Axle partially spun in the dropout, could it cause this issu

Quick rundown of the issue. Bike was operating just fine then I stopped for a second to check something on my APM, went to take off and the bike barely moves. Checked a couple things and then the bike wouldn't power up at all. All the readings were great but the wheel wouldn't move when giving it throttle. John in CR was kind enough to give me some pointers (Thanks John!) and this is the rest of the story.

Here's a video I took of the wheel being spun by hand.

http://youtu.be/go0rhSdIMnQ

https://www.youtube.com/watch?v=go0rhSdIMnQ&feature=youtu.be

I tried this with the motor wires connected and disconnected same effect. When I removed the disk side nut I noticed this, the pic shows a little gap between axle and frame but it was wedged in there very tight. Looks like the axle tried to rotate in the rear dropout just on that side, yes there was a torque arm and no I don't believe it was effective, I didn't even recognize what kind of torque arm it is. I tried binding a couple nuts on the axle and wiggling it free, no luck until I used a rubber mallet while wiggling the axle back and forth with a wrench.



Once I removed the wheel I used that same wrench to manually turn the axle and while there is resistance the resistance is even while you spin it. Im considering the idea that the axle may have been bound up and couldn't rotate properly. How should this rear wheel feel when spun by hand? Id say there is at least 3lbs of resistance.

Any Help would be awesome!
Dan L.

Almost forgot, does this look as it should? To my novice eyes it looks like there was a secondary hole drilled into the axle for no reason.

What is that gunk in the axle cutout? Looks like solder or something. I hope it's hot glue and not something conductive.

cal3thousand said:

What is that gunk in the axle cutout? Looks like solder or something. I hope it's hot glue and not something conductive.

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It appears to be sealant, not sure if it's conductive.

I would like to point out this bike was built for a customer at an electric bike shop in Fort Collins Co I believe. I'm the new second owner.

Can you show a couple different angles of the axle sitting in the dropouts?

Your spinning resistance is due to shorted phase wires IMO. Possibly the phase windings but more likely the good old Crystalyte axle wire in/out thing.

Ykick said:

Can you show a couple different angles of the axle sitting in the dropouts?

Your spinning resistance is due to shorted phase wires IMO. Possibly the phase windings but more likely the good old Crystalyte axle wire in/out thing.

Click to expand...

Phase wires seems to be the consensus but because it doesn't cog the whole way some think bearings or rust. Just don't want to have to separate the motor unless I have to!
I'll try and put the wheel back on right now.
Thank you for your reply.

Dan L.

That is true about the partial resistance in relation to rotation. Have you tried shorting phase wires together (disconnected from controller of course) to compare what shorted wires would feel like?

May very well be something gone physically wrong inside which would need to be opened-up one way or the other anyway.

It would be helpful to see how the axle fits in the dropouts?

Snapped some pics but then I had to walk the dog and grab dinner! Soon as I'm done with that I'll post them.

Here we go!







It looks like there is plenty of room and I suppose that's the case but its pretty tough to get the axle in there but once its in theres all that extra space that the axle gets twisted in.

I will do my best to short the phase wires tomorrow and report back.

Dan L.

If a motor is very hot, and you stop, it causes a heat spike. That can fry all your halls.

If you don't have shorted phase wires, check the halls next. If your phase wires are shorted inside the motor, the resistance will be the same when you have the big wires touching at the plug, or not.

Did this bike have a torque arm (TA)? The fit of the axle in those dropouts would not be acceptable to me. Too loose and shallow worries me that the axle could "walk out" of the dropout under load. I'm surprised there's not much in the way of marks left by the washer & axle nut?

But anyway, if the axle actually spun maybe the wires are physically bunched-up inside causing the varying friction when rotating? Shorting the phase wires will help better your understanding but sadly I feel that's gonna be a tear-down one way or the other.

And once repaired, I'd focus on re-shaping and reinforcing those dropouts to better fit the axle. And definitely need good TA's.

There is too much going on to say with any certainty where the fault lies, it sounds like it could even be the tyre on the mudguard or the brake disc, or freewheel. The wheel needs to removed from the bike and held in a vice by the axle flats to eliminate any possible rubbing of external parts. The wiring even if rubbing in the spacers/axle would not cause that degree of noise or feel, it is simply too close to the centre of rotation to apply that sort of drag. It doesn't look like a shorted phase either, it certainly seems to be a mechanical rub, eliminate all the exterior possibilities then if its still there you have to open it up.

