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Hi I saw many people talk about torque arms, woulld some one here explain more about it. By our kit you could see there are 2 washers, is the washer 2 so called torque arm? We always named it washer.

Hi Fusin Tiger,

The picture you attached to your message no longer shows up.

A torque arm is used to reduce the stress placed on the dropouts of a typical fork. The amount of torque produced by the motor is quite strong especially at startup so a torque arm is used to strengthen the dropout and also to distribute the stress further up the fork so that the stress at the dropout is reduced. Here are some dropouts from other companies:

This is the one that www.ebikes.ca sells:
http://ebikes.ca/store/photos/TorqueArm14.jpg

This is the one that www.ampedbikes.com sells:
http://ampedbikes.com/torquearm3.jpg

Here is ampedbikes.com's torque arm installed using the disk brake mounts on the front fork:
http://ampedbikes.com/torquearm1.jpg

The ampedbikes.com torque arm is a bit nicer in that it has an adjustable piece that allows it to be fit on just about any bike with or without the disk brake mount.

Ambrose

Hello Ambrose,

welcome to Fusin Motors.
Just uploaded the photo again, it was lost during the forum update. Wish you will enjoy by our forums.

Thanks.

Hi Fusin Tiger,

Thanks for reposting the photo. I would not call that a torque arm, it's a keyed washer that helps to keep the motor from spinning inside the dropout but it doesn't redistribute the torque from the motor enough to reduce the stress on the dropout.

Ambrose

Hi Ambrose,

thanks for the professional explanation.

We are also developing our own torque arms, should be ready soon.

Thanks.

Here's the Ampedbikes torque arm. I've been using an alloy fork. THIS IS A BAD IDEA. Steel is ideal. I bought the torque arms before I drove the bike even a few miles and they've been installed since day one. Also I constantly check my forks for signs of stress. THIS IS A GOOD IDEA.

we are making a simplified version of this , in 304# stainless steel, also works and low cost.