BionX Hub Motor Kit Review

March 10, 2013
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The BionX is  the best selling hub motor kit in the United States, and probably  the world. The Bionx is not only sold as a kit, but many manufacturers use it as a turn-key solution to very quickly bring a quality ebike to market. These manufacturers have included, Trek, Ohm,  Smart and Grace.  Unlike most kits, the BionX is designed and manufactured not in China, but in Ontario Canada. At least some of (if not most of) the components of the BionX kit are made in Asia under tight quality controls.

The BionX hub motor comes laced into a wheel. Available wheel sizes are  20″, 24″, 26″ and 700c.  Of course you can always have a wheel builder lace a BionX into your own wheel. The system includes a lithium-ion battery, handlebar-mounted control unit, cool throttle, battery charger, and all the hardware and wire cables required to electrify your bike. It weighs in at 19.4 lbs

I test rode the 36V PL-350W  kit ($1,500). There is also a 24V  250W kit ($999)  and a “premium” 48V kit available. ($2,000).  As of 2012, all  BionX kits are covered by a two-year factory warranty.

Which types of bikes are BionX-able?


Check out our gallery of example BionX kits. Hardtail mountain bikes with front suspension seem to be ideal. Full-suspension bikes are one of the few types of frames not good for a BionX kit because it is sometimes difficult to mount the battery.

The bike I demoed is a Montague folding bike which seemed like an ideal bike to modify because of its excellent battery placement position and its decent retail price (about $700).

BionX options:

You can go with a 250W or a 350W… You can go with the 36V or the 48V…although either 36V 0r 48V will have a 350-watt motor with similar performance.

The BionX comes with two different mounting options. A rear rack mounting option (standard on most conversion bikes) and a triangle mounting version.  Having the battery weight in the triangle makes for a much more balanced ride than a rear rack mounted battery. With the heavy motor and battery in  the rear, your bike will feel unbalanced and seem heavier than it is. If the bike you have selected to convert does not allow the triangle battery, I would  suggest you pick a different bike with adequate space in the frame.

BionX does not offer a front motor mounting option, as most other kit manufacturers do.

To Kit or not to Kit

Many people have old bicycles in their garage gathering dust that they are attached to. Turning it into an electric bike will almost guarantee the bike will see the light of day, and be used more.  The higher quality the donor bike the better an electric bike it will make, and the more likely it will be ridden. The Bionx kit can transform your beloved bike into a cutting edge electric bike.

One  question you may be having  is should you convert an existing bike you rarely use, or buy one of the flashy new factory electric bikes that have been hitting the market lately. This is a hard question, because there is not much of a price difference between a top of the line BionX kit and one of the new Asian-made bikes from companies like Currie, Stromer, Easy Motion and Pedego. It use to be people would convert bikes because there was no store-bought production bike which fit the bill. These days $2,000 will buy a really nice electric bike, and a purpose built electric bike has many advantages over a conversion bike no matter how elegant the kit. The same day I test rode the BionX I also rode as well an Emotion Neo Jumper, which is a good example of a high-end production bike ($4,000 for full-suspension model).  Because bikes like this have a purpose built frame, and its hard to tell they are an electric bike (no rectangular battery to be seen anywhere).


Here is a comparison of the two batteries…of the Neo Jumper and the Bionx Kit. Both are the same size (36V / 9-Ah) and similar chemistry.  As you can see they have different form factors. One is very boxy (BionX) and the other is slick and neat:


One advantage of going with a kit is you can always take the kit off and transform your E-bike back into a regular bike again. And of course the next advantage of the kit is you can convert any bike that has a frame you like, and are not constrained to the factory E-bikes on the market now.

Another advantage of the BionX kit (even though it is expensive) is that it is probably a better financial deal than a production E-bike. You can spend $1,700 on a BionX kit, and $700 on a new hardtail suspension bike, and for $2,400 you will have an electric bike that is probably higher quality than most electric bikes on the market now for the same price.

