Can a wheel on trainer damage wheel bearings?

I’ve just started using zwift on a wheel on trainer and when I took the bike in for a service I was told the wheel bearings need changing. They were quite right, but is this just a coincidence?

I’ve done about 1500 miles since October so it may just be a bad luck that the bearings have worn down during lockdown.

So can using 5he trainer damage the bearings? Thank you.

Oh, and I was 689th out of 690 on the volcano KOM tonight. Not Last. Felt good to me.

I wouldn’t imagine a wheel on trainer would damage the bearings but I’m sure someone else with more knowledge could comment. I know it can tear up tires due to the heat. Your best bet may be to get a spare wheel to use on the trainer.

As for the KOM, it’s the small victories that you can build on, next time you could be 679th out of 690. Progress is progress. Life isn’t a sprint, it’s a marathon, and some people don’t reach the finish line or even the start line. Keep it up, and Ride On!


I have done over 16,000 miles on my wheel on trainer using the same wheel with no issue with the bearings.


2200 miles on my dedicated indoor training wheel - seems to be no issues as for now. The hub is a lower range $20 Shimano one.

If you’ve over tightened the roller onto the wheel then technically yes you could damage your wheel bearings. More likely the trainer bearings would go first in my experience.

Plenty of Vortex/Bushido users will testify to this.

Maybe you’ve done that and that’s why you are losing valuable watts

The way that most wheel-on trainers attached to the bike, the rear wheel bearings are probably under much less load than when being ridden on real road. In the former case your weight is not on the wheel, its just the roller pressure required to achieve good friction. In the later case, its typically 60% of your body weight and given that the road isn’t smooth, it will be a dynamic load as you hit bumps and ruts. Your rear wheel probably loves the easy life on the trainer (the tyre hates it but the wheel loves it).


As Mark above me says (but worded different) these are the easiest miles those bearings have seen. They have the added benefit of no risk of water ingress or wide temperature variations. Whatever wore them out was happening before you got on the trainer. I could see a situation where damaged bearings continued to cause damage while on the trainer… that’s no fault of the trainer though. Properly adjusted and good condition bearings will probably do 5,000 plus miles on a wheel-on trainer without a second thought given to their care and feeding.

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Thank you all for your really helpful replies. It looks like it is just coincidence.

Since COVID kicked in the bikes been doing at least 100km a week, so I’m learning quite lot about bike wear… I’m on my third chain😀 never thought they needed changing so frequently

If you sweat a bit then this will be dropping straight onto the chain and accelerating the wear.
My turbo chain gets pretty caked up and requires plenty of lube.

Thank you all for your helpful answers. I guess going from 1000miles a year to 5000 was always going to highlight new problems.

Something isn’t right. I’ve done over 8,000 miles on one bike on my (wheel off) trainer and not had to change my chain. It could probably do with a change, but I haven’t checked.

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Chain life has a large number of variables, so you can’t really compare one person’s use with another. Especially if you haven’t checked how much/little it has stretched.

Chain quality, dirt/sweat, how worn the underlying sprockets are, how much you change gear, how much power you put through it, the list goes on.

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In general, indoor riding is pretty easy on the drivetrain, as long as you give it a good overhaul beforehand. There is no dirt/sand indoors, so chain, cog and chainring wear is reduced.



Thanks Sherlock… :wink:

Can you ask Holmes to do a bit more digging for us?

Your wheel bearings will not have been damaged by the trainer if properly lubricated. Not sure how many kilometres you have travelled on those bearings, but they do need to be re-lubricated probably once a year is best. Also, if the cones are not accurately torqued, that too will destroy bearings very quickly. I worked as an aircraft mechanic, so a bearing is basically a bearing regardless of size. I have cleaned hundreds, thousands of bearings, and the ones that get damaged are the ones that do not get lubricated, cleaned properly, incorrect grease, or incorrect torque. Sounds complicated, but really, very simple. If you are willing to tackle the bearings on your own, have a very clean place to start, and clean your wheel, tire so there is no sand or dirt to fall in to small places. Clean every little ball spotlessly clean. Clean the races spotlessly. Do not loose the balls. You will have the same number of balls on each side, so when you get them all out and cleaned, separate into 2 equal piles. small glass bowls are fine, who cares if you eat out of them later, they are clean! grease the races on the hub, place the balls in each race, carefully insert axle with outer cone and thread on opposite cone. Now when I say torqued on cones, this is where experience comes into play. Properly torqued cones will allow the wheel to spin almost endlessly and extremely smoothly when spun by hand. Any roughness, it is either too tight, or too lose. Too tight, wheel slows down quickly, too loose, it feels wobbly and slightly rough. Unless you had the trainer cranked on to max, there is no way bearing will be damaged. Think about all the potholes you have hit! The forces are many times what you will experience with the trainer. Hope this helps.

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I dealt with all those issues with my vintage bikes with cup and cone bearings. With cartridge bearings now more common, you’re more likely to simply replace the cartridge if necessary.

Wow, I knew they were coming! Didn’t know they existed. However, cleanliness is everything as even the smallest piece of dirt will destroy bearings. That I’m sure you are well aware of, but nevertheless, we all need reminding of bearing protocols periodically!

I would sure love to see them!, wonder if I can get mine converted?