Just got my trainer two weeks ago. I've done one legged drills outdoors no problems. But I was really having difficulty doing them on the trainer I'd get going smoothly but when I tried to get cadence above 80 I'd develop a clank near the bottom of my pedal stroke. Once I got the clank I couldn't get rid of it: lowering my cadence ior shifting gears higher or lower wouldn't help. Any ideas of what I could be doing wrong or do I just need to keep on riding the trainer?