Torque Arm For X5 Rear Motor

[ngocthach1130]

most bikes have different rear dropout so your torque arm would need to be custom makes. Or if your bike is a common bike which someone have used before, then they might have suggestion. If not you can take a picture of your rear dropout and maybe someone is willing to machine one for you. Chance are, you'll still have to draw a paper mock up of the torque arm.

 

[Microbatman]

Great idea

Will work on mock up next and post picture and dimensions.

 

[Doctorbass]

Looking for Torque arm for X5304 Rear motor

Anyone have any?

Will pay/send paypal

I am in United States Ohio

A cheap "TORQUE ARM" is to use this: !! (it work well on a 5305 at 3800Watts)

a 21mm hex key !! cheap, very strong easy to install

Doc

 

[Ypedal]

Doc . That idea works at keeping the axle nuts tight.. but i don't see this method working well at supporting the axle itself and preventing your dropouts from widening !?

 

[CGameProgrammer]

The axle nut is threaded onto the axle itself, so if the nut does not spin, the axle cannot either. Doc's idea is clever, but it means the torque will be applied to the threads of the axle, which isn't great. Maybe it works though.

There'd also be a risk of the axle nut simply sliding outwards but a second axle nut or some locking mechanisms (red loctite perhaps) would resist this. Hm... maybe I'll have to do this myself.

 

[kbarrett]

Hmmm .... would axle torque rotation cause that setup to tighten, or loosen?

I think it would loosen it, yes? Torque force is in the direction opposite wheel spin?

If so, then that rig would not function as planned, I think.

Of course, using the box ends to prevent the nuts from loosening due to vibration would prevent it from getting loose enough to start spinning in the first place. Yea, it would work, but it isn't optimum.

 

[kbarrett]

The notion of just fitting a really long 10mm wrench on that flat, and then TIG welding the sucker in place permanently onto the axle is getting more and more attractive ....

( edit: the wrench would have to be INSIDE the dropouts with the hub itself ... kinda hard to tighten if it gets welded outside .... heh )

 

[Microbatman]

Here is the best I have found using the 10mm wrench idea.

http://buy1beta.snapon.com/catalog/item.asp?item_ID=5176&group_ID=558


http://www.sears.com/shc/s/p_10153_12605_00986351000P?vName=Tools&cName=HandTools,GeneralPurpose&sName=Wrenches&psid=FROOGLE01&sid=IDx20070921x00003a


Check out the angle.
Might work!!

I am going to give the one at sears a try an post results.

 

[Link]

Hmmm .... would axle torque rotation cause that setup to tighten, or loosen?

*messes with pencil*

Depends on which side you put it on.

The side that Doc is showing gets looser (but not much, because it still can't really spin) and the other side gets tighter.

 

[kbarrett]

Hmmm .... would axle torque rotation cause that setup to tighten, or loosen?

*messes with pencil*

Depends on which side you put it on.

The side that Doc is showing gets looser (but not much, because it still can't really spin) and the other side gets tighter.

OK then,it will work. Left side simply keeps the nut from wandering out from vibration. Right side will actually tighten up under torque stress. Looks like the right side box end is doing most of the work there.

 

[kbarrett]

Check out the angle.
Might work!!

I am going to give the one at sears a try an post results.

You might have to use an acetylene torch to put a bend in the middle of it ... not a big deal. It looks like Doc Basses box end thingie will also work on the right side.

 

[CGameProgrammer]

This is turning into a massive derail that belongs in e-bike technical but whatever.

For the nut on the left, the axle will try to rotate clockwise while the spanner / box-end wrench keeps the nut still. If the axle rotates then the nut will simply loosen. Remember that there are two ways of removing the nut: rotate the nut counter-clockwise, or rotate the axle clockwise. Either one works equally well! So the best way to think of this is to imagine the motor's torque applying a counter-clockwise rotation to the nut itself (with no wrench on it). You will need a locking mechanism strong enough to prevent this. Things that might help are loctite, locknuts, cotter pins (best idea, probably, but involves drilling a hole in the axle).

Of course the right side, as mentioned, would cause the nut to move inward, not outward, which is obviously difficult, but not impossible. Remember, even when you get the nut very tightly on, you can usually still get it on a little bit more, or use a longer wrench to make it easier to turn it more. And if you can do that, the axle can rotate by that same amount! So you'd still need a good locking mechanism.

 

[Link]

Eh. Even if the motor manages to shear the threading off of something (nearly impossible) or rotate inside the drops, the wrenches will still keep the wheel in place if they're attached well. Much better than having the wheel fall off, IMO.

