Hi Dan,
I know that you have done more than your fair share fo observations and testing of different cycling set ups. So I'm hoping that you might have some insight to a problem that I'm having during Ironman racing.
During every Ironman race that I've done (eight, two in kona) near mile 70 on the bike my hamstrings start to tighten and stay that way until I finish the bike. Once on the run the tightness eases somewhat until about mile 12 and by mile 15 my hamstrings begin to cramp or even seize up. By stopping, walking and streching at every mile from that point on I'm able to get through the rest of the run but I'm always just on the edge of cramping during that time.
I can't duplicate this during training or at any other races shorter than Ironman. I feel that my fluid and electrolyte intake is sufficent. I'm riding on an Aegis Trident with the saddle set in the neutral position and feel very comfortable in the aero position.
If you can offer any thoughts or comments it would be much appreciated.