back problems

[KnottedYet]

Yeah, you've got the core thing down. If the pain is after 30 miles now and after 45 miles during riding season, then muscle is helping... but now you need someone looking at you. If the pain is only on the bike, they need to look at you on the bike, too.

Have you ever noticed a big leg length difference? (everybody has at least a little difference, it just matters if your body compensates for it or not) Is one pantleg usually shorter than the other, does one leg of your running shorts bunch up into your groin while the other hangs smooth? There are shims and drop pedals to address leg length at the foot, and even subtle things like Brooks or AnAtomica saddles that will give under one side of the pelvis to even out the legs.

Usually there are several things contributing to a problem. If you can eliminate a couple of the more obvious ones, the body juggles the remaining ones without complaint.

It may be that your bike is just too big, but I'm looking at the 30 mile vs. 45 mile onsets and thinking there's got to be a way to eliminate a couple other contributors instead of eliminating the bike itself.