There has been (alwasy is) lots of discussions about the steep angle v slack for tri. In terms of comfort power, aero etc. but what is your experience with the run as it relates to seat angle. My LBS (a bit retro Italian grouch) view is that you have 26miles to find your legs! But I modified my road bike to a steeper than 75 angle and it appears to make a difference to me. I rode a modified version of the slam last time at IM and the steeper is preferred but this might be because I have put in a fair amount of run training. What are your experiences?
Not convinced that everybody will necessarily be faster on the bike being steep(although many are), but for the run it does seem to make a difference. When I would get off my old road bike it would take a km or two before my legs would start to work during the run.I would agree with your shop that this is probably more important in a sprint than an IM. Dan has done a summary of available studies here. http://www.slowtwitch.com/mainheadings/techctr/seatangle.html
I originally rode a very steep angled bike and ran pretty well off of it. Then I switched to a 75-76 degree angled bike, and ran very much faster. The reason…the shallower bike spreads out the load of the run over the whole of the leg musculature, so that they aren’t fatigues in one group for the run. Think IM Florida, why is everyone’s run about the same as in a hilly IM? Because on a course that flat you are using the same muscle groups and they get more fatigued. The more you can spread the load of the ride out, the less work and one muscle group has to do, the more energy is available for the run.
But that’s just me.
tommy
I don’t have any scientific data, just my experience. Steep geometry seems to work for me when I run immediately after. My road bike is comfy, but not aero becasue I’m more upright. I feel I work my hams too much on the road bike. I feel my hips and quads more on the tri bike. I guess this helps “save” my hams for the run. I tried the slam but this just closed my hips too much making them inneffective, and I it was uncomfortable.
Aloha