This review was provided for free, but C3STROM did provide a temporary demo bike and accessories for me to test. My goal is to be transparent and unbiased with you, this video and writeup are not meant to be an endorsement of C3STROM products. I welcome your corrections, additions, and feedback in the comments below, and the C3STROM electric bike forums.
Observations:
- C3STROM was launched in 2022, but is made up of an international team that has been working in the ebike industry for 12 years. Their first product, the Astro, is being launched on Indiegogo and comes in the standard and Pro version, which has a higher capacity 20 amp hour battery pack.
- The company appears to be based in China and is a true manufacturer vs. middle-man brand. They have secured a North America headquarters warehouse in California and partnered with an established brand that will oversee distribution and support for their one year warranty.
- I asked about the company name and was told that it is an abbreviation of “Class 3” since the product is high speed, and a made up word that sounds similar to storm. The Astro name was chosen because it resembles the word astronaut and astronomy, the bike is futuristic and meant to look space age.
Pros:
- The bike looks really cool, I appreciate that C3STROM is doing it in two colors (silver and dark gray) and added plastic accents to the frame behind where the battery mounts. They look like air intakes you would see on the hood of a sports car. Notice the smooth welds, the downhill double crown suspension fork, the matching fenders with extra side supports. I also like how the battery pack resembles a gas tank on an traditional motorcycle.
- Excellent integrated lights. The headlight has an “always on” running light strip that looks cool, and the main beam is very bright… there’s even a high beam (using the switch near the right grip). To activate the headlight though, you must click the power button on the button pad near the left grip. The rear light wraps around so it’s highly visible, it has a bright mode when the brakes are pulled (and there are also motor inhibitors connected to the brake levers) and the rear light also animates to the left or right when the turn signals are active. There are two turn signal modules at the front of the bike which look nice and are flexible.
- Super powerful experience, even though the bike is heavy. The planetary geared hub motor is rated at 750 watts nominal, and the controller is rated at 28 Amps. They say it offers 80 newton meters of torque, which is a lot for a hub motor. The bike feels zippy and smooth, but there is some whirring motor noise that you might notice in the video review. I was actually surprised to hear it, considering the aluminum alloy encasement.
- The heavier build of the bike, along with the thicker tires and suspension, helps it feel very smooth and comfortable. The bike doesn’t vibrate, and the suspension fork was very smooth. I appreciate that it has a sturdy double crown design, like a downhill mountain bike, and also has lockout and preload adjust.
- The 24 magnet cadence sensor is very responsive, but I preferred to use the throttle most because pedaling was limited by the seating position and fixed saddle height. The throttle offers full power output in any of the five assist levels, so you don’t have to click + and – to add power, it’s configured the way I prefer it.
- I really like the rims, thick puncture resistant tires, and Wellgo platform pedals they chose. All of the touch points are nice, including the gel saddle, and I like how the grips are locking vs. cheaper ones.
- The optional rear rack design is pretty cool looking, only costs $50, appears to be very sturdy with a 55lb weight rating, and is very functional. There’s a sturdy top platform for trunk bags or baskets, a side rail for panniers to clip to, and a large bungee loop at the bottom. I was told that they may sell an additional battery pack to mount to the rear rack for extended range and the bike is pre-wired to work with this.
- Lots of additional mounting points for bottle cages, folding locks, portable pumps, and other accessories on the downtube and controller box bottom bracket area. There’s even a bolt on the top tube for a future cup holder option from C3STROM.
- Many moped minibike style electric bikes that weigh more and have the long seat have single speed or very basic drivetrains. C3STROM went above and beyond by upgrading to a Shimano Altus derailleur and using a DNP nickel plated freewheel with wide 11-34 tooth range. That big gear is critical if you have to pedal without any electric assist support, or climb a super steep hill. Great choice! It still felt good at high speed too, because of the large 52 tooth chainring and smaller 11 tooth cog. This allows for higher speed Class 3 performance since the throttle is set to cutout at 20mph by default.
- With any heavy fast electric bike, it’s important to have good brakes. The Astro comes with large 180mm rotors that provide a good mechanical advantage over the smaller 20″ wheels, and the calipers are quad piston vs. standard dual piston. I was also told that they are using calipers from a motorcycle company vs. bike components. The hydraulic system is beefed up with larger reservoirs, and the three-finger brake levers have balled ends, which is a requirement for motorcycles to improve safety. Both brake levers have motor inhibitors, activate the rear light in bright mode, and offer adjustable reach.
- I didn’t get to test the fenders with water, but they seemed to offer decent protection for your upper body, face, and back. They were solid and didn’t rattle during my faster rides and off-road tests.
- To me, the kickstand looks like an ordinary bicycle kickstand, but it supported the higher weight of the Astro Pro very well. I believe it’s adjustable too, good positioning as not to cause pedal lock.
- I appreciate that the company didn’t go nuts with graphics. The C3 logo punched into the metal gusset near the steer tube is very cool, the black chevron stickers are tasteful, and the tiny black and red C3STROM sticker on the downtube is great.
- Even though the battery is a bit high on the frame, it does position the locking cylinder, charge port, and on/off switch in an easy to reach location. I like that the battery can be completely shut off, to keep people from tampering with the display and to protect it from phantom power draw over long periods of disuse. As always, store lithium-ion batteries in a cool dry location and stay above 20% charged to help them last without degradation.
- The battery charger that comes with the bike is perfect for this thing, it’s a bit large and heavy, but offers 4 amp output for much faster filling. That’s important when you’re dealing with a 1kwh+ sized battery pack.
