Rumbling noise on new trainer, particularly in the harder gears. Indexed to the best of my ability, cassette brand new, chain with a moderate amount of wear, but otherwise clean.
New trainer set up incorrectly or drivetrain issue?
byu/pghrare inbikewrench
by pghrare
2 Comments
This happens in any low gear, even on the bike itself, there’s just no wind noise to mask it or rubber tires to help absorb the vibration (and on the bike, it only happens when you’re doing 30+ mph, dependent on gearing)
It’s called chordal action, there’s nothing you can do about it. Some of the buzzier noise can be the chain and keeping it lubed properly is important but that low frequency hum/rumble/buzz is not going to go away.
It’ll also sound different at the same rpm at different resistance levels because part of it is the chain under tension between the crank and the trainer is going to have different harmonics if you’re pushing harder vs lighter, but the low level rumble will still be there
Edit: this is also one of the reasons trainers tell you to use the small ring instead of the big ring, lower chain speed reduces the severity
Most times when you pull the rear wheel off things aren’t aligned as they are on the trainer. You may need some small adjustments to quiet it down.