3 Mistakes in Ebike Purchases

Finding an ebike or kit can be a challenge in today’s environment. Everyone claims their kits and bikes are great, but how do you really know? If you research ebike kits on popular forums, like endless-sphere or V is for Voltage, you’ll get a wide variety of opinions, often conflicting. These forums are great and have a lot of useful information, but trying to sort the wheat from the chaff, so to speak, can be a real challenge!

When I was researching electric kits, I know how much work it took and how difficult it was to know who to trust. That’s why I decided to have an open door policy on questions, and make sure we provided the best information and answers we could, not just representing one vendor or brand of ebike or kit. I’ve had people ask all kinds of questions, both people buying their first kits, as well as those buying a second or third kit. Here are 3 common mistakes or misconceptions I’ve found many people to have.

1. Putting a front motor on a suspension fork

This is usually a big mistake. Most suspension forks are made out of cast aluminum materials. The aluminum is strong, but not flexible, and can be brittle. A rotating front hub motor puts a lot of stress at the fork dropout – the little U shapes in the fork that hold the wheel to the fork. Under this kind of stress, the drop outs can crack and break, causing your wheel to no longer be attached to your bike. You can imagine the consequences of this, especially if it occurs at high speed. If you are thinking of converting a bike with front suspension forks, it is recommended to go with a rear wheel motor.

Fortunately, steel is a more flexible material and less likely to break under stress. So putting a front motor on a steel fork is perfectly acceptable. I recommended adding a torque arm to these forks, which translates some of the rotational force to the fork arm, and not just the drop-out. With a steel fork, torque arm, and proper installation, a front motor is often a great solution, and results in a bike with “all wheel drive”.

2. Assuming a pre-built electric bike is higher quality than an electric kit

Many people in the market for electric bikes often assume that a bike that is made as an electric bike at the factory will be superior to an electric conversion kit. While ebikes are great solutions for some people (which is why we carry them), for some people, an electric kit could be the best.

The main differences between ebikes and ebike kits are in performance and style. Ebikes have the advantage of being designed around the electric system, so often come with built-in battery compartments, and low-profile, stylish designs. The ebike kits, however, are not integrated into your bike, so batteries are often carried on a rear rack in a pannier or bag, which some people don’t like, and there is additional wiring to run along your frame. One exception is the Bionx kit, which is well designed to fit very cleanly and look great on bikes with a triangular frame.

Another main difference between ebikes and ebike kits is in performance. Because ebikes are sold as a complete unit, they are often powered on the low end to comply with any potential laws about bike speed, and also to protect the companies from a liability perspective. Most ebikes top out at 15-18mph and provide pedaling assistance on hills, but won’t be able to propel you and the bike uphill on their own. Many riders can achieve 15-18mph under their own power, so the electric assist only helps on hills. (Sometimes that is all we need!). Ebike kits, however, are often higher power. Many of them have a top speed of 20-30mph, and have more climbing power. These kits are better performing for the rider who is looking for speed or who is carrying a heavy load.

And lastly, for some of the less expensive pre-built ebikes, the non-electric bike components are often of low quality, just like you would have on inexpensive regular bikes. This might be fine for the user who only rides the bike occasionally, but if you’re planning on using the bike regularly, you don’t want to pay a lot of money for a bike, only to have it start breaking and having to have parts replaced after a year of use. If you are in the market for an ebike, make sure you check out the bike component quality as well as the electric system, and be prepared to pay a little more to get something quality. Or consider converting a quality non-electric bike  using a conversion kit.

3. Buying a kit that is overpowered

Because most people do not have a chance to ride an ebike or ebike kit before purchasing, I find that many people want to get the highest powered kit that is available. When you aren’t sure if you can get up that particular hill you have in mind (which might be steep or long), it is natural to want to get the most powerful kit to ensure you have enough oomph. However, in many cases, the most powerful kit is overkill and you end up spending too much money and carrying around more battery or motor weight that is necessary.

