I was supposed to do a 400 last weekend but was completely wiped after 200. Since we were doing our 200 route twice in opposite directions the half way point was a convenient place to drop out. A combination of factors did me in: lack of stops to snack early in ride due to strong tailwind (guys I ride with use powdered nutrition drinks and don't need to stop to fuel), 60 kph cross winds / headwinds for last 100 km, not enough hydration (difficult to reach for bottles in strong wind when riding close, other guys use camelbaks), frequently losing draft and getting hit by wall of wind, probably the biggest was my ever changing fit. I've been moving my saddle and bars around to deal with sore shoulders. Every time I make a significant saddle adjustment it takes up to 2 weeks for my legs to adjust. To finally get my fit perfect I had to move both my saddle and bars up 1/4" last week and I really should have given my legs another week before tackling a long ride.