My trainer tire has cracks running along the length of the tire. They cracks seem to go in pretty deep, but don't go all the way around the tire. However it still has quite a bit of rubber on it and doesn't seem to be worn too much. I also don't think I have put that much mileage on it, but it is probably 5 years old, but only used for maybe 20-25 sessions.

I'm using a fluid trainer so I'm not really worried about being hurt, but I'm wondering if I should worry about it breaking and coming off the rim and causing some kind of damage if it gets caught in something.

Picture of tire

  • 2
    First you should check the tire pressure. The cracks suggest the pressure is too low. As to tire failure, it's unlikely that failure would result in injury or significant damage, but you probably should plan on replacing the tire some time in the next year or so. Feb 22, 2021 at 20:46
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    I don't have or use a trainer, but I'd be happy to wear it through to the canvas/threads before replacing. Its not like a flat will result in a long walk home.
    – Criggie
    Feb 22, 2021 at 20:49
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    @Criggie Yeah, it's nice to not have to be worried about the walk home, but I'm a little worried about the tire completely falling apart and mangling the wheel. The wheel/flywheel has quite a bit of momentum. However I guess if the tire were to have an issue, the fly wheel wouldn't be in contact with the tire.
    – Kibbee
    Feb 22, 2021 at 20:56
  • @DanielRHicks I have pressure at around 90 PSI as measured by my pump. The max tire pressure as labelled on the tire is 120 PSI, so I figure 90 PSI should be sufficient. I try not to put the roller too tight against the tire as to cause a lot of deformation.
    – Kibbee
    Feb 22, 2021 at 21:01
  • 1
    I'd be tempted to go with the max 120psi as harshness isn't an issue on a trainer, and the higher pressure will result in less tread flex and thus wear.
    – MaplePanda
    Feb 23, 2021 at 5:10

1 Answer 1


I wouldn't hesitate using a tyre in that condition on the trainer, in fact that's exactly the sort of condition i might expect to start using a tyre on the trainer.

The small cracks likely mean the rubber is deteriorating and may be less grippy, but that's of little worry. It's very unlikely there is substantial damage to the actual carcass of the tyre.

Finally, the absolute worst case scenario is a small split begins, the tube pokes through and bursts - however positioned where they are there is very little chance of the beads becoming unseated. So maximum damage is the embarrassment of explaining to people you got a flat on the indoor trainer.

  • 3
    It may also shed rubber nodules (or "marbles" in the car racing world) so don't run it on your best white axminster carpet !
    – Criggie
    Feb 23, 2021 at 9:43

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