L01 350W Unicycle 132Wh

[KeithT]

My L01 wheel has suddenly developed a judder at start-up. When I lean firward slightly it begins to judder wildly forwards and backwards with a loud metallic clattering. Lean forward more quickly and it moves as normal. Come to a stop and again there is a clunk.

A couple of weeks earlier I had to remove the wheel to repair a puncture however, I am not aware that I did anything which could have contributed to the problem. 

Is there any other component which might be responsible?

Any ideas appreciated.

[Gimlet]

It sounds to me like you may not have tightened the wheel nuts up enough.

If they've come loose the tapered clamping half washers won't be gripping the axle tightly enough and they'll let the body rock back and forth on the axle flats.

I normally use locktite thread locker on the wheel nuts and tighten them to the correct torque with a torque wrench.

[KeithT]

Thanks, I will check, it sounds a likely culprit although, I don't recall disturbing anything other than the rim bolts whilst accessing the tube.

[Keith]

46 minutes ago, KeithT said:

Thanks, I will check, it sounds a likely culprit although, I don't recall disturbing anything other than the rim bolts whilst accessing the tube.

By "rim bolts" please tell us you don't mean the bolts that go all around the wheel itself? There would be absolutely no reason whatsoever to touch those whilst changing a tire, hence it would not occur to any of us you might have done that.

if you have, indeed, undone all of those then it would explain your problem.  Those bolts hold the motor together, clearance between the stator and magnets is measured in thousands of an inch, loosening those bolts will result in the magnets coming into contact with the stator. Getting the clearance right again isn't going to be trivial, you will need to remove the wheel completely from the EUC, take off both motor covers and use thin card or similar spacers to keep the spacing even whilst bolting up one side tightly. Then remove the spacers and hope the other side will stay centralised when refitted.

[KeithT]

Thankfully, I did not remove any of the rim bolts. I loosened two but realised that I could ease out the tube sufficient to repair the puncture.

I have removed the covers, as much as possible, and found that the axle nuts are loose. Although I have managed to tighten them they are easily loosened by merely twisting the footrest 'bars' anti clockwise. Once I refit the covers is that likely to prevent them loosening? I have loctite but I am loath to remove the axle nuts entirely in case I dilodge some component which is difficult to replace. In any event access is difficult due to the cable which feeds into the hollow axle and prevents opening the case wide.

Do you think I should remove the nuts and loctite them?

Thanks for the earlier advice.

[Gimlet]

I have ground a slot in one side of a socket to make it easier to work on the nut with the wire through it but I can still only turn it a fraction on each twist or the slot will cut the cable.

The monkey wrench is just to hold the frame still but you can put it in a vise or workmate, some people have even made a wooden frame with battens to hold it.

A dog bone wrench also works but you need to dismantle and disconnect the wire to thread it through.

The only things that will come out if you remove the nuts completely and take the pedal frame off of the axle are the tapered half washers and they're fairly easy to put back in place.

[KeithT]

Many thanks .

It looks tricky but I have all of those tools..

One of my concerns is straining the connecting wires between the halves. They greatly restrict access and are difficult to support.

[Gimlet]

On my EYU and IPS wheels there was enough slack on the wires to open the case carefully but on my Got ways and Kingsong I have to disconnect a few.

[Keith]

@KeithT, locktite is fairly thin, if you do not want to take anything further apart, you could put some on the threads then undo the nuts a turn or two so it gets on the nut threads and then do them up again. Obviously, make sure it is the removable (blue usually) locktite not the permanent stuff.

[Gimlet]

4 minutes ago, Keith said:

@KeithT, locktite is fairly thin, if you do not want to take anything further apart, you could put some on the threads then undo the nuts a turn or two so it gets on the nut threads and then do them up again. Obviously, make sure it is the removable (blue usually) locktite not the permanent stuff.

A little white spirit or meths to degrease the threads first might help if you use this method.

[KeithT]

Many thanks .

That appears to have resolved the problem.?

i could not lay my hands on the Loctite, it is blue BTW, but should it happen again at least I know what to do.

Thanks again, your help is much appreciated. ??