- Large display panel is easy to read, and can be swiveled to reduce glare. The grayscale looks nice, has a faint green glow that won’t ruin night vision, and is transflective so it looks great even in direct sunlight. I really like it.
- The smartphone app is pretty cool, and seems very professional with the graphics and different settings. With it, you can unlock off-road mode for up to 32mph use. This could be great for someone with private property or another situation where you want a moped experience.
- I was impressed that the company is offering a year long comprehensive warranty, and appreciate that they have a US distribution point. They are working with an individual I’ve known before from the ebike space and seen good performance from. I also feel like the product is tough enough that it shouldn’t have a lot of issues.
- It’s pretty amazing that they offer free shipping in the contiguous US and Canada considering how large and heavy the bike is. I like that it comes with the necessary tools, and a great instruction manual with pictures.
- Apparently they are using the high capacity 21700 battery cells, and the manufacturer is Samsung. I recognize the battery pack design as a Reention Dolphin. These are all recognizable companies, and the pack design is more open source and modular than proprietary.
Cons:
- The bike is very heavy compared to most electric bicycles I see, it really resembles a moped in this regard. Weighing 95lbs with the battery and rear rack attached, you can reduce weight by 10lbs by removing the battery. Be careful doing this, because the battery can be difficult to reach, slide, and lower down through the frame tubing. It’s nice that the bike has walk mode that can be activated by holding – so you don’t have to push it if you aren’t riding.
- The wide hub spacing and cast wheels are not as common for shops and parts dealers, so repairs and replacement could be difficult. Thankfully, the forged rims are very sturdy and won’t go out of true as easily as wire spokes.
- The wide tires require a wide hub spacing and frame, which results in a wider stance and saddle. I think that regular pedaling could chaff the inside of thighs, especially if wearing pants. The saddle is very comfortable to sit on, but does not go up and down like most bicycles, so achieving full leg extension is difficult and pedaling just isn’t as effective.
- I appreciate comfort, especially on faster electric bikes. The adjustable suspension fork, high volume tires, and gel saddle go a long way, but there’s no way to add a suspension seat post since there is no seat post here. This also limits pedaling position so you cannot easily adjust for full leg extension. They say the bike is designed to fit riders 165mm to 185mm tall.
- This is a minor thing, but the twist shifter is on the left side of the handlebar vs. the right, and it had to be flipped upside down. As a result, the readouts are inverted and the housing wire blocks the USB charging port that is built into the bottom of the control pad ring on the left. That’s too bad, considering the company has a smartphone app that is pretty cool and it would be nice to charge the phone while riding since the battery offers such high capacity.
- The button ring on the left side of the handlebar can be difficult to reach and press, since you have to reach past the half-grip twist shifter. It’s doable, but definitely a bit of a stretch at times.
- I really like the plastic fenders, but there is no chain cover to keep pants or dress ends from touching the chain. The distance from the chainring to the freewheel is also pretty long, and there’s no slap guard to protect the right chain stay from getting chipped if the chain bounces down. Thankfully, the chainring does have an alloy guard that provides a bit of protection for clothing, the teeth on the alloy chainring itself, and could help reduce outside chain drops.
- The crank arms are standard 170mm length, which might be a little long for the lower bottom bracket and could result in pedal strikes if someone is turning and pedaling simultaneously. Sometimes I see shorter crank arms for folding bikes and those with smaller wheels like this.
- Battery weight is positioned high on the frame vs. low. I appreciate that it’s centered on the frame, but lower weight would improve handling and result in less damage if the bike tips. I was told that the rear rack may support an optional second battery pack, which sounds cool, but that pack would also be high up vs. low and centered.
- Be sure to remove the key from the battery lock cylinder before removing the pack, because it will not fit through the frame when sliding and could result in some scratches or pinched fingers if you forget and try to remove the 10 pound pack with the key still in.
- The wheelbase is longer than most bicycles I test and review, because the tire diameter is smaller. Basically, the overall length is similar, but where the wheels touch the ground is farther apart. This can result in more high-centering and strikes if you ride over tall obstacles, it also makes the bike incompatible with some platform style car racks (like my Küat Sherpa). The extra wide 4.25″ tires also make it difficult to fit on some car racks.
- This company and ebike are being launched on Indiegogo. The exact specs and timing for delivery could change. I chose to cover it because I have covered products from the same distributor before, and they were accurate and on time… but there is always some risk and I want to make that clear. The sample product I got was very polished and worked as expected, perhaps better than I was expecting as the manual was very good.
- This is a very minor complaint, but the turn signals do not click, chime, or flash for the rider when they are active. I found myself forgetting that I had left them on, which could confuse other cyclists and cars.
- Since the bike is very heavy and can potentially be unlocked to travel at high speed, it could put some riders at risk of legal consequences or injury. It’s basically a moped that ships with ebike settings… and the added weight alone presents some risks if there’s a crash. Please be careful, wear protective gear, and think about the consequences of riding an unlicensed vehicle if you ride in unlocked mode on city streets. I do not see a place to add a rear license plate, I am not sure if the bike is DOT approved, and I don’t want to see anyone facing outsized consequences for riding.
- The rear rack is so close to the end of the saddle that some tall trunk bags might not fit. Child seats might also have some issues because of the alloy siding that could block their clamps, and the limited top space because of the seat extension.
- As nice as the lights are, I feel that a motorcycle license plate mount, pedal reflectors, and additional front and rear reflectors would add to to the safety of this ebike. I appreciate that the Bafang rims have white reflectors in them, since the tires are not reflective.
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