ive searched the entire internet and sheldons site for help. i got a flat on both tires the other week after hitting a rock going like 14 mph. i got home, changed the tubes and went back out. i noticed a few minutes into the ride that it was bumpy, like i was hitting a small ditch every rotation or so. so i checked everything and it looked good. my tires were pretty bad in one spot and i thought it was allowing the tube to hit rim and cause the bump. but my brand new tires are doing the same thing and i still have a horrible bump every time even on a completely flat road. i have tried seating the tube, spraying window cleaner around the edge to seat it better, etc and nothing is helping. is that what is causing my ride to be so bumpy. please help because i have my first triathlon in 3 weeks and i need this fixed asap. i was hoping the new tires would fix it but they didnt. thank you very much!