the initial design.








Behind the Specification

Mechanical parts determine the strength and riding comfort of an e-bike, while electrical parts determine the smoothness of an e-bike. A perfect e-bike must be one with quick acceleration, fast speed, and long mileage. Riders can check the riding data at any time to understand the current status of the e-bike. we have detailed the configurations and data of ASTRO in the specification. Here I would like to explain the considerations behind ASTRO and related accessories from another perspective.

  • Fast

          Bafang 750W motor with 80n.m torque, 2000W peak power; 18mosfet 35A big controller, solid frame

  • Long range

          Samsung 21700 780/1080Wh battery

  • Safety

          4 piston motorcycle brake system, The same high and low beam, turn signal, brake light system as the car, super         solid frame

  • Convenience

          4A leading charger, removable battery, USB charging port, and smart battery BMS & controller could transport every data to display through a customized APP.

  • Riding experience

         Extented silicone saddle, 56T big crown, 20”frame size

Why hard-tail?

I know you must still have questions. ASTRO is a hard-tail e-bike, only the front fork has shock absorption. About this part, we discussed repeatedly during the design phase, that the hardtail is more efficient for speed, on the other hand, the soft tail is better at shock absorbing and more comfortable to ride, but the soft tail version takes longer to develop and costs more. We couldn’t wait to introduce ASTRO to everyone, as a startup team we had to learn the trade-offs. After the release of ASTRO, most bikers are very satisfied with ASTRO’s exterior design and most of the configurations, and of course the price.

Dissatisfied? The hardtail version was brought up the most, followed by the mention of the chain and footpegs being too close to the ground and the lack of protective cover. We have considered all these issues and hope you will support C3STROM so that we can afford to develop V2, a soft tail version based on V1, and other minor issues.

At last, we are very happy that ASTRO is successfully released, you may be attracted to join the C3STROM community by ASTRO’s appearance or the early bird price of crowdfunding. It doesn’t matter, I believe most of you and geeks can see the strong technical background of the C3STROM team through the design and specification of ASTRO. At present we have achieved mass production, we are different from some of the projects released on Indiegogo, we are ready for production and development. We chose to debut on Indiegogo, from the perspective of marketing, so this is almost a project without the risk of receiving goods. The first stage price during the crowdfunding has been released, and we hope that you will seize the opportunity to buy the Super Early Bird perk, because the cost of ASTRO development is very high, and we can only provide a limited number of super early bird perk as a real benefit for the initial C3STROM riders.

In the next post, we will further introduce the story behind the project. We have invited experts in the cycling industry to review it and some of the videos are already online. If you would like to learn more about C3STROM, we invite you to visit the following channels, in particular the C3STROM Youtube channel.

C3STROM Official Website:

YouTube: C3STROM

Instagram: c3strom


2022 May 25

How to Make Your E-bike Go Further (E2)

Continued from the previous article The Secret of Ultra-Long Life Span – How to Make Your E-Bike Go Further (E1)

Many people wonder how far they can ride an electric-assist bike, but businesses are often unable to provide an accurate answer because there are so many variables. So, how can you ride further under the given configuration conditions? Here is a list of general tips for your reference, following the previous article on The Secret of Ultra-Long Life Span – How to Make Your E-bike Go Further (E1).

  1. Tires

Lightweight tires may appear appealing and logical, but they should not be chosen. This is a “false economy” product that will negatively impact your ride. Because of the extra weight, you will use the sidewall more on an electric bike, and because the rear wheel is difficult to get off the ground, it will take more force when hitting rocks and roots.

Higher tire pressure and heavy-duty tires are required to avoid frequent sidewall punctures. While weight is one of the influencing factors for range longevity, durability and size must also be considered.

  1. Brakes

Don’t skimp on efficient brakes, just like you wouldn’t on tires. Upgrade to four-piston brakes if possible. You’ll improve your power by braking less frequently and only when necessary. And a thousand reminders to check your brake pads for wear frequently before, during, and after a ride, and to always keep spare pads on hand.

  1. Chains and Guide Pulleys

A clean, well-lubricated, and free-rolling chain experiences far less resistance than a dirty, poorly maintained chain. And, especially when shifting uphill, the motor can put a lot of strain on the drive train. So, as detailed in the How to Maintain Your Electric Bike article on how to clean your chain, check for wear and tear regularly and keep it well lubricated.

