Ultra low cost torque arm proposal

[currentFlo]

Hi everybody,

I think I'm going to need a torque arm for my rear wheel motor (aluminium fork) because tha axle has started spining after only 3 runs :?
The problem is that everything I see is pretty ugly with clamps etc ...

What do you think about using that kind of spacer as a torque arm:

http://www.crystalyte-europe.com/product.php?productid=16477&cat=299&page=1

It would be glued with DP-420 Epoxy (as doctorbass recommends in his torque arm topic http://www.endless-sphere.com/forums/viewtopic.php?f=31&t=29129&p=420124&hilit=torque+arm#p420124)
http://www.shop3m.com/62328014352.html

Do you think this could be a good idea for a cheap torque arm ?

(ps I can't use doctorbass torque arm solution because there is no room on my rear fork)

Flo

 

[dogman dan]

I would say worth a try for 500 watts or less. We build this big ugly stuff for 3000 watts or more.

Basicly it will do absolutely nothing for you as a torque arm. But they are a dandy device for making the oversize washers fit the alloy QR dropouts on many bikes. Since a good tight nut is all you really need for 500 watts or less it should work for low power hubs, provided you keep your nuts tight. Poor fit is the typical reason they get loose, so you should be ok using the washer an a good tight nut..... For low power.

If you wan to run 48v 20 amps or more, then you are just going to have to get out the steel, a drill, a hacksaw, and a file. Then you can make your own low cost torque arms.

 

[torker]

Only problem I see is the overall diameter is fairly small so it won't "spread" the load much but it is nice and thick which is good.

I see you are fairly new here. Have you searched for the threads about torque arms? Lots of good examples. Welcome btw.

Here is the thread I mentioned http://endless-sphere.com/forums/viewtopic.php?f=2&t=26444&hilit=torque+arms

 

[John in CR]

It has no arm to attach to any point a reasonable distance away from the axle, so it's not a torque arm by any stretch of the imagination.

 

[liveforphysics]

A fine washer, but until you take torque stress off the dropout, its not a torque arm.

 

[dogman dan]

If you held one in your hand, you'd see the above opinions are true. Even if the epoxy did hold real good, it's less strong than a regular steel dropout. Very little metal there.

I do recomend them highly as a washer. They really work great for avoiding the main reason for dropout failure or motor spinout. Which is the nut working loose as misfit washers deform, or oversize washers spreading dropouts. Good tight nuts alone are good for typical kit power, 36v 20 amps. But the nuts must stay tight, with no torque arm.

 

[Spacey]

Nord Lock washers are the washers to use between the main nut and frame, expensive but I have not had one come loose yet.

http://www.nord-lock.com/

 

[currentFlo]

ok thank you for the replies, I finally bought Doctorbass's torque arm, but I'll need to cut it a bit for my frame.

Flo

 

[grindz145]

use two box end wrenches, one on either nut, and crank it down good and hose clamp it, quick, cheap and dirty.

The great Methods has proven this method is 2 lagitt to quit. 8)

 

[liveforphysics]

Nord Lock washers are the washers to use between the main nut and frame, expensive but I have not had one come loose yet.

http://www.nord-lock.com/

Yes. Nord lock are the best fastener locking method out there by a large margin.

 

[SniperGaulois]

i made 2 torque arms at home now, get a strong steel plate 3mm thick, cut it into a slimsine shape for you fork, drill a hole for the axle, machine it to the same of the axle with a file, and attach it to the bike with a cable tie, or drill a second hole in it and screw it to the disc brake hole, takes 1 hours, slim as you like! strong, my one can take 4000 watts of torque at least i would say!