wizardofozzz wrote:I have a few questions about the Bionx kits (specifically I'm looking at the 250 rear kit).
I'll try to answer your questions. I am a Bionx
customer, and have about 4500 miles on a PL350 that is just over a year old. I am an engineer, too, and have no other relationship with Bionx
1. I thought I could perhaps buy it without a battery and have my husband, who is an engineer, make a cheap yet light battery for me. But apparently BionX systems require that you use their battery. Why do you have to use the BionX battery? I need specifics that my husband will understand.
This is a hard one to answer simply. The Bionx
throttle/readout/user controller, what Bionx
calls the controller, is very sophisticated, useful, and well built. Most ebikes have an on/off switch (often part of the battery
pack), a twist or thumb throttle, a brake lever sense switch (to cut power when braking), and a multi-LED battery
charge indicator. The Bionx
controller includes the on/off switch, power adjust switch, speedometer, odometer/trip/timer/clock multifunction readout, multi-segment battery
charge indicator, and a power demand indicator that shows assist or regen amount. The brake switch plugs into this controller, and this controller plugs into the battery
. This controller is also used to set many programmable values in the system (such as pedal assist sensitivity, regen rate, wheel size for speedo calibration, etc.).
Where most ebikes have an external power controller which switches the battery
current to the motor windings, and contains the electronics necessary to properly time the power controller for the motor control, Bionx
puts the controller inside the motor housing, but has some of the electronics inside the battery
, along with battery
protection circuitry. The division of electronics between the throttle controller, motor controller, and battery
protection is unusual, has advantages for Bionx
. It also makes it incompatible with most other systems. I can only speculate why Bionx
is designed this way, and some will say it is to prevent customers from using non-Bionx
batteries, but I can think of various engineering advantages consistent with the rest of the apparent Bionx
goals for the best ebike solution that would dictate the division of electronics like Bionx
2. Do any other kits have this pedal assist feature? What about a hack? Can you turn an ampedbike or ebikekit into a pedal assist (not cruise control)? If so, how?
I believe most companies call this pedelec, and I also believe it is the only kind of system that is legal in many european countries. Trek is packaging the Bionx
system on three models of their bikes, and charging more than full retail of the base bike and the base Bionx
system that they are integrating. It looks like they have added a few "body" pieces to hide the wiring. Other companies also sell pedelec type ebikes in the US. Giant and Schwinn are two that I've seen in my LBS. Pedelec is usually done with a torque sensor inside the motor housing on a rear hub system like Bionx
, or with a torque sensor inside the pedal bearings on front hub systems like Giant and Schwinn. I can say that the Bionx
pedelec works great, and I rarely use the throttle. Most systems offer one or the other, while Bionx
3. Is the BionX kit really worth paying so much extra for? Is it that much better than a simple throttle system? I don't care about the regenerative braking. I just really liked the pedal assist feature, but mabe it's almost the same to use a thumb throttle.
I think the Bionx
is excellent, and not a bad value. It is designed well, well made, works great, and is a quality system. There are more expensive systems on the market that I think are not as well made or designed, or as complete of package as the Bionx
does not offer anything low-end. I have ridden inexpensive systems that work well, and there are many ways to save money over the Bionx
systems, but I also think there is quality and value in the Bionx
kits. I would say it is a bit like the difference between a Toyota Camry, and the $7000 more expensive Lexus ES. There is value in the ES, but you have to pay to get the extras. If you want the extras, you are unlikely to find it as cheap anywhere else. If you want loads more power, or more speed, or something else Bionx
does not offer, you will have to pay well for that, too.
Like you, I was not really interested in the regen. However, I now LOVE the "power" brakes! About 80% of my braking is regen only, and it is addictive, much like power brakes in a car are addictive (if you are old enough to have driven a car without power brakes, you will know what I mean!).