Besides, if it works on the Doc's crazy setup, it'll definitely work on most of ours :wink:.

 

[CGameProgrammer]

The problem isn't that the wheel could fall off; it's that if the axle rotates even a bit, the dropouts will be widened, ruining the frame. And in particular, as it rotates it will yank on the wire. If there's not enough slack or if the axle spins around alot, shorts can occur that destroy the motor and/or controller.

 

[Link]

True, but good lock washers/nuts will help keep the drops in place. Wrenches on them to keep them from spinning means they stay tight.

And if your drops do fail, find a better frame.

Too bad the S-series bikes have aluminum rear triangles. 8mm of steel would make a really formidable drop.

 

[Doctorbass]

the wrenches will still keep the wheel in place if they're attached well. Much better than having the wheel fall off, IMO.

Besides, if it works on the Doc's crazy setup, it'll definitely work on most of ours :wink:.

Effectively, that was one of the goal!

When i installed them, the first reason was to re-enforce the little frame tuves on the rear and to keep the wheel on the bike if any drop would broke and that would avoid to rip the wires and all trouble that make...

I can ensure you that the nuts are so tighten thani think i would need an impact to unscrew those!!

That began a day where i just drove on a train track .. with alot of vibrations due to the multiple bumps on the track.

When i came back to my house, i was just curious and checked these nuts... I was very surprized to see that my own hand was able to rotate it on the left side !! the right side was untightened to....

From now, i've never had any problem anyway if the motor can apply 4600lbs shared on each bolt flat and the side of each nuts...

Doc

 

[Microbatman]

Eh. Even if the motor manages to shear the threading off of something (nearly impossible) or rotate inside the drops, the wrenches will still keep the wheel in place if they're attached well. Much better than having the wheel fall off, IMO.

Besides, if it works on the Doc's crazy setup, it'll definitely work on most of ours :wink:.

How much torque (approximately) can these treads handle before stripping using the method Doc mentioned?

Or

IF f I drill it out and use a cotter pin or 3mm hardened steel solid metal pin.
How much torque could the pin handle before failing?

I like the idea of putting a hex nut on the end with a wrench. I would favor the method of drilling a hole through the nut and axel to keep it from rotating vs relying on the threads.

Maybe a combination of a pin approch and a reverse treaded bolt will do the trick.

 

[Link]

How much torque (approximately) can these treads handle before stripping using the method Doc mentioned?

I could work it out, but I don't know anything about the measurements or material grade on even my hub motor's axle, and it'll be different for different hubs.

http://www.roymech.co.uk/Useful_Tables/Screws/Thread_Calcs.html

Have fun .

 

[kbarrett]

I'm asking the admins to move this threadjack of ours to e-bike technical, and maybe preserve the original poster's WTB post.

 

[Link]

I'm asking the admins to move this threadjack of ours to e-bike technical, and maybe preserve the original poster's WTB post.

+1

 

[Microbatman]

Sounds good to me
Move it
No objections

 

[knightmb]

Done!

 

[lazarus2405]

And now I've found it. Sweet. Thanks, knightmb!

Okay, so I have a torque arm that Jonathan on these forums machined for me, specifically for the S-series bikes. It fits beautifully, and does the job.

However, since I switched frames, and since the S-series dropouts are very peculiar, the arm doesn't fit too well, but with some creative rearrangement it can fit and hold motor torque (but not regen).

The bit clamping on the axle is stainless steel, while the rest of the arm is 6061. The two pieces screw together, which is the only reason I could use it on my new frame: the thing can be put together backwards or upside-down or both.

And it installed on the XTS:

To get it to fit, the It looks better on the S25 frame, but I don't have a pic of it. :|

I, also, am using a wrench on the other side. In this direction it holds the torque through the threads. The zip strips are temporary, as is the adjustable wrench. I'll upgrade that to something that won't loosen.

 

[RLT]

Of all the things done on my Project #1MK1 this was by far the easiest.
5 minutes with a propane torch (didn't even have to wheel out the OxyAcetylene) a vise, a hammer and a piece of pipe to use as a handle.
5 minutes with a electric welder (I used MIG, a cheap little AC 'buzz box will do)... or just use a screw clamp.

Put them inside if you have the space, outside if not.

Just make sure to keep the open end part as cool as possible, so you don't lose the temper of the part that will hold the axle. I used some thick aluminum plates on the vise jaws as heat sinks and put a wet rag on it.

Oh, ignore the text in green on the photo about it being structurally useless... That is because I was using torque plates as well:

 

[Link]

Nice. Might try a variation on that (bend the wrench and attach with hose clamps instead of permanent welding).