Axle wires are twisting---why?

medusa569

100 W
Joined
Sep 17, 2010
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161
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Washington DC
After breaking a couple of hall sensors wires in a bad puller incident I had to rewire the hall sensors with a slightly larger wire.
The phase wires remained the original . It took some doing but finally got all the wires pulled through the axle to extrude them out the axle side. I had accidentally flared s the end of the axle so had to cut off a little bit of it 1/4-1/2 ". Put it all back on the bike and have ridden it some for the last 3 days but it seems occasionally the wires are twisting up and causing me problems and its a wonder they haven't been torn up. why are the wires twisting?? I though they pretty much remained motionless inside the axle so whats up with this stuff?? the axle itself doesn't move..just the wires. help please.....
 
Ypedal said:
if the axle is not spinning in the fork/frame, then the stator is spinning on the axle.

what type of motor .. DD or geared ?


I have an ezee geared motor. The axle is not spinning as the torque arm is holding . The torque arm is on the other side of the fork. There is no wiggle room at all. A pic of the shortened axle is attached. Should I perhaps have the wires taped up and extending out so they don't catch on the sides of the axle??
 

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so where is it twisting? why did you decide to use larger wires for the hall sensors? you could not fine the regular smaller wires? it doesn't look like a twist off in that picture so maybe the wires are just moving around under the pressure of so much wire being jammed into the hole that it has to move to relieve the pressure of the knot inside the axle.
 
You can see the circular pattern of the wires as they have already twisted around a couple of times. I used the larger gauge wire as it was all I had on hand and to use the smaller wire would have needed more tools to accomodate that I don't have. Frankly i like the larger ones as well for their sturdiness compared to the 24 gauge. While the wires are snug I didn't think that was a problem. There should be no knot if the axle doesn't turn and the wires as well should remain stationary.
Maybe I'll try and make a clip of the wheel in action....which will be hard for one person..but I'll see what I can do.
 
so that was not how you left it when you finished?

it does appear they are twisted in the reverse direction of rotation of the wheel so it must be moving inside if the torque arm is not slipping.

i woulda thought the motor was fixed by splines inside to prevent it from rotating like that though. so maybe gaston is right about the stator moving.
 
dnmun said:
so that was not how you left it when you finished?

it does appear they are twisted in the reverse direction of rotation of the wheel so it must be moving inside if the torque arm is not slipping.

i woulda thought the motor was fixed by splines inside to prevent it from rotating like that though. so maybe gaston is right about the stator moving.


No the wires looked like most motors straight out with a slight curve to the left to adhere to the rack or fork leg. I just didn't zip tie it yet. The curlycue look came from a couple of times when the bike would stop out of the blue while riding and I looked down and saw the wires twisted around the square metal piece that is offered to protect the axle end . Thankfully it wasn't enough to do sever damage to the wires yet but I was perplexed as to why this was happening. While I did notice one of the nuts loosening up the axle didn't turn because of the brace on the other fork leg. I took off that protective piece to allow more freedom for the wires now. Why would the stator be occasionally be turning. Remember that I have riding this now since the rewire for about 3 days and this has happened only about 3 times but I want to nip it in the bud before I do tear off my wires.
 
if the axle is not turning then it has to be the stator like he said.

you should take it off again and inspect the torque arm slot to see if it has been gouged open by the axle and look inside the motor to see if you can find how the stator would be able to turn, and evidence that it did.

that seems like the only two ways it could happen. if the stator is turning inside you can try to clean it up with solvent and epoxy it to the axle. or take it to a muffler shop and have the guy weld the stator to the axle. it would only need a small spot weld to hold it.
 