An illustration of this phenomenon is what we saw with our BMC motors. First, BMC had a V1 motor (a “400watt ” motor) which is internally geared and has great hill climbing ability. Compared to pedaling up a hill without a motor, the V1 makes it so you can pedal moderately, as you would on the flats, and still climb up the hill. This was great and many people were excited.

Then along came the V2 motor, which was even higher powered (“600W”). This motor is for people who want high speed or high torque applications. It’s main advantage is being able to handle more power. This was fabulous and everyone thought it was “top of the line” and the best motor for xyz. The high speed motor is capable of speeds over 30mph even (that’s FAST for  a bike). Everyone was happy until…

BMC comes out with the V3 motor, which is supposed to be a 1000W motor. Now everyone is asking about this motor – is it better than the V2? Is that what I need? The problem with these higher powered motors is that in order to take advantage of the extra power, you need a BIG battery. Because they tend to be battery hogs. And big batteries are pricey and can be heavy.  And most batteries simply don’t last as long when putting out the high currents needed by these high-power motors.

By all means, if you are looking for very high speed, carrying a cargo trailer with 500 lbs of gear, or climbing 30%+ grades, then go for a high powered motor that can handle these applications. But if you are commuting with yourself and a 20lb briefcase, then you might not need to fork out that extra dough. The standard eZee kit at 36V, for example, is an incredible performer, and will easily tackle just about any hill, even on loaded cargo bikes, and is relatively lightweight. If you compare it to riding your bike unassisted, you’ll be blown away by its performance. (If you compare it to a sports car, however…well then you might be disappointed. )

If you have a chance to ride an ebike or ebike kit before purchasing, that is by far the best way to get a feel for performance. If there is no store in your area carrying ebikes, check out some of those forums (endless sphere, V is for Voltage)  and see if there is an ebike enthusiast in your area that might offer a test ride.

10 thoughts

  1. Let me know when a compatible kit comes in for my Giant Cyprus Comfort bike.
    I left my name and number with the sales person.

  2. Thank you Elise for all your dedication to educate all of us. Hope your break was resting and rejuvenating!

  3. The first two points make sense, but I completely disagree with the third point about buying a kit that is overpowered. There isn’t an ebike or kit made that is over-powered, in fact, they are all underpowered, including the BMC V3 which I use running at 48v lithium. You need all the power you can get to keep up with traffic on busy streets and for hill climbing ability where ebikes really suffer. Keep in mind, even a BMC V3 running at the recommended 35-40 amps is only about 2.5 horsepower.

  4. I completely agree with these points & thanks for putting some clarity into the mess this industry is becoming. Not only do big powerful motors require big heavy batteries, they put additional stresses on the frames which therefore require to be substantially stronger to cope with the extra weight & forces being applied. For most people intending to ride a bike like a bike a little power assist is all that is needed. If you require 2 or 3 horsepower for your ride then by all accounts you should be looking at an electric motorcycle.

  5. Yes! I have seen a few people riding around town on bikes that have an added lawnmower engine, and they’re never pedaling. I think to myself: why not just get a scooter then? The point of an e-bike is to use at least some leg power in the mix! Anyway, thanks for dropping by!

  6. Morgan why are you Harding I have been using an ebike for five years. I use it for work for going to the store since I have had back surgery it is perfect for me. Where I live Southern Cali. Lapd loves stopping people on motorized bikes and impounding them especially African Americans so since I have been on the ebike they still stop me but they get upset because in my state they are street legal thanks ebike.

  7. Another point to make is buying a rear wheel kit and applying the huge weight of a battery on a cargo rack on the same bike, above the wheel. So much weight and pressure on the wheel including your body weight, eventually the wheel hub buckles. Maybe casted wheels fare better. Someone needs to point this issue out. I suffered after buying a rear wheel for the spokes to go wobbly after only 50 miles riding.

  8. Thanks for sharing this valuable content. I will always remember this. You have mentioned all technical specs of BMC motors.

  9. Halp! I believe my rear bike forks are too narrow to get the full e-wheel on-between. It’s just a regular mountain bike and I spent a bunch of money on the kit already, is there anything I can do or am I burnt?

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