rim drive "world's lightest" e-bike drive

Using the start up torque reaction to move the motor against the drive surface has been done before by ES member Kepler with his own friction drive. This seems far better than the Rubbee too!
 
I can't stand reading the comments. One guy thinks he has a PhD in bicycle dynamics and he can't even get BREAK vs BRAKE correct. :roll:
 
I don't know of one; I'd guess the major reason not to is that any debris, mud, etc that sticks into the teeth on the rim could easily gum up the works. And if hte motor doesn't have a "suspension" that allows it to ride up over the stuff in the teeth it could just break off teeth on the drive gear, or damage the motor bearings or shaft.
 
PRW-
That was my first thought too. Why not have gearing on the side of the rim? One of the comments did mention using something like a disc brake instead of the rim. You could enclose that to hide the debris. Or why not just use a mid drive like the BBS? Oh well....
 
Also, there's the Cybien drive, which uses an added drive surface:

http://www.cybien.fr/

http://cyclurba.fr/velo/230/cybien-sport-cyclotouriste.html

med_1-%20C3%20Cybien-coursier%20avec%20guidon%20r%E9glable.jpg
 
Tench said:
Using the start up torque reaction to move the motor against the drive surface has been done before by ES member Kepler with his own friction drive. This seems far better than the Rubbee too!

I don't think it use motor torque to engage. It looks to me that it has a cable activation system.

Nice neat design but relatively complicated for a friction drive considering it probably needs 2 speed controllers and an activation system.

Is 4lb light for an RC motor friction drive? I hope that includes battery.
 
I'm with kepler here, it would need to be on the other side of the tube, so the torque kicks it into the rim, and acts to increase the pressure and grip on the hub.

And with a measly little 92wh in the battery, I would hope that 1.6kg is battery inclusive. A 1.6kg drive excluding the battery wouldn't be worth it to only use a 92wh batt. And I can't see it a useable 600 watts, only at high speeds where it isn't really needed? such a small contact area would slip at low speeds surely?
 
bandaro said:
I'm with kepler here, it would need to be on the other side of the tube, so the torque kicks it into the rim, and acts to increase the pressure and grip on the hub.

And with a measly little 92wh in the battery, I would hope that 1.6kg is battery inclusive. A 1.6kg drive excluding the battery wouldn't be worth it to only use a 92wh batt. And I can't see it a useable 600 watts, only at high speeds where it isn't really needed? such a small contact area would slip at low speeds surely?
I think the positioning is correct to increase pressure with torque. The smaller the better, both in diameter and perpendicular thickness of the driving 'wheel' with this type of system. That would have to be some highly engineered friction material for sure, though.

A double pinch on a large diameter hoop-cylinder seems like it would be much easier on the friction material.
 
Actually kind of a neat idea but I don't care for it being driven off the rim. I would personally rather replace a tire once in a while.

I agree that it better have some amazing new, never before seen, friction material on that roller.

As with every other friction drive people have come up with, the big issue will be making sure it can fit on almost any bike. Good luck. With most bikes going to disk brakes these days the options will be even more limited.

With all the press I imagine they will think it's worth $1400 or so like Rubbee which totally defeats the purpose of friction drive.

Friction drive is not new. Pivoting, rim drive, none of them are new. This stuff has been done for years in fact, well over 100 years.
 
Velogical with their Velospeeder rear rim bicycle motor system now on UK website:
http://transportevolved.com/2014/05/21/new-e-bike-kit-lightest-market/

Hehe... "Transport Evolved", the name of that site.
 
http://www.gizmag.com/velological-worlds-lightest-e-bike-drive/31976/
 
Indeed that looks really good.

Perfect for those who want assistance only, but would it assist you where you need it up the really steep stuff ?

I like the way the motors release from the wheel.
 
"The current iteration uses a 92-Wh lithium-polymer battery that provides up to around 12.4 miles (20 km) of e-assist. "

Let's stop sugar coating things and call it what it is:

"The current iteration uses a 92-Wh lithium-polymer battery that provides three and half miles of mediocre performance."
 
Now that is harsh :lol:

I have often used that sized battery on my friction drives (1 x 6S 5ah LiPo) It typically gave me 10km of assist. You tend to leave these types of drives off for much of your ride and only use the assist on inclines. Under these conditions 20km is easy to achieve. Of Course they are not stating riding styles so the average punter is going to presume the drive is constantly on the 20km. This of course is total rubbish.
 
It certainly would be stealthy and rim drive is probably quieter than friction driving the tire.
 
mlt34 said:
"The current iteration uses a 92-Wh lithium-polymer battery that provides up to around 12.4 miles (20 km) of e-assist. "

Let's stop sugar coating things and call it what it is:

"The current iteration uses a 92-Wh lithium-polymer battery that provides three and half miles of mediocre performance."

:D

It's not necessarilly that far off though, if it's more than 80% efficient. I use about 150 Wh to ride 30 km in terrain with lots of hills with my Bafang BBS01 250 W. 92 Wh would get me 18.4 km.
 
Its totally pointless quoting or arguing range on a bicycle assist system .
It all depends on the amount of pedal input the rider applies, the size & weight of the cycle and rider, speed, and the type of terrain traversed.
The only figure that should ever be quoted is the "no pedal" flat ground distance at what ever speed is intended to operate at.
Maybe someone should define some kind of standard setting for a treadmill or bike trainer stand ( resistance , speed, incline etc) that could be used to test ebike drives on. ?
 
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