I'll get my DH to take a look at the bike fit some more to see if there are some additional tweaks. I think it's just primarily a stamina issue, but I sure wish I had more warning rather than just a flip of the switch! ("Hello? This is your 5-minute warning speaking.") But we've logged over 650 miles over the last 3 months, so if I can get stronger by letting it sneak up on me, all the better. Some days are good and some days less good, I never know which I'm going to get Our commute is a pretty short one - we generally do about 12 miles total for the day, with an extra loop thrown in on the ride home. Longer rides are for the weekends.