And I have to agree with the others here, that dropout is grossly inadequate!! but there is enough room to create a decent location for the axle so the wheel could be made to be fit and forget, at the moment it is severly fit, worry, keep your eyes and ears on it wear a good crash helmet and don't go too fast! And that doesn't include the $$ cost of electrical carnage a spun axle can cause!

Ykick said:

Did this bike have a torque arm (TA)? The fit of the axle in those dropouts would not be acceptable to me. Too loose and shallow worries me that the axle could "walk out" of the dropout under load. I'm surprised there's not much in the way of marks left by the washer & axle nut?

But anyway, if the axle actually spun maybe the wires are physically bunched-up inside causing the varying friction when rotating? Shorting the phase wires will help better your understanding but sadly I feel that's gonna be a tear-down one way or the other.

And once repaired, I'd focus on re-shaping and reinforcing those dropouts to better fit the axle. And definitely need good TA's.

Click to expand...

The bike did have a sort of TA but it looks odd and ineffective.

Good Lord it is very shallow, was really glad that an issue popped up and I had a chance to see that before things really went south!

Tear down is in order if not for the sole reason to see what shape the motor is in.

I never intended to use the Ute as an electric anyways I bought the bike strictly for the motor and wiring etc, the Lifepo4 battery and bicycle were just bonuses to me. Im looking to either get a FS mountain bike or use my old Rockhopper. I did however want to ride this frame till the end of the season here but Id be better off swapping things now I think.

dogman said:

If a motor is very hot, and you stop, it causes a heat spike. That can fry all your halls.

If you don't have shorted phase wires, check the halls next. If your phase wires are shorted inside the motor, the resistance will be the same when you have the big wires touching at the plug, or not.

Click to expand...

Hey Dogman, I only rode it about 3 blocks when I pulled over and probably averaged 20mph in that time. The controller is sensorless, does that bypass the halls?

As always...............Thanks Dogman.

Dan L.

Tench said:

There is too much going on to say with any certainty where the fault lies, it sounds like it could even be the tyre on the mudguard or the brake disc, or freewheel. The wheel needs to removed from the bike and held in a vice by the axle flats to eliminate any possible rubbing of external parts. The wiring even if rubbing in the spacers/axle would not cause that degree of noise or feel, it is simply too close to the centre of rotation to apply that sort of drag. It doesn't look like a shorted phase either, it certainly seems to be a mechanical rub, eliminate all the exterior possibilities then if its still there you have to open it up.

And I have to agree with the others here, that dropout is grossly inadequate!! but there is enough room to create a decent location for the axle so the wheel could be made to be fit and forget, at the moment it is severly fit, worry, keep your eyes and ears on it wear a good crash helmet and don't go too fast! And that doesn't include the $$ cost of electrical carnage a spun axle can cause!

Click to expand...

Thanks Tench,
The video sorta kinda shows the rear caliper off the bike and it wasn't rubbing on the fender HOWEVER I did notice that at some point it did rub against the motor case right on the side of the motor. The mark is only a few inches long not completely circular.

So just put one axle end into the vise using the flats sides and spin? Either way I guess Im doing a teardown with every fix Im gaining more confidence on these bikes and from what I understand if you own one you should know how to do this!

Yeah quite frankly I was astonished/freaked out when I saw the lower part of the axle never even made it into the dropout, then I saw the gap, pretty horrifying! Goes to show even if you have a shop do the work like the gal I bought the bike from doesn't mean its right. Like the old saying goes, if you want something done right, do it yourself!

Dan L.

That dropout looks ideal for attaching a steel home made torque plate. If it were steel it could be the same (additional) width as the bike and have a lot of area to use nuts and bolts as fasteners. It looks about 4 mm thick.
otherDoc

UPDATE!

Took this to a buddies house he is an ex bike mechanic, ex motorcycle mechanic and currently a Master electritian. The first thing he noticed that I missed was the covers have been off previously (hmm) while inspecting the wheel I noticed that it is not a 3540 but a 5305 72v model. Currently Im using a 4825 controller, is this an issue? I will be ordering a 72v controller in the next couple days depending if we get this thing working properly.

