Trainer destroyed rear hub

So I iwas in the middle of a workout and paused to go pee. When I tried to start again it wouldn’t run smooth. I was putting out over 400 power at a cadence of 50 and the target was only in the low 100s. FYI, my FTP is only in the 150s. Paused, unpaused. Even unplugged the my kinetic trainer. I noticed a burning smell and it turns put my trainer was pushing so hard it was melting the tire as I tried to spin. Now my rear hub is completely shot as it started grinding.

Anyone else have this issue before?

Do you use ERG mode? It can take the trainer a few seconds to adjust resistance to a change of input, so when you stopped it upped the resistance to max and then you couldn’t get back on top of it. The fact that you turned it off and on should (probably) rule this out however. Very strange indeed.

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Totally unhelpful reply warning (will not help you to identify the source of failure) but to make you feel a bit better: your LEGS destroyed the rear hub. Hard effort indeed!


i don’t understand the chain of logic from “melted rear tyre” to “destroyed rear hub”

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If you did destroy the hub, how old is it? Ever replaced the bearings?

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If it destroyed the hub then you’ve got it wound on far too tight.

Yeah, dead hub is most likely a result of something other than the trainer. This episode might have brought it to light, but I doubt it is the root cause of the failure.

In 10+ years of hard trainer use and reading on forums, I’ve never heard of an issue like this killing a hub. I suspect something else is at fault here, especially with what seem to be low watt loads in most cases, and 400w+ is hardly bike killing wattage.

I’d look at maintenance history and axle setup and bearing preloading as most likely issues. Maybe trainer roller pressure was excessive, but that would likely be visible from massive tire deformation, so seems unlikely to me.


Only been riding a few years and didn’t know hubs went bad or had to have bearings replaced…My trainer wheel is from my first bike, so I think that solves that issue. Thanks for the insight.

The melting part I mention is from all the rubber build up on the trainer in the photo. That is JUST from yesterday. I always keep the contact point/roller super clean. I could smell it burning while trying to pedal. I actually thought it was the trainer starting to smoke. That is how hard the trainer was pushing against the tire.

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I expect a bearing failed as I’ve never known a hub to fail from trainer use.

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You’re saying the trainer roller is destroyed, not your bike wheel’s hub.


  1. Your wheel-on trainer puts a lot of strain on the tire because it is a small bit of material. If your tire is slipping, it will make more heat.
  2. Not putting enough load on your tire with the adjustment knob will cause your tire to slip a lot.
  3. Your standard bike tire’s rubber doesn’t have the heat range to deal with the strain of a poorly adjusted trainer; and barely works for a well adjusted one… hence the existence of a “trainer tire”
  4. your roller isn’t ruined, just scrap off the rubber deposit.
  • He is actually talking about the wheel hub and related bearings, as he further clarifies in a reply to my comment above.

  • He clearly is using the green Kinetic trainer tire as seen in the picture above, not a regular black road tire. So this is not an issue like you describe.

  • image

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I don’t know if he’s using the word “hub” the same way you think he’s using it - as it is commonly used.

The death of the hub would not be intertwined with the death of the tire. The hub likely wouldn’t fail that suddenly.

That tire could be any green bike tire - eg

Per his OP:

And the following info I already quoted, seems like bike wheel hub and bearing concern (grinding) to me.

Yes, it is a bit confusing because there are multiple concerns mentioned, but I think he is talking about the bike wheel for that part of it.

Sure, it’s possible to be a different tire, but considering the Kinetic trainer and Kinetic happens to offer a green trainer tire, I think it’s a reasonable assumption that he has a trainer tire. Good idea to confirm though, with respect to the rubber issue. But my money is firmly on it being the Kinetic tire.

It is the kinetic trainer tire.

As far as me calling it the rear hub. I can completely pull the axel out and some metal fell out with it. Doesnt sound like hub was the right word.

I think now I just need to find out why TR wouldn’t smooth out. It sometimes makes me put out high power the first couple seconds of a work out and then I am good to go. In this case they were 20 seconds or more without smoothing out.

Gothcha… that’s strange they happened at the same time then. Were you using the bike’s QR skewer or the ugly one that came with the trainer?

Last question first. This is tr acts on startup. If you have a smart trainer it’s known to jack up the resistance if you take a pause - or there is a drop out of sorts.

Metal shouldn’t fall out of anything. So in a redneck voice “ders yer problem right der”.

Take the bike off the trainer. Can you spin the roller without noise? If yes. Trainer is fine. Move along.

Take the wheel off the bike. Remove the skewer. Can you spin the cassette with your hand? Does it only move one way and click? If this isn’t moving then the rear hub and pawls need help.

If that all works. Hold the wheel by the ‘axle’ if you will. Where the qr would go in.

Give the wheel a spin (you might need a friend) in both directions.

Edit: add. If all this works out the wheel on and try to turn the pedals. Do they move freely? Does the rear mech move and the chain cleanly move through?

The trainer should move freely. The cassette spins one way (like when you backpedal) and not the other way. The wheel should spin freely on its bearings.

Update. Took the rear wheel in to the bike shop. Hub rebuild. Bearings where basically falling out. Wish I could upload the video I took.

I have a rear wheel for inside and a rear wheel for outside so I dont have to change tires. I hate it and suck at it.

Took my outdoor wheel and put it on the trainer. Calibrated it all and did a TR workout with no issues. My watch was reading about 20w less then the trainer, but other then that all good.


Glad you got it all sorted and running again. :slight_smile:

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