  1. Turning

Leaning your e-bike into a turn requires more muscle power, but once your balance and center of gravity are correct, the weight of the bike will maintain consistent traction. To get a longer ride, avoid bouncing between turns and instead take a more cautious approach. Try pedaling around corners while keeping the motor running on slight uphill or flat gentle turns. If you think you’re going too fast, slow down but keep the cranks turning. We discovered that this continuous and calmer motion consumes less energy than braking and then skidding.

  1. Climbing a hill

Remember to shift into neutral before pressing the power button. Again, high cadence is essential. Find a comfortable seat that allows you to keep your weight on the rear wheel. An e-front bike’s wheel is less likely to lift, allowing you to sit up straighter and concentrate on traction. Shift down through the flywheel to keep the motor running at a high cadence. Keep your gaze on the horizon; don’t be concerned about a slick course; instead, concentrate on maintaining power.

  1. Downhill

Don’t forget to set the downhill mode to “energy saving.” Even if you believe it makes no difference because you won’t be pedaling much at this time. But it works, and over the course of a 30-40km ride, it all adds up. Don’t think about accelerating sharply once the speed exceeds the speed limiter (25kph/15.5mph). Instead, keep a steady cadence and maintain your impulse in the turns. Rather than pedaling, accelerate, as the bike will not accelerate without this assistance. Don’t be concerned about roots and rocks; you won’t be able to jump up like a normal bike, and you’ll take them out anyway. Consider going bigger and wider!

How to Make Your E-bike Go Further (E1)

E-bike can usually be ridden more frequently than regular bikes, but who wouldn’t want to have more longevity? So, what are the requirements for getting the most out of an electric-assist battery and motor?

Even the best electric-assist mountain bikes can cause headaches due to range if ridden in an inappropriate manner or set up incorrectly. This is the time to pay attention to the ten super helpful tips that will extend the range of your electric-assist bike ride!

  1. Power mode

Please use the battery’s “smart” mode. For example, use Bosch’s eMTB mode, or launch the bicycle motor manufacturer’s app on your phone to see how the motor is configured. Simply reduce the power levels or choose one of the preset values. Shimano’s “Explorer” mode, for example, maybe better for you than its default “Dynamic” preset. Many Shimano STEPS users, for example, now prefer to stay in “Eco” mode for 95 percent of the stroke and only use the low-power “Boost” mode for the remaining 5% of the stroke. Bypass Trail mode entirely. It’s also critical to keep your e-bike’s firmware in good working order by using the most recent software. This is typically accomplished through the use of Bluetooth on your phone, so it should be fairly simple, right?

For example, the Bafang mid-motor system typically has 5 gears for riders to choose from; however, except for the long and difficult steep slopes that inevitably necessitate strong power mode, 2-3 gears can handle more than 70% of road conditions; While the TENTEN power mid-motor system equipped by BESTRONG Travel has different modes of ECO, NORMAL, SPORT, and TURBO, it also has the i-SPORT automatic mode, which will automatically adjust the power output based on the current load. Furthermore, there is an i-SPORT automatic mode that will automatically adjust the output power based on the current state, and selecting the right power mode during the ride can help you save a lot of electricity.

  1. Shifting gears

This is a common mistake made by e-bike owners, namely ignoring the transmission. When you are unable to pedal, do not simply turn the turnbuckle; instead, apply pressure to the motor and battery. Adjust your gear ratios to make your e-bike last longer and ride farther; after all, it is still primarily a human-powered bike.

  1. Pedaling frequency

Any mechanic at a bike shop will tell you that the most serious issue that some electric-assist cyclists face is an addiction to pedaling frequency. This not only consumes power faster (causing customers to complain about not getting the advertised mileage), but it also drains the powertrain faster than it’s worth.

To keep the motor running at full power, you must pedal rather than skid. Pedal at a speed of 70 to 90 RPM. You’ll get the most assistance if you keep turning the crank. When the pedaling frequency falls, the motor slows down, which is especially inconvenient on steep climbs. Because electric-assist bikes benefit from a wide range of 1x drivetrains, you’ll need to change gears frequently to optimize your pedaling frequency.

For the next episode, please click: The Secret of Ultra-long Life Span – How to Make Your E-bike Go Further (E2)

How many degrees of slope can the bike climb

How many degrees of slope can you climb?

This is a topic that is prone to bragging solitaire, and the fact that people frequently confuse two different units of slope measurement makes this topic contentious.

