BionX vs. Crystalyte operation

[EricJ]

This is probably going to become self-evident once I have ridden both types, but I hope someone can describe the difference in operation. I have never even SEEN an ebike and would have to burn 6-10+ gallons of gas to do so. I'm interested in pedal-assist mainly to help me up some local hills pulling a trailer with a recumbent. Here's my understanding of how it works.

With the BionX system, I can set how much pedal-assist I want, the system will sense when I am having to pedal harder than I want to pedal, and will mix in enough power from the motor to bring me to the level of assist I selected.

With a Crystalyte system, I'm a little confused. Some "throttles" seem to just be on/off switches. Is that true? If that is the case, how do I use it for pedal-assist? Do I just turn it on and reduce my own pedalling or even stop pedaling if it goes too fast? Seems like I would be doing a lot of switching on and off.

Other throttles seem to be more proportional like a motorcycle throttle or a potentiometer. In that case, can I just crank in enough power to ease my pedaling effort to a level I am comfortable with? That would make it, more or less, a manual version of the BionX system.

I am leaning towards the Crystalyte systems, obviously because of price. But I've bought enough crap through the years on price that required me to buy TWICE instead of just a little more ONCE so I want to make sure the decision is sensible. I'm also leaning towards the Crystalyte systems because of simplicity. The more sophisticated BionX controller with regen braking and all that means more proprietary things to go wrong and no dealer nearby.

I fly electric RC airplanes with brushless motors and lipo batteries and have 50 years of experience in electronics, so maintaining the Crystalyte system myself is not a problem. I just want to make sure that in actual operation, it is going to do what I need.

Eric

[cerewa]

if you believe several of the crystalyte users over at the endless-sphere.com forums, crystalyte's quality is superb. Those guys say if you buy their high-powered controllers, the 40x series motors are actually strong enough for something like 2000 watts (~3 horsepower) of power.

The throttles work just like you expect a throttle to work-- by changing the position of the throttle you can get any desired percentage of the motor's full power.

Due to the throttle, you get to decide whether or not you want to pedal at all if you have a standard crystalyte setup.

[EricJ]

Thanks, Cerewa. I was hoping that's how it would work. All that proprietary microprocessor controlled gee whiz stuff in the BionX worries me. It's great when it's working. It's not so great when it inevitably fails. Given the price of the Crystalyte kits, I can afford to have a spare controller around, and I can make up my own battery packs.

Eric

[Abneycat]

Eric, Cerewa is accurate on the throttle. Its not just on/off, its variable, just like that you would get on a motorcycle.

As far as maintenance is concerned, if you don't abuse the system (indecent weather exposure, careless overvolting, bombing off big objects), Crystalyte and BionX need exactly:
Nothing.

Seriously. The system is entirely self contained and aside from the typical cleaning and care you'd do for a normal wheel, brushless hub motors need absolutely nothing, and won't suffer from neglect at all. You know, don't do anything silly like letting your axle rust, but they don't need to be babied, which is nice.

And as for a comparison between the two, well..

Crystalyte isn't crap, so I wouldn't worry about that being a concern. Their systems are of excellent reliability and good performance. They aren't light weight or flashy, and don't come with extras. These are workhorses, they do the one thing, they do it well. Not likely to break down, but if they do, Crystalyte is very open to modification, repair, and parts replacement - and parts can be found *quite* easily. This is an excellent choice if the weight isn't going to get you down.

BionX kits are considerably lighter, some of them weigh in *total* what the hub on the Crystalyte does alone. They're also quite fully featured, as you've probably noticed. They perform well, pedal assist is nice, and the kits are of a very polished feel. However, the parts are all proprietary, including the battery packs and such.

[EricJ]

I appreciate the comments from both of you. I mentioned to you in another thread that I want to put a front hub motor on my RANS V2. But a couple of things have changed that. One, I have decided to sell the V2. Second, my mom recently broke her hip. She is 85 and an avid walker. Up until recently, she walked 2 miles a day. She also has a neurological disease that makes it difficult for her to feel her feet so she tends to trip at times since she can't tell if she has lifted her foot enough to clear variations in her path. She lives in a retirement community that is dead flat. So I'm thinking an electrified adult trike would be a good way for her to get around and get some needed exercise, but have the motor assist as well. So that is probably going to be the project bike instead of the V2. All the same requirements and needs are still pretty much the same, though the specs will differ a little since the front wheel will be larger. And if she doesn't like it, I'll keep it as a grocery hauler!

Thanks again, both of you, for the valuable information.

Eric

[treknavigator]

bion x really is a less weight system every pound of weight off is like gold when your riding