I've been running 25mm pro races on my training bike and the LBS only carries 18-23mm tubes. Lately I've been having a buttload of flats but can't see or feel anything that would have caused it. The question is, is the mismatch causing this, I don't know, is the tube expanding too much or something? Of course the people at the LBS say the tube will work fine but wouldn't the tube company say so on the box? Why would they limit their market? Would it be better to use the next size up, 28-35mms? Thanks