Torque arm?

[Tsakis]

Hi again to all, I am in the prosess of building a new bike and I keep hearing about the torque arm part mainly in front wheal kits...

What exactly a torque arm is?

 

[NRG]

Its a metal bracket that slides over the motor axle and attaches to the the fork leg. The idea is to stop the axle rotating in the dropouts...this can happen if a powerful motor is fitted and the dropouts are not strong enough to prevent it.

 

[Scottyf]

Probably just good practice to use one really just incase.
Obviously dropouts are not designed to take such forces. Although most 250watt motor's will be fine.

I'm currently looking at getting a pair for my bpm motor as its pushing 750watt without to much trouble.

Does anyone out of interest have any measurements of the axel sizes. Least I could get something designed and cut locally. (Else I'll have to find me a verneer and do some measuring)

 

[Cyclezee]

There is a torque arm included in the eZee kit Tsakis

 

[Scottyf]

John do you sell those Seperatly by any chance?

 

[Tsakis]

There is a torque arm included in the eZee kit Tsakis

Nice to read that

 

[Deleted member 4366]

Most kits are supplied with some sort of anti-rotation device - usually anti-rotation washers that clip into the drop-outs. These are all you need for a 250w motor unless you have really thin alloy drop-outs. However, you must make sure that you do up the wheel-nuts tight to hold them in place. My latest bike is running at about 1kw and I'm only using the anti-rotation washers in my alloy frame with no problems so far. I'll let you know if it breaks.

 

[Scottyf]

I am also using the anti rotation washers which should be ok. But I'd rather run something extra as a just incase... As the frame is 6061 Aluminum I just think it would be safer to have something.

 

[aseb]

Front wheel torque arms are different to rear wheel ones- I can't see that you've said which wheel your kit is for. Generally for low power bikes most kit makers don't seem to recommend them on the rear but all do on the front- particularly for aluminium forks.

ebikes.ca have 2 types having discontinued the one shown above (which is probably good for rear wheel drive).
If your forks have lawyers lips then get the spacers too so to wheel gets properly and fully tightened or you could get problems later.

The Grin Cyclery scroll down just over half way.
www.

 

[aseb]

Does anyone out of interest have any measurements of the axel sizes. Least I could get something designed and cut locally. (Else I'll have to find me a verneer and do some measuring)

The flats are 10mm, axle is M12 for the majority of bikes/motors. Crystalyte 5xxx series use a 14mm axle.

 

[Cyclezee]

In the past I have use a modified 'C' spanner as a temporary measure.

If there was enough intrest, I would get some torque arms in from eZee.

The photo below shows an eZee torque arm fitted to my recumbent trike.

Click on image to enlarge it!​

​

 

[Scottyf]

Yeah something like that would be perfect. Just to make sure its got a bit more strength. Since the frame is 6061 aluminium.