Originally Posted by
SoSmellyAir
urbanknight just installed his tires. New tires stretch after several cycles of inflation, riding, and losing air. When I first installed my 25 mm GP5K, I freaked out because it measured barely 7/8" wide, but after several rides (roughly 200 total miles over the course of about 3 weeks) it expanded to its nominal width, where it has stayed since. Someone else told me I could have sped up this process by stretching the tire at maximum pressure as it sits in my garage, but it is too much work to inflate before
and after each ride.
As I noted upthread in the first few posts, I first measured the Timekeepers oversized at +26mm before I ever rode them, and they have maybe stretched a couple tenths of a millimeter; I’m not confident enough in the accuracy and repeatability of my tools and technique to even say that much. I’d think 2mm of stretch would be both unlikely and abnormal, but I don’t typically measure my tires, it just sounds like a frightening scenario to have that much stretching going on.