Friday, September 07, 2007

TT Position - Phase II

Aero is important for going faster - that's obvious. But cycling past age 40 would be nice, too, and I'm 39. My new aero position is undoubtedly more aero than my old position, and therefore it's faster; but it puts more strain on my lower back than my old TT position did (and much more than my road position does) because my legs-torso angle is more acute. The last thing in the world I need is a bad back - that'll shut you down fast and for a long time. So I'm going to change again to save my back.

The reason my torso angle is so acute is that I lowered the bars and slid my saddle back at the same time when I developed my new position. I lowered the bars to flatten my back and drop my frontal area - that's standard. But I figured my power output would be higher if I slid my saddle back to something similar to my road position. I think it works - my power seems good. And moving the saddle back gave me an important unexpected benefit: it increased my reach so that my upper arms are at about a 45 degree angle with vertical. That lowers my shoulders and upper body more.

So I need to increase my legs-torso angle without going back to the higher shoulders-torso position. The first obvious thing to try is to slide the saddle back forward - maybe not as far as it used to be, but several inches, at least. That'll raise my shoulders because my upper arm angle will get back close to vertical. To lower my shoulders back down, I guess I'll take spacers out and lower the bars again.

One thing that I have learned in messing with this stuff is how cool Levi and Floyd's positions are on their TT bikes. I mentioned that I changed my upper arm angle away from vertical and lowered my shoulders by stretching out more. They have taken the exact opposite approach and changed their upper arm angles by bringing their bars in closer to the saddle, giving them the 'mantis' look. I'd love to try that, but I'd need a smaller TT bike frame - probably not going to happen. Before I move my position again, I'll photograph it and compare it to my old one so I can see how the angles are changing.