When we put it in the vice and spun it, it acted differently than when it was on the bike making me think the axle was torqued into the dropout funny and perhaps was making it difficult to rotate more freely. It still wont go 3 rotations when spun but maybe a rotation and a third.

He did a quick check on the wiring and came up with (in his words) the winding .02 and the ground infinite. He said the halls were coming up with some odd numbers and wanted me to ask about the pinouts and what numbers should be coming up on the reader.

After separating the covers we noticed what looked like a gap that should have a keyway, does this hub need a keyway? In the pics below youll notice some debris around the magnets and that little gap on the axle.

Heres some pics!

The model number


The halls wiring looks a little crimped.


Some debris


The keyway gap???


Last shot


Tonight we are going to hook up the wheel again while its attached to the vice and see if we can get it to spin correctly.

Any tips or insights are GREATLY appreciated!!!

Dan L.

That axle should have a key in the keyway.

I don't see how it would prevent rotation without it (it's just a interference press fit)

cal3thousand said:

That axle should have a key in the keyway.

I don't see how it would prevent rotation without it (it's just a interference press fit)

Click to expand...

Thanks Cal! So one keyway on both sides? Would you know of a source for these? I was thinking perhaps electric rider.

So without the keyway I should still be able to test run the wheel on the vice?

Thanks!

Dan L.

Danschutz said:

cal3thousand said:

That axle should have a key in the keyway.

I don't see how it would prevent rotation without it (it's just a interference press fit)

Click to expand...

Thanks Cal! So one keyway on both sides? Would you know of a source for these? I was thinking perhaps electric rider.

So without the keyway I should still be able to test run the wheel on the vice?

Thanks!

Dan L.

Click to expand...

I would think on a vice, you won't have enough resistance to overcome the pressfit, so yes. But with an actual load, it is too much.

Only one side of the axle should have a key. Not sure where you could get one, but you could easily make a suitable one. Or go to a shop. It's a tiny piece of metal

From what I see, your axle is already out of angular alignment about 180 degrees

cal3thousand said:

Danschutz said:

cal3thousand said:

That axle should have a key in the keyway.

I don't see how it would prevent rotation without it (it's just a interference press fit)

Click to expand...

Thanks Cal! So one keyway on both sides? Would you know of a source for these? I was thinking perhaps electric rider.

So without the keyway I should still be able to test run the wheel on the vice?

Thanks!

Dan L.

Click to expand...

I would think on a vice, you won't have enough resistance to overcome the pressfit, so yes. But with an actual load, it is too much.

Only one side of the axle should have a key. Not sure where you could get one, but you could easily make a suitable one. Or go to a shop. It's a tiny piece of metal

From what I see, your axle is already out of angular alignment about 180 degrees

Click to expand...

I'll see if I have some suitable material to make that key tonight.

So that would obviously be an issue with the wheel trying to move under power?

I hope you know how much I appreciate your input. Im just a noob with working on bikes much less working with an electric bike.

Dan L.

Danschutz said:

I'll see if I have some suitable material to make that key tonight.

So that would obviously be an issue with the wheel trying to move under power?

I hope you know how much I appreciate your input. Im just a noob with working on bikes much less working with an electric bike.

Dan L.

Click to expand...

Yeah, I believe so. That's why it's not lined up right now in the pics. If you were to reassemble the motor and run it under a load and disassemble again, you'd probably see that it has changed angles.

No worries on the help. I'm glad to help someone that has taken the initiative to do some of the work on their own.

BTW, how did you come about owning this motor with such questionable assembly?

I spied an ad in the Colorado Craigslist, I live in Wyoming. Anyways I figured road trip! Me and the wife drove 4.5 hours to buy this bike. I had talked with the owner and the gal took all the pics I wanted and answered all my questions. She said the bike had a little over 30 miles on it and it was simply way to big and heavy for her. She had picked out all the parts and had a bicycle company in Fort Collins I believe order and install all the parts on a year old Kona min-ute.

Once I arrived I took it for a 10 minute spin and although the tires needed some air the bike road amazingly well. It also came with a Electric rider Lifepo4 48v 15ah battery. The gal stated that her cancer was back and she didn't have enough energy for such a large bike. Well gosh Im familiar with cancer patients and couldn't get myself to negotiate with her on price lol, in hindsight I should have. I still think I got a good deal, she even had the original rear wheel for the Kona so I swapped it back over to a peddle bike and plan on selling it. I paid her 750 bucks for the whole thing. Still think its a decent deal if I get this wheel to work.

