I've had a 1up for a few years. They're well built but the resistance on mine has been flakey. I've read of others who have had the same problem. After about a year I had to replace the friction unit. The manufacturer was great about sending me the part -- no shipping charges and no need to return the old unit. But it only partly fixed the problem.

What will happen is this: you start an interval. About 45 seconds into your interval the resistance unit will suddenly bog down. You downshift. You downshift again, trying to maintain a cadence. Then a few minutes later the resistance will gradually ease and you can upshift again.

It's not a horrible problem, but for an expensive unit, you'd expect more consistent resistance.

I've heard really good things about the Kurt Kinetic trainers, which are sold on the 1up website. If it's not too late, I suggest you try one of those instead.

Best of luck!