Torque arm from ebikes.ca

[Russell]

Ok I wasn't going to use a torque arm since I have a low power 250W hub motor but then...well I could not leave well enough alone and I started filing the dropouts some more to see if I could get the axle fruther into the front forks. So of course what WAS a snug fit before with just a little filing is now just a bit looser than I'd like. Therefore I ordered this torque arm from ebikes.ca. From the picture on their website I thought it might work with my fork which has braze-ons for fenders. I received the torque arm today along with some other bits and pieces I had ordered and went about installing it.

Here are the component parts. It's rather small as these things go. It is made from 3.1mm thick stainless steel.
Any idea what the black plastic ring is for?

EDIT: Looks like the black ring is a part for the throttle w/grips that I ordered that got packaged with the torque arm.



After removing the plastic backing the edges could use a bit of light sandpapering to knock down the edge.



Unfortunately the eyelets on my fork interfere with the arm.

View attachment 2

I could mount the long arm to the outside like this but then it slides by the fork instead of touching it.

View attachment 1

Instead I'm using just the bottom section as sort of an anti-rotation washer. The head of the bolt contacts the braze-on and I can attach the fender strut to the bolt.



Not exactly what I had hoped for but it's a bit better than the torque washer that was supplied with the motor.

EDIT:Justin at ebikes pointed out to me that my last arrangement would not work because the axle would torque CW (as viewed from the left side of bike) not CCW as I was thinking therefore the bottom section would rotate AWAY from the eyelet the bolt was in contact with and it would do nothing. I just removed the thing and will have to think of something else.


-R

 

[Russell]

Well after more consideration and after getting some food in my belly I decided on the following configuration...until I can come up with something better.







The position of the top of the torque arm is not ideal, it's off to the side of the fork, but that couldn't be helped. At the very least I'll see about getting a C-clamp to replace the hose clamp.


-R

 

[mn_aerorider1]

Russell - This approach looks much better - After reading your previous post, I was going to recommend you doing exactly what you've done.

Just an additional recommendation - This setup will be especially fail-safe if you can make sure that no rotation occurs at the joint between the short and the long arm: Note that if the arms rotate at this joint, your clamp cannot keep the long arm from sliding in toward the joint and the small arm from rotating during high torque, so if you have not already done so, it would help to add a thin lock washer between the two arms and/or perhaps add some red lock-tite to the joint, and make sure you have a lock washer under your nut, and that the nut is very tight.

Also - I would vote for not replacing the hose clamp with a c-clamp. These hose clamps have been tested many times and found to be strong and reliable by other bikers for other types of torque arms, and they won't fall off - a c-clamp may fall off if it gets loose, unless you have some clever way of mounting it securely.

Just my two cents....

Brian

 

[Russell]

Brian,

Yes you're right the joint is the weak spot, if it slips the arm is no longer a lever. As you can see from the first picture above the torque arm was supplied with a short bolt and a nut but no lockwasher. I substituted a longer bolt and I did place a split lockwasher under the nut. Your idea about adding a thin lockwasher BETWEEN the two pieces may be something I’ll try. I'm assuming you mean something with some bite like a serrated or toothed type lockwasher. I’m not sure however if I’m going to keep this configuration or try something else. The present setup is probably better than the torque washer that was supplied with the motor but I’m not really satisfied with it. I was going to use a torque arm from ampedbikes.com but then I came across this one which I thought might work better with these forks. Oh well this is a hobby and experimentation is part of the fun of it :wink:

-R

 

[mn_aerorider1]

Hi Russell - You're right, the setup you now have is much better than a torque washer. Torque washers are worthless - not enough of a lever arm on them to amount to much, and most are too thin - my torque washers ripped out immediately on my rear wheel 406 hub motor. I am now using 4 torque arms of similar length to yours and because my nut is not all the way on have added a 10" socket wrench held in by a hose clamp. This might sound like overkill to you, but my 3 wheel velo has a reverse and weighs 150 lbs. I have ripped out the power wires 3 times now, and have gradually built up to this multi-torque arm setup.

Brian

 

[ian.mich]

Use dp420 or some strong weld epoxy on the joint between the 2 plates in addition to an m6 with washers and locknuts

 

[motomech]

I use the older style of Ebike CA torque arm and it looks like it would fit better for your application.

 

[Russell]

Guys this is an old thread; that bike has been decommissioned for a while and I didn't use the TA for very long anyway, instead I used mini TA's on both sides bolted to the front braze-ons like so;



The TA was also the first design from ebikes.ca and it's no longer available from them. Knock-offs are available from China and recently I did purchase some for my latest e-bike. The lower pieces are 50% thicker at 4.5mm and work great as torque plates.



-R

 

[ian.mich]

Guys this is an old thread; That bike has been decommissioned for a while and I didn't use the TA for very long anyway, instead I used mini TA's on both sides bolted to the front braze-ons like so;


The TA was also the first design from ebikes.ca and it's no longer available from them. Knock-offs are available from China and recently I did purchase some for my latest e-bike. The lower plates are 50% thicker at 4.5mm and work great as torque plates.


-R

Solid looking, i buy my ripoff ebike-kit torque arms from papamotor http://www.electric-bikekit.com/freewheels-torque-arm/universal-torque-arms-set-of-2-pairs/
buy 4 of them for 17.50 each and sell em to friends. they're 4.5mm as well. Personally i don't like bmsbattery at all.