We join Rhett Allen, a physics professor at Southeastern Louisiana University, in this article to discover the limits of bike climbing.

The first definition of slope is the steepness of the surface unit; typically, the slope I is the ratio of vertical height h to horizontal distance l. Both percentage and degree are expressions of slope; the percentage formula is vertical height / horizontal distance * 100 percent, and the degree formula is tanα = vertical height / horizontal distance.

Consider the following examples.

A highway has a maximum slope of 5%, 3°.

The maximum slope of a parking garage is 15%, 8°.

The climbing capacity of a car is 36%, 20°. Certain off-road vehicles can climb 60%, almost 30°, which is the slope of stairs in an ordinary building.

100% slope is 45 °, almost a cliff feeling.

How steep a hill can be climbed does not depend on power.

“If you don’t care about the speed of climbing, say a fraction of a meter per second, you can keep climbing with very little friction. It’s like lifting a heavy object with a pulley that only requires a small motor.”

Rhett Allain is a physics professor at Southeastern Louisiana University who writes a physics science column for Wired magazine.

In theory, as long as the right gear ratio is found, a very small amount of power is sufficient to sustain the climb.

However, a very small gear ratio requires the rider to turn his legs like crazy, maintain a very high pedaling frequency, and if he is not careful, he will fall off the bike because it is too slow.

When combined with the actual situation, the climb’s speed could not be too slow, so Professor Allan set the climb’s minimum speed to walking speed, 2 meters per second. Then he performed extremely complex calculations in a very professional physics manner, eventually determining that 40 percent gradient is the maximum gradient that the bike can challenge, at which point it must do 422 watts of work, a power value that professional cyclists almost always achieve.

If you want to split hairs and see how far the slope goes, no matter how much power we output or what gear ratio the bike has, we can’t go up another meter, and the center of gravity becomes a keyword.

The only thing you can’t get past is the center of gravity.

We all know that when the slope steepens to a certain point, we fall backward.

We fall back when the vertical extension of the rider’s center of gravity with the ground is not between the contact points of the two wheels and the ground.

And, more specifically, where is the cyclist’s center of gravity?

Keith Bontrager, an elite-level Bikefitting mechanic, says this is difficult to explain conceptually, but he generally sets the center of gravity 3 to 4 cm behind the pedals when the crank is at the nine-o’clock position on the cassette side.

To determine the point at which the cyclist falls back, we must perform a trigonometric calculation: Tilt angle = 90° – [Tan-1 (height of the center of gravity horizontal distance from where the rear wheel lands to the center of gravity)]

This formula yields a critical point of 25.8°, corresponding to a 48 percent gradient. Of course, this is true if the rider remains seated in the car seat throughout the climb.

When the angle becomes too steep, we all have to leave the cushion and rock up to two steps.

If the center of gravity for this stance rocker is recalculated, a new critical point of 41°, or 86.9 percent, is obtained. This appears to allow the rider to conquer any crag, putting off-road jeeps to shame.

However, one factor, the friction between the tires and the ground, is significantly underestimated in this set of calculations. Anyone who drives knows that when the slope is too steep, the tires slip, and bicycles are no exception.

The first disappointment is always the tire friction.

Hristian Wurmbäck, a product manager for Maersk tires, states unequivocally that tire friction will be the first thing to fail when climbing steep hills.

“The coefficient of friction of a complex compound such as rubber is difficult to predict: is it dry, is it wet, how dry is it, how wet is it… You’ll never find the perfect one that can be used in every situation.”

“From asphalt to wet mixed soil surfaces, the coefficient of friction performance of the tires ranged from 0.3 to 0.9.”

Professor Allan optimistically set the coefficient of friction at 0.8, but after applying his complex formula, the friction of the tires could only support a 38.7° climb, or roughly 80% of the grade.

However, the estimate of 0.8 is always too optimistic, considering that 30% of road construction ramps are made of concrete, not asphalt gravel roads, and the coefficient of friction of rubber drops to 0.6 during movement and applying Professor Alain’s formula, the slope obtained is approximately 60%.

Even if you’re confident you have enough power, the right sizing ratio, and exceptional center of gravity control, you’ll be beaten by a 60% steeper grade because your tires will let you down unless you keep a bottle of 502 in your cycling suit at all times.

The good news is that an HC climb (short for hors CATégorie in French, meaning “outside the class” and denoting the most difficult climb) is only a 10km or more climb with an average gradient of 7.5 percent, according to the UCI.