Problem found....it WAS the axle turning albeit every now and then. At least one of the nuts must have loosened up and allowed the axle to spin but what I don't understand is why the torque arm didn't hold it.? That's what its supposed to be for. It chewed out the aluminum arm like butter. I have the universal torque arm. Gotta find one made of steel if possible. A waste of $25.00
 
Just make sure the torque arm is as thick as possible (5mm or more if you have the axle length to spare) and that it fits *exactly*, to the point it's kinda not easy to put onto the axle, and that the axle hole is not longer than the axle's diameter.

If it is able to rock back and forth on the axle, then just like a wrong-size wrench on a nut, it'll just slip around it and strip the corners off the axle itself if it is harder than the axle, or gouge out the torque arm if the axle is harder.

If there is enough (any, really) extra length on the rounded axle end parts of the hole in teh torque arm, then the thinner part over the flats can be levered outward by the axle as it turns, and the same thing can happen as above.

If the torque arm is thin but hard, it will cut into the axle; if thin and soft the axle will cut into it. The thicker it is, the more surface area in contact with the flats of the axle, and the less likely it is to come loose.

You're better off with a torque arm just a hair softer than the axle so that if something has to give, it's the part you can replace. ;)
 
OK so I go riding again to test whether I licked the problem of spinning wires and front axle. I didn't... but then again I was trying to use the same distorted torque arm which must be the only thing holding the axle in snugly ( or used to ) as the fork is big enough to allow the spinning but too small for c washers to take up the slack. I had the nuts torqued really tight too but that didn't help. I break it down today and start to restrategize and notice on my first broken down motor ( 9C ) that there sits gleaming at me is another torque arms . Oh joy..I cannabalism the part to place on my current motor and notice the difference in the arms. No they are not all made alike . You can see the distortion on the broken one that didn't hold the axle.
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I also notice the differences in construction. The older one ( aluminum ?) is thinner 5mm vs 6mm. The length on the older one is longer than the other 3" vs 3 1/2" .
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Not that it would have functional difference but merely as a form of identifying one make from another. Given the play in the fork size vs axle I decided to try and use a c washer as a spacer and was working on the non wired side of fork when I noticed significant stripping of the axle. Is there any tricks around this one to help assure a solid set and nut or do I ( can I ) replace the axle??
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thanks for all your input. I'd hate to have to spend out more big $$$ on another motor.
 

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A lug nut for a car has more threads in it than a standard nut does.
Find one of the right diameter and pitch maybe add a washer or two under it and good luck.
 
That's the problme I was talking about.

As said above, you can use a nut that's "longer", or you can stack washers over the stripped area, or both.

Problem is torque arms won't grip that area as well anymore, either.

But torque arms that have already failed to hold are no longer going to do so and need to be replaced, if they are damaged where they can slip around the axle--they aren't doing anything anymore once they reach taht point.


The axle can be replaced in any motor, but it may require special equipment--presses, cutting and welding, knurling, etc. Depends on how they made your motor. Best bet if you want to do that is to poke around the forums for other axle replacements, and see if any of them look like your motor does inside (or if they are the same model).


(note: I moved your new thread into your original one about the problem so people that were already helping you can continue to do so; it's much better to keep posting in a single thread about a problem until it's resolved, rather than start new trheads for it).
 
can you get a steel torque arm inside the dropout so it will act on undamaged section of the axle? are they all aluminum? do you have hard steel ones that will go inside?

i am not sure what you are talking about when you are saying C-washer because i never saw one. the nut has to be snug on the threads when you turn it, not loose. if the nut is lose on the threads you have to find another nut that is tighter on the threads. and don't over torque since it is only half threads since most of the metal is missing.
 
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dnmun said:
can you get a steel torque arm inside the dropout so it will act on undamaged section of the axle? are they all aluminum? do you have hard steel ones that will go inside?

i am not sure what you are talking about when you are saying C-washer because i never saw one. the nut has to be snug on the threads when you turn it, not loose. if the nut is lose on the threads you have to find another nut that is tighter on the threads. and don't over torque since it is only half threads since most of the metal is missing.

