Simple to test;
- Place the bike upside-down.
- Spin up the wheel.
- Using a pen or object with a similar blunt point hold it as close as you can to the wheel without it touching.
- Look closely for relative movement at the edge of the Rim.
Anything more than a couple of millimetres change in radius from the axle will have an adverse effect on a Turbo Trainer where the measurement from the Axle to the Roller is always constant.
Sideways movement is more acceptable on a Turbo Trainer as long as the tyre always sits within the Steel Central-portion of the Soft-Gel Roller.