When putting on my new rack (topeak explorer), the bolt that came with it is too short (longer than the fender one at least). Well actually that's my question, its just long enough to get a couple threads in with the 2 fender eyelets and the rack mount sandwiched in. Shouldn't it be long enough to utilize all threads or at least most for durability reasons? I feel like its going to pull out or snap off come time to load it up with all the gear.. or maybe I'm just doing it wrong