The wheel install is pretty horrible and I think someone got taken advantage of and that was either her or me lol. The inside of that hub looks imo really clean minus the debris which is probably from the old keyway. I am optimistic that everything will turn out well.

Dan L.

Dan,

I'd say no, don't try to power the motor until you get the stator secured to the axle with a "key". Be sure whoever is doing that rotates it the correct direction to relieve stress on the wires from the partial spin. Since that's an obvious problem inside the motor, and it was working fine before, then it's most likely the cause of a short. That short could have blown your controller too.

Get the stator rotated back and key in, before doing anything more. That should give a bit of slack in the wires to inspect them. Press the stator out of the magnet ring (not by pressing on the axle), and then you can use a magnet and a 5v source to check the halls. They sense a change in magnet polarity, and when supplied 5V and a ground on the 2 supply wires of the 5 hall wires (typically obvious which are which), then the hall will pulse a 4-5V on it's signal line. You should test that while you have the motor open, for the likely event you run a sensored controller in the future.

You also want to check the phase wires for shorts to the stator, and each other. The last part is more difficult because the other ends of the 3 are tied together. You'll want to look for cuts in the phase wires that could have occurred from the stator spin on the axle.

Another reason you need to press the magnet ring off of the stator is to find and remove all those metal bits, which are likely parts of the axle key. The air gap between the stator steel and magnet ring is quite small, so bits of metal left behind will cause noise and problems. The magnets are very strong, and manual pressing off will probably be needed, so be careful not to catch your fingers in there. It's a job easier for the large guys, because we can use mass for a clean smooth push.

The Crystalyte axles have had the key way machined on the wrong side for quite some time now, if they had used a key when they installed the axle the wire channel would not align with the point the phases and halls exit the stator. All the crystalyte motors have not had a key fitted for the last couple of years, yours has not slipped! Your key has not disintegrated, it never had one!

On the plus side I have never seen an axle spin in the stator, personally I don't think it is an issue, just leave it as it is, the chances of getting the axle out and back in again with out damaging it are VERY SLIM!! The press fit is so tight they often bend during removal.

A lot of people have offered advice on this axle issue, I know Cal has had experience of removing and changing axles, I have done many, and the missing key is NOT an issue, the axle will not rotate!

A replacement axle I have made to replace broken axles in Crystalyte motors, (mine do use a full length key) you will also notice the key way on mine is the opposite side to the wire channel so it can be used with correct wire channel orientation.

Don't stress too much, the axle hasn't spun in the stator. (Dammit Tench just beat me to it! ) If it had, the phase and hall wires would be broken and twisted around. The wiring on the halls looks completely normal by the way.

The slot you can see on the axle looks like the wire slot- if you have a look down the keyway slot on the stator/rotor or whatever you call it, you might see the key in there.

If in doubt, clamp the axle in a vice and try to twist the windings/stator on the axle. I bet it won't budge.

The hub motor shouldn't free spin much at all- it'll "cog" as the magnets run past the windings.

The best way to test is with an ebike tester- easy to buy from ebay, cellman or lyen. Best $25 ever.

A simple test for your phase windings is to spin the wheel by hand.. Now join any two phase wires together and it'll be very hard to turn. Now join all three and try it again- it should feel slightly different (sometimes a little bit easier to turn than just two phases joined). If there is no difference between phases joined and unjoined then a phase has shorted to the stator or another phase.

It's already been covered but there are so many variables with a problem like this so you need to be methodical.

Test halls.
Test phases relative to each other and ground. Make sure the wires are all good (no melting, splitting etc).
Test wheel bearings
Test all wires to the controller- I had a broken hall wire just where it bends out the axle and it was an intermittent fault- very annoying.
Test connectors to the controller- especially halls plug.
Test battery connection to the controller.
Check BMS if fitted- is it cutting voltage?
Check throttle and connector
Test controller- you really need an ebike tester for this- or of course just hook it up to the wheel and try again. Wiggle the connectors/wires as you try...
Make sure there is no mechanical rubbing like the caliper on the motor.

Good luck!