It's a pretty good trainer for mountainbikes, because you don't have to put a slick on the back. I ride one, but there is an issue with wheel slippage (the contact-wheels on the trainer don't pinch the rim hard enough) when you crank up the resistance (which isn't much). If you ride it with a road bike, the rims are narrower and you really notice the wheel slippage on the power-portion of your pedal stroke (probably why a previous poster said it might help you with your pedal technique). It gets the job done cheap, but I love my rollers.