The BionX Motor


BionX uses a direct-drive (DD, gearless) 350W motor. This limits the moving parts and makes for a robust and reliable set up. The benefits of the direct drive motor include reliability, quietness, and regen braking. The drawbacks are its larger diameter and it’s heavier than a geared hub motor. If you look in the above picture you can see how large the hub motor is in a 26-inch rim. Below is an example of a 350W geared hub-motor (made by Dapu) in a 26-inch wheel of the before mentioned Neo Jumper.

The geared motor is smaller, and stealthier looking. Most  new electric bikes coming out are geared hub motors. So BionX might be a bit behind the times with their big and heavy non-geared motor. To the BionX’s credit, it is thinner than almost any hub motor out there. But when you look at an electric bike, you do not notice how thin the motor is…only how large a diameter it is. The motor in the bike pic below is twice as thick as the BionX, but is super stealth.




The BionX Controller:

bionx controller

All other E-bike kits I know of have controllers with a bunch of wires coming out. The BionX kit on the other hand has an internal controller cleanly built into the hub with the motor (similar to the Golden Motor Magic Pie). This really cuts back on the clutter you see outside the bike, and makes installing this kit much easier. The motor and controller are water resistant and can be ridden in the rain.

The Bionx Dash Board


The BionX has a really sweet dashboard which tells you remaining battery, how fast you are going, how far you have  gone and even what time it is. The dashboard is  custom configurable. In addition, the dashboard controls what level of pedal assist you want, or what level of brake regen you want. Below is a video describing how you can choose levels of pedal assist, and levels of regen using this dashboard:

Cool Throttle


Although the  throttle might seem cheap at first glance. It is actually one of the better throttles I have felt on an electric bike. Most E-bike throttles are cheap China twist or thumb throttles. The BionX throttle is a refreshing change. It is a push button which is variable. So you can push it a little bit to get a little juice. With the 350W motor, this throttle works perfectly. It also has a + and – button above it. This is an alternative way to adjust the pedal assist mode, instead of using buttons on the dashboard. When you are riding the bike it is a real convenience to be able to change the level of assist without your hands leaving the hand grips. For example, when going down a big hill, you can change into a high level of regenerative braking, so you can slow yourself down without wearing or heating up your brake-pads.

The BionX throttle has the extra bonus benefit that it can be used on either the left hand or right hand side. Conventional E-bike throttles can only be used on the right side.

The BionX Battery

The lithium-ion battery of the BionX as of 2012 comes with a two year warranty. It used to be the battery was only warrantied for one year, so my guess is that BionX has improved their battery to be more reliable. Like other high quality E-bike batteries it consists of “18650”-size cells (also found in cordless tools). It is small at 36V / 9-Ah, so you can expect around a 17-mile range under normal riding conditions. The battery that comes in the 48V kit is larger. If you want extra battery, you are stuck buying an extra battery from BionX and figuring out how to mount it to the bike. The BionX is 100%  proprietary, and it is hard to crack if you want to hack it.

Regenerative Braking

A unique function of the BionX kit is very effective regenerative braking system. Regen means that when you are going down a hill, your motor is slowing you down and actually putting energy back into the battery. To activate the regen you simply apply the rear brake lightly…and you feel the drag of the regen kick in. Hit the brake harder and you hear the regular mechanical brake pads of the bicycle kick in. The BionX also has variable regen, which you apply either through the dashboard, or through the handlebar control (the minus button). When  going down a long steep hill, you could apply just the right  amount of regen to cruise down at the speed you want without using your conventional brake. Obviously this adds to the efficiency of the BionX system, and also drastically cuts back on your brake pad wear, and brake heat (very useful if you frequently have long downhills while carrying cargo). Regen braking is always silent and never squeaks.

Read more about regen systems on ebikes

One drawback of a regen system, is that it is said that the bike will not free wheel as effectively, because the motor will always have some drag even when coasting.  On the Bionx bike it seemed to freewheel perfectly when regen was at the lowest setting, and I did not notice any extra drag compared to a regular bike.

Torque Sensor

The BionX has the torque sensor integrated into the motor axle. The BionX patented torque sensor is known to be one of the best  in the industry. Also the BionX software is spot on. This all equates to a really fine pedal assist experience. The BionX does a terrific job of blending electric assist with your pedaling power.