I read that steel ones are available and allegedly the one I bought from Justin is supposed to be steel on the component that sits on the axle ( the part that got chewed) . A c washer is shaped like a c and is used to fill up the space difference between drop outs and axles sizes...ebk-c-wshr.jpg In my case I plan to use it in lieu of the spacer since it has that tight fit around the axle. The nut was tight when I mounted it the second time..but still I had torque shake it loose. Now I see the stripped axle.
 
Unless I see it wrong, that's a 12 mm axle. With shorter flats on them, they can chew out the axle, the arm or both and rotate. I've come to prefer 14mm axles for sure.

Letting the nuts get loose didn't help any, but once the axle strips you can't get them near as tight anymore. If you can't figure out a pinch dropout solution, the next thing to try is having a torque arm made, or modified to fit tighter, along with new nuts positioned so they grab the remaining good threads.
 
OK so I have no space to put the new torque arm close to the drop put because there's only about 3mm threads because of the lawyers lips and I need to put spacer there ( I'd rather not loose the lips - these forks look pretty thin if I do file them down) . Is the steel c washer ok to use as spacer? c washer spacer.jpg Going past the stripped threads I have remaining only 6mm of good threads again on the end of axle. The arm is 6 MM in width which would leave only 3mm for the nut...which seems too small for my taste. I slipped the new arm over the damaged area and it still looks like a good fit and I can pile up some washers after that until nut has some good threads to bite into. Any comments on this new build??
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dogman said:
Unless I see it wrong, that's a 12 mm axle. With shorter flats on them, they can chew out the axle, the arm or both and rotate. I've come to prefer 14mm axles for sure.

Letting the nuts get loose didn't help any, but once the axle strips you can't get them near as tight anymore. If you can't figure out a pinch dropout solution, the next thing to try is having a torque arm made, or modified to fit tighter, along with new nuts positioned so they grab the remaining good threads.

The axle measures 10mm flat to flat side and 12mm round to round. What is a pinch drop out??
 
medusa569 said:
dogman said:
Unless I see it wrong, that's a 12 mm axle. With shorter flats on them, they can chew out the axle, the arm or both and rotate. I've come to prefer 14mm axles for sure.

Letting the nuts get loose didn't help any, but once the axle strips you can't get them near as tight anymore. If you can't figure out a pinch dropout solution, the next thing to try is having a torque arm made, or modified to fit tighter, along with new nuts positioned so they grab the remaining good threads.

The axle measures 10mm flat to flat side and 12mm round to round. What is a pinch drop out??

That's your cause for failure right there. Did you notice the axle sloppy in the torque arm when you assembled it?

You've gotta bad problem and don't appear to have the mechanical skills to address it. You need to find somebody who knows how to wrench. A pinch dropout clamps the axle - there are many examples around here. Try search and if that doesn't work we can spoon feed you.

Unfortunately, if you didn't catch the 12mm-14mm axle difference and went with what you've done, you probably don't have much business fabricating pinch dropout torque arms. This is no joke - this is your front wheel and your LIFE you're taking chances with.
 
A pinch dropout is a clamping torque arm.

Here's my version on a rear motor.mongoose pinch dropout.JPG
 
The long nut thing can be a temporary solution if you also use the outer hex as your new torque arm base. If you look at the front wheel as it will rotate forward clockwise (right side), the axle will be forced into the opposite direction. This is the side for the special torque arm. Rotate the long nut on (clockwise) and tighten it. Now use the same box wrench as a torque arm on this side. The rotating axle (counterclockwise) will always try to tighten the nut. On the other side it will loosen it. Let me know when your ready to upgrade your motor buddy.
 
Back in the saddle again ! Riding again for 2 days and so far so good. I just wanted to touch base and thank dogman, amberwolf and cogman for your helpful insights. I've come to the conclusion that after wiring the motor my installation was unsecure and sorely lacking that resulted in almost sheared wires. A lesson well learned and without being spoon fed. :p
 
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