Tire Size/ Tube Size Question
At this point I'm sure most of you knowledgeable riders enjoy answering this tire size/tube size question. Some day this will all make sense to me, hopefuly today!!
My bike is a Giant OCR2 road bike, ridden on pavement 99.9% of the time with minimal bumps/ruts in the road or on the paved paths I ride.
Anyways, I encountered a rapidly flattening tube last night. The hole is big enough that I don't want to repair it and besides I have the Philly tri later this month so why not put a new tube in. My question is, my tire is a 700X26C, and the tube that was in there was a 700X28/35. I bought a replacement (Specialized) tube that is 700X20/28 (27 3/4 - 1 1/8) tube. Now I'm pretty sure that the new tube is acceptable as a replacement (although let me know if not), but just wondering why my bike shop would have put the 700x28/35 on when they fixed my last flat? Isnt that size a little big? Is there a reason a tube slightly bigger than the tire would be better.
Also, I'm a big guy (250 pounds). Is there an advantage to using one of these (28/35 vs. 20/28) tires for someone my size? Does one have a higher/lower risk of damage at high air pressures with someone of my size on it?