Train your weakness, race your strength....
Train your weakness:
The weakness for you is position and flexibility. So, yes, adjusting the bike fit will help you generate more power, but will not improve the weakness. Talk with Chris about which muscles in particular need some focused stretching to allow you to generate power in a good aero position. This will be more beneficial in the long term, then simply adjusting the bike to fit your overcome your current weakness. The second weakness would be generating coordinated efforts in the different position when compared to MTB. In the forward flexion position, compared to the relatively upright riding on the MTB, you will be forced to use much more hamstring, and will not be able to make use of hip flexors, until you develop better strength in the shortened position. And this means more time in aero. As we have seen with Stephen and Jen who are both extremely strong on the road and MTB, they have not been able to transfer that power into an aero position. My suggestion for now, is not working HARDER, but working longer in aero...the best advice this month for those wanting to improve TT times...tape the Tour, and enjoy some long easy spins in aero watching the footage in the evenings. It does not need to be hard efforts, just easy spinning, allowing the neuromuscular patterns to develop, and the range of motion to be improved. These sessions do NOT need to take away form your enjoyment of outdoor training, and can simply be done as recovery or "down-time" exercises as if you were doing a long stretching session.
Race your strength:
For the time being you are stronger sitting up and standing, so use these skills in your TT until you have developed more flexibility and power in aero. So, stand on the hills, push hard, and go back into aero once you have got your speed up at the crest. Have a look at the following video to see that power CAN be created in aero position:
http://vimeo.com/12297942It will take some time to develop these skills, so again, think long-term. Specific flexibility work in training, and neuro conditioning to allow you to remain aero and generate power in teh future.