Suspicious motor noise turns out to be "something about the back wheel

[sdcoffeeroaster]

I was pretty sure the noise (random rattling, clicking metallic noise when pedaling) I was hearing under light or no load was coming from the motor. No sound under medium to heavy loads. I had taken the Exile+ freewheel apart and inspected the spring and 4 pawls as well as the 4 cartridge bearings. All looked good. I cleaned the pawls up and used some very light freewheel grease on them but the noise persisted. I did not have a new stock Shimano chain to try and my chain was showing some signs of wear on some links so I installed a bulk 701 chain I bought from AliExpress a while back. I went for a ride and that chain broke right in the middle on a slight hill about 5 miles out. Anything from Aliexpress can be suspect I've learned but was it the chain or the worn cassette that did it? I think the motor noise was gone on that short ride but I don't remember. I do carry quicklinks with me so I managed to get back home.

Yesterday, in desperation, I dug out and installed my original Raceface rear wheel and cassette along with the chain used on that combo. The noise is gone now and so it wasn't the motor after all yahhhhh!!!! The suspect wheel (Speedtuned Exile+ CF) looks good as far as the freewheel goes, no wear on the 4 pawls but lots of wear on the aluminum cassette driver of course since it has at least 2000 miles on it. The cassette fits pretty loose on the driver until it's tightened (lots of radial and circumferential play) and I will do some comparing today to how much of that is normal. I would like to use the Exile+ CF wheel since it's 300 g lighter but since I'm using the 5 cartridge bearings and 5 pawls Novatec 462 (not the stock 162) with the steel cassette driver that NEVER shows any sign of wear, it is much better suited for ebikes I think. I have a new SLX cassette (been using XT) that I have as a backup and new 701 chains coming today. I'm debating if I should try them on the Exile wheel or maybe even buy a new cassette driver for the Exile (the cartridge bearings are all good). I'm not sure what could be generating this sound in the Exile at this point and 300g is not that big of price to pay for a really strong rear wheel.

 

[RickBullotta]

Check your hub axle (not the through axle). I've cracked two of them. I'm guessing most weren't designed for the loads of an eMTB.

 

[sdcoffeeroaster]

Check your hub axle (not the through axle). I've cracked two of them. I'm guessing most weren't designed for the loads of an eMTB.

Oh now I realize the axle you mean. It's the one left over in the hub once you remove the freewheel assy. I've never had that one out and will check it today. Thanks

 

[deksawyer]

I had what can be described as similar noises to yours, which I thought was my motor - turned out to be a rear wheel bearing. ?

 

[sdcoffeeroaster]

I had what can be described as similar noises to yours, which I thought was my motor - turned out to be a rear wheel bearing. ?

The bearings feel OK. But it does seem a bit sensitive to the last tightening sequence. It doesn't feel gritty or anything but it doesn't move as smoothly without some drag as it is tightened. Maybe some roughness in one of the bearings is causing this. It is not terrible and moving the individual bearings doesn't reveal any issues. There are 4 sealed cartridge bearings in this wheel. If I replace the freewheel assy I'll do the two hub bearings at the same time to be sure but I'll probably use the Raceface wheel for now and see how the Novatec 462 works out long term.

 

[downhilllister]

The bearings feel OK. But it does seem a bit sensitive to the last tightening sequence. It doesn't feel gritty or anything but it doesn't move as smoothly without some drag as it is tightened. Maybe some roughness in one of the bearings is causing this. It is not terrible and moving the individual bearings doesn't reveal any issues. There are 4 sealed cartridge bearings in this wheel. If I replace the freewheel assy I'll do the two hub bearings at the same time to be sure but I'll probably use the Raceface wheel for now and see how the Novatec 462 works out long term.

Let me know how the the 462 works out, Just waiting on mine. With Covid it may be a while.

 

[sdcoffeeroaster]

Let me know how the the 462 works out, Just waiting on mine. With Covid it may be a while.

So far so good. I think something other than aluminum is better for the cassette driver. Steel just doesn't wear and having 2 outboard cartridge bearing is great. If anything I've heard the 5 pawls can be the weak link on the Novatec hubs but never had any issue with them before. I plan to rebuild the older hub even though it is an aluminum freewheel assy. Hadley makes a titanium freewheel assy I'm told. It's a small US company that doesn't advertise much and the prices are very reasonable at about $750. for a set of wheels using Stans MK3 rims. That is another good ebike option I think.