Ammonia smell??

[jobob]

I used to experience it a lot when I first started biking, and it seems to be pretty common (here's a link to a really old post of mine about that). Almost never nowadays, since I eat better beforehand and while I'm riding, plus I'm in much better shape.

Edited to add: Not to imply that you're not in good shape ! I think in your case it's because you're not eating enough carbs. Altho I've also read that eating some protein on longer bike rides is good too, it keeps you from metabolizing your own muscle protein which is probably what causes the ammonia smell.