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Old 11-17-09, 04:09 PM   #1
1000watt
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Red face Check out the 'play' in this torque arm :(

I bought (2) Torque Arms on ebay for $19.95 Ea. and I test fit them. With the axle nut loosened a little I noticed a considerable amount of play... (torque arm does not fit axle snug enough). Is this normal with most torque arms? I wonder if I should return them? Shouldn't it fit more snug to prevent axle wrap?? I have a 14mm axle.




Also, I have another question: As the tire turns clockwise, does the axle want to wrap/twist counter clockwise?

Last edited by 1000watt; 11-19-09 at 07:05 PM.
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Old 11-17-09, 09:25 PM   #2
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Regarding the rotation of the wheel and affect on the retaining nut... I have been told by motorcycle and snowmobile mechanics that this used to be a concern with retaining bolts and nuts on rotating flywheels and cranks and such to the point that a lot of older engines were made with left handed threads on said bolts and nuts. The principle was that they would not loosen with the rotation of the components. This is not the case in newer engines as most of the issues can be completely compensated for with lock washers and/or "correct" torque wrench settings when installing the bolts or washers. The key there being good engineering and following the service manuals to know the correct torque setting. No such thing on bicycles as far as I know. As long as they are good quality axle bolts/shafts and nuts and NOT ALUMINUM, crank it down as tight as you can get it and you are fine.

I have no experience with the torque arms. I would want as little play as possible myself, however as long as they do keep the motor from spinning in the drop outs they should serve their purpose.
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Old 11-17-09, 11:21 PM   #3
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Quote:
Originally Posted by 1000watt View Post
I bought (2) Torque Arms on ebay for $19.95 Ea. and I test fit them. With the axle nut loosened a little I noticed a considerable amount of play... Is this normal with most torque arms? I wonder if I should return them? Shouldn't it fit more snug to prevent axle wrap?? I have a 14mm axle.




Also, I have another question: As the tire turns clockwise, does the axle want to wrap/twist counter clockwise?
Did you ever fasten the free end that you're playing with in the video to the P-clamp? The P-clamp should hold the torque arm steady. The torque arm you have is similar in design to others. Here's the one sold by e-bikes.ca.



Torque arms are necessary for hub motors since the torque they produce stresses the drop outs and may cause them to fail. (Even steel drop outs can fail.)
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Old 11-20-09, 06:53 AM   #4
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Go to your local hardware store. Bring one of your locking washers. First find a good drill bit that is about 1/8 of an inch smaller then the inside of the washer. Next purchase a peace of flat stock steel. You dont need alot of it just a peace about a foot long. Then purchase a 3 grade A bolts, about 3/4 long, 6 small washers, 3 nylock nuts and some locktight. Lastly you will need a clamp that will take one of your bolts that fits around your frame.

You will need something to cut the flatstock. A hacksaw will do. You will need some cutting oil for your new bits. WD40 works fine. A drill DUH!! Oh and something to tighten it all. A can of decent metal primer helps as well. Lastly you want a round metal file of light or medium coarse grit about 6 inches or longer.

Start by drilling the whole and working it VERY slowly to exactly the shape and size of your axel. It has to be perfect. You should be able to ****e a flashlight on this when its done and see no light coming through your filing job. If its not as tight as possible it will not work. Dont make it so tight you have to beat it on but just right. You want about 3-4 inches on the arm before you cut it. This allows for a great amount of torq. Lastly cut your arm that will attach the peace around the axel to the fram. Its ok if its slightly V shaped. Drill all your wholes for the bolts and clamp it to the frame. Make sure you have at least 2 bolts at the joint that holds both of your peaces together.

Bingo! You made your own torq arm and its probably better then anything you are going to find online.
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Old 11-21-09, 09:17 AM   #5
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hi everyone
that torque arm shown above (http://www.ebike.ca/store/photos/TorqueArm14.jpg), is not meant for rear wheel, and this i know for two reasons:

1. i tried it, horrible horrible
2. ebikes.ca sold it to me and informed me it's not for rear wheel but for front wheel.

What you need to do is get a solid one piece torque arm.

You can either buy it OR you can make it yourself if you're handy with tools: I fashioned one using heavy gauge metal bar from canadian trie, i used a hand held grinder and cutting plate to cut the exact square i needed. It did the job perfectly I have it on my 72 volt 408 cyrstalite system. Careful when using hand held power tools, such as a grinder, you need proper gloves, eye gear, clothes, clamp etc.
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Old 11-26-09, 05:19 PM   #6
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I also tried the ebikes.ca torque arm on my rear Mongoose Blackcomb and it didn't work. The universal ones from ampedbikes.com are generally the best ones for both front and rear and are adjustable in multiple fixed angles. They are also made of EXTREMELY tough metal. Very difficult to drill with my titanium drill bit. Recommended. The ebikes.ca ones are good on the front though, although I have found some forks they don't work with.
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