Read our story on torque sensors. 

If you use your torque sensor wisely, the BionX will force you to not to be lazy, and you will always have to input some power if you want electric assist. This will vastly increase your range. The less pedal-assist you use, the farther you will go. If you ride only in the pedal assist mode, the BionX motor comes on so smoothly you can barely feel it. Its easy to forget you are riding on an electric bike when you ride this way, you simply feel like a super athlete when bicycling…




Installing the BionX system on  a bike is fairly straight forward, but BionX does recommend that you have it installed by a qualified shop. The shop I spoke with (Electric Bikes LA) said that it takes an hour and a half for a skilled technician to install a BionX. At a shop rate of $70 an hour that comes to $100 worth of labor to transform a regular bike into electric bike.

BionX Proprietary

The Bionx system is completely integrated. The big drawback to this is if you need to replace a blown controller, blown motor, or bad battery….you are stuck with BionX parts and BionX pricing. This is one of the big drawbacks of BionX.

Hot Rod a BionX?

Many DIYers over at Endless-Sphere started with basic hub conversion kits, and decided that the hub motor was not powerful enough for them. Their are many options for hot rodding a hub motor (see our story).  However hot rodding a BionX (because of the proprietary components) is just not possible. So you will be stuck with a 350W kit, even if you decide later you want to upgrade. This is another drawback to BionX.

Is it fast enough?

This is the core question for me regarding BionX. I live in the USA that has a 750W federal limit on E-bikes (500W in Canada). Anything under 750 watts is definitely considered a bicycle. The BionX is only 350 watts, less than half the wattage of what I am 100%  legally allowed to operate anywhere in the USA.

For me I like my bikes to be at least 750 watts, and most of the time a heck of a lot more (of course I limit my E-bikes to 750W when riding on the street 🙂

Riding the Bionx, it feels very similar to the 250-400 watt production bikes I have ridden. At times I tell myself that it’s fast enough. You can get to 17-MPH or so without pedaling.  It’s when you start climbing hills that you really wish you had a bit more. The bike really slows down to a snails pace on hills.

For me the BionX is not fast enough, especially for the money it costs. I would not personally own a BionX simply for these reasons. To me an expensive and slow E-bike  is a deal killer.

What  I have seen happen many times  is  when  someone first rides an Ebike  they are satisfied with the lower power levels. But as they ride more and get familiar with the E-bike, almost always they wish they had more power. If they get off their bike and ride a faster ebike, then they really want one.

BionX or a no-name kit

BionX kits are 10 steps ahead of every other kit provider out there. Most kit providers are simple box shufflers. BionX has been making and innovating hub motors for nearly 10 years. They have full-time engineers on staff, and are constantly striving to improve their product. It is by far the most reliable hub kit you can buy, easiest to install, smoothest pedal assist and finest user interface.

Although Bionx is a nice solution, it isn’t for everyone.

  • BionX kits are expensive ($1,800 as tested).
  • BionX Kits are low power (350 watts maximum).
  • BionX Kits are proprietary (you can only  use BionX electrical components).

BionX kits do offer big advantages:

  • BionX kits are the most reliable kit on the market.
  • BionX kits are the highest quality kit on the market.
  • BionX comes with a Lithium-Ion battery, most kits do not and if they do…they are usually junk.
  • BionX has figured out how to mount the battery pack.
  • BionX has a finely integrated regen, no other kit has this.
  • BionX offers a two-year warranty and stands behind it.

If you want a high-power kit, and one that is inexpensive,  you have to take your chances elsewhere.

If you are looking for higher power than this, I would recommend kits with Crystalyte, BMC, 9C or MAC motors.  Look at our list of recommended vendors.


If the BionX system is fast enough for you (and you can afford it) it is definitely the most elegant, most complete,  well-built hub motor kit on the market, and that just might be the right kit for you.


Written by Eric, March 2013


Eric has been involved in the electric bike industry since 2002 when he started a 6000 square foot brick and mortar Electric Bike store in downtown San Francisco. He is a true believer that small electric vehicles can change the way we operate and the way we think.