How many torque arms

[anotherkiwi]

My new build looks to be my current rear motor kit in a bigger, more comfortable 700C frame. I really wanted to put a GSM CD in there but finances being what they are... I thought about running a web campaign but "poor underpaid bloke living in a wonderful part of the world needs funds for sexy e-bike build" does not seem such a great idea...

So how many torque arms does my rear motor need in an aluminium frame?

If one which side do I put it on?

Cheers

Tony

 

[trex]

I reckon you only need torque arms if for motor with 180mm diameter or above. Use a pair, sung fit is important.

 

[Nealh]

My Oxydrive/Bafang CST is on 700C Boardman and I have a home made one piece arm on the disc side albeit the motor is 250w, a bigger watt motor may be better with two to handle the extra torque/power.

 

[anotherkiwi]

Thanks for confirming my thoughts guys. I'll give it a whack with the supplied washers and nice and tight on the nuts. I think that if there is no play i.e. careful on the filing of the dropouts to fit the axle it looks solid enough to take 250 W.

 

[Fordulike]

Thanks for confirming my thoughts guys. I'll give it a whack with the supplied washers and nice and tight on the nuts. I think that if there is no play i.e. careful on the filing of the dropouts to fit the axle it looks solid enough to take 250 W.

I don't want to cast doubt in your mind, but for something that costs a few euros, I would fit at least one torque arm on a low powered set-up.

Probably easiest on the non freewheel/cassette side.

It would lessen any risk of the axle working the nut loose. Even on a low powered motor, there's still a fair amount of rotational force trying to spin that axle in the dropout.

 

[Nealh]

I don't want to cast doubt in your mind, but for something that costs a few euros, I would fit at least one torque arm on a low powered set-up.

Probably easiest on the non freewheel/cassette side.

It would lessen any risk of the axle working the nut loose. Even on a low powered motor, there's still a fair amount of rotational force trying to spin that axle in the dropout.

I have to be in agreeance for safety sake and to prevent any future incidents then 1 is needed on the rear and 2 on a front build with ali forks.

 

[gstanley]

I don't want to cast doubt in your mind, but for something that costs a few euros, I would fit at least one torque arm on a low powered set-up.

Probably easiest on the non freewheel/cassette side.

It would lessen any risk of the axle working the nut loose. Even on a low powered motor, there's still a fair amount of rotational force trying to spin that axle in the dropout.

Sorry to drag up an older thread again, but my left axle nut keeps working itself loose after only a mile, would a torque arm stop this do you think? I have one being delivered this week

 

[Fordulike]

Sorry to drag up an older thread again, but my left axle nut keeps working itself loose after only a mile, would a torque arm stop this do you think? I have one being delivered this week

Most likely yes. The torque arm will help to prevent the slight axle movement that occurs when the drop-out/axle isn't a totally snug fit. This loosens the nut as time goes on.

You've got nothing to lose and everything to gain by fitting a torque arm. Last thing you want is that wheel to pop out while you are riding

 

[Deleted member 4366]

Sorry to drag up an older thread again, but my left axle nut keeps working itself loose after only a mile, would a torque arm stop this do you think? I have one being delivered this week

Is it a direct drive motor with regen?

A torque are would probably help. So would a spring washer.