Wahoo Silent Kickr/Kickr Core Faults

[alex_cycles]

I hit it with the blowtorch and two tyre levers. Got it to crack up a couple of mm. (As far as the tyre levers would lever in one go).
Hit it again with the torch, then put two metal plates down to raise the height. A few mm more.

Didn't need the blowtorch again. Just kept raising the height and levering. And now we have this happy sight...

The shaft looks OK. Not even any sign of corrosion. Just a bit of residual locktite or whatever they used. And the washer does seem to be wavy now it's not compressed

So the shaft seems OK. I'll give it a bit of a polish tomorrow. So I'm not feeling quite so shafted now. The new bearings are able to slide on all the way to the end in a nice fit without any discernable slop. (Flywheel had been outside for a while, bearings were indoors.)

 

[alex_cycles]

Thanks for the tips @CXRAndy the blowtorch saved the day with that bearing. I've still got that puller and a bearing splitter on the way though (I love tools so not gonna cry about that.) The splitter will be useful if I ever need to take the pulley off again.

I don't get why they would loctite the bearing on. That seems unnecessary to me.

 

[CXRAndy]

I think it's to stop fretting corrosion on the shaft. Locking the inner race to the shaft. You can get locking loctite easily. Put some spacers under the bearing to get the gap correct before fixing the bearing

The lower bearing sets the pulley/drive belt position in relation to the larger pulley. They need to be online or the edge of the belt will wear prematurely

Use this. https://www.bearingsrus.co.uk/loctite-641-medium-strength-bearing-fit-retainer-10ml/

Bearings are cheap, the shaft not so, would need an engineering firm to fabricate a new one if damaged.

 

[alex_cycles]

Bearings are cheap, the shaft not so, would need an engineering firm to fabricate a new one if damaged.

Yes, that's why it's been a tense few days while I waited to see if the shaft was knackered.

How long does fretting corrosion take to set in? I'm wondering if just applying high temperature grease to the shaft and inspecting in a couple of months might be a better option (for me - to get the job done - think it would be easier to assemble too)? Clearly it's not a permanent "fit and forget" solution though.

 

[CXRAndy]

Yes, that's why it's been a tense few days while I waited to see if the shaft was knackered.

How long does fretting corrosion take to set in? I'm wondering if just applying high temperature grease to the shaft and inspecting in a couple of months might be a better option (for me - to get the job done - think it would be easier to assemble too)? Clearly it's not a permanent "fit and forget" solution though.

Mine destroyed the shaft in little over a month of use

https://www.cyclechat.net/threads/wahoo-silent-kickr-kickr-core-faults.241225/post-5510591

 

[alex_cycles]

Mine destroyed the shaft in little over a month of use

https://www.cyclechat.net/threads/wahoo-silent-kickr-kickr-core-faults.241225/post-5510591

Ouch. Well I want to put it back together and test when the bearings arrive today. So I'll do that with grease and consider it a "practice run" on the re-assembly. Then, if it's behaving well, I'll get some Loctite in and sort that out more permanently in a few days.

My problem is mine wasn't a bargain. I bought it in supposedly "as new" condition and barely used (which is true, you can see it's barely used).
Unfortunately, the legal position there is "Caveat Emptor" so it's either I fix it or see what Wahoo can do for me. But I prefer to try and fix it myself as first option.

The click noise only happens when it's warmed up after about 12-15 minutes.

 

[CXRAndy]

That's fair enough. It will be satisfying to see if your bearings cure the noise. It's a good turbo -apart from

 

[alex_cycles]

All back together and installed ready for a test ride. It went back together without issues.
Woodruff key is a good firm fit so didn't bother thread-locking it since I'll be inspecting soon anyway.
Left the drive side cover off for initial ride so I can hear any noises.
Before mounting on the bike there was a bit of belt-squeal, but once on the bike and spun up a bit that seemed to settle.
Now for a ride.

 

[alex_cycles]

Well there's still a little bit of clatter at times, but it's a very great deal better than it was. I will ride it over the next few days and see how it goes. Cautiously optimistic, but not feeling like I'm "out of the woods" yet.

Also quite conscious of the fact there's still the freehub I could grease, the large drive-wheel pulley bearings I could change and the belt tensioner bearings too. But the fact there's a large improvement seems to me to indicate I was on the right track with the main bearings on the flywheel and small pulley axle.

 

[CXRAndy]

Does your turbo have an Allen bolt in the pulley on the spindle?

If it does, that indicates that it may have been an earlier model. They started replacing the Allen bolt with a wider conventional hex head bolt to increase surface pressure. There was a kit called (K118) or something like that which was new bolt and slightly larger Woodruff key.

Edit- thinking, yours has had loctite applied and that came later, so maybe they went back to Allen head.

I think reducing the belt pressure a little helps with the bearing strain just don't go too slack or it will squeal every time you accelerate

 

[CXRAndy]

A final thought would be to try static balance test. I think you would need to remove the rubber dust covers From the bearings to remove as much drag as possible .

Take belt off, move flywheel to various positions, let go, see if it rotates to a heavy point.

 

[alex_cycles]

Does your turbo have an Allen bolt in the pulley on the spindle?

If it does, that indicates that it may have been an earlier model. They started replacing the Allen bolt with a wider conventional hex head bolt to increase surface pressure. There was a kit called (K118) or something like that which was new bolt and slightly larger Woodruff key.

Edit- thinking, yours has had loctite applied and that came later, so maybe they went back to Allen head.

I think reducing the belt pressure a little helps with the bearing strain just don't go too slack or it will squeal every time you accelerate

It had a wide-headed Allen bolt with an even wider washer. I replaced it with a similar new one, but next time I take it apart I will change it for a hex head, I think. The Woodruff key was a tight interference fit. Had to be quite firm with it.

When I was setting it up today I wanted to back off the belt tension, but as you say it's a bit of a compromise with squealing.

We'll get there. Now I've done it all once, it's not so scary because I know I can do it. But to be honest the Loctite was the cause of both my disassembly problems and I've not used it (yet) on the reassembled Kickr.

I will check the "static balance" of the flywheel next time I have the belt off, which will be within a few days for sure.
My flywheel is date stamped July 2020, and the v5 Kickr was launched in August 2020, so likely one of the earlier v5 models.

 

[alex_cycles]

Swapped the shaft's Allen bolt for a hex head. Needs a flanged one really as the washer under it is deforming into the indentation at the end of the shaft.
But anyway, after that I did an indieVelo iTT for another test. No clattering noise that I could detect. So cautiously optimistic.
Won the race too

View: https://www.youtube.com/live/8NWSsdbgKXU?si=xyFdbMboRj88P68u&t=1021

 

[alex_cycles]

So 4 weeks on and 400 miles of riding/racing and yesterday there was a fairly quiet clattering sound after a 1 hr 20 hard race.
The flywheel was warm. I decided it was due for an inspection. Here's what I found...

That was a brand new bearing four weeks ago.

Looks like the beginnings of fretting corrosion on the shaft too. I've polished that out, put a new bearing in and everything has been very well greased...

The bearing and shaft at the flywheel end are absolutely fine and the bearing is still free sliding on the shaft. Grease still present.

I've ordered some of the Loctite 641 to do the bearing at the pulley end. When that arrives I will get on with that in the hope that it saves the shaft. Also trying to dial in the belt tension so it's as slack as possible without squealing when I sprint.

 

[CXRAndy]

It is so disappointing to see that Alex. I've watched a few of your videos and thought how quiet the turbo sounded.

Here is hoping that the new bearings and loctite see a more permanent fix.