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Are steeper geometry tt bikes faster - ???(7 posts)

Are steeper geometry tt bikes faster - ???surf
Jan 3, 2002 8:03 AM
My question is triathlon related. I always read about tri bikes and the steeper time trial bikes being faster for short distances. I would think that the bikes with slacked geometry allow for more muscle usage and would be faster. I have ridden my bike both ways just by sliding the saddle and flipping the seat post (not sure exactly how much difference that makes but I can really feel it). What would you do for triathlons (sprint and Olympic) I understand about saving the legs and that the forward geometry utilizes more of the quads but in the sprint distances I just want to move as fast as possible.

I have aero bars on and can reach them fine without the forward geometry. I heard that aero bars forced some riders to move forward to reach them.

Also, I heard that when you are more forward you can spin faster but moving the seat back does not seem to slow down the spin.

Also, is this forward position harder on the knees? I know with the modifications that I do to my road bike it still wont even come close to moving as far forward as a tri bike but I can still really feel different muscles working.

As for trying both and seeing what's good for me. I have done that but since I'm new to the road I'm slowly getting faster so it's hard to tell.

If it makes a difference im about 6-2 185

Any with experience here?
thanks!!!
if...Dog
Jan 3, 2002 9:07 AM
I think those bikes are considered faster IF you are in a low aerobar position. It allows easier breathing, as it widens the angle between your chest and thighs.

Dog
ExactlyKerry Irons
Jan 3, 2002 6:06 PM
For many road riders, they are already in a low position on the drops. Going to aero bars can restrict breathing - it's easier to pedal due to lower wind drag but you aren't any faster because you can't breath as well. Going to a steep seat angle opens up your chest and allows you to get a flat back without breathing restrictions. It's not about gears or cadence.
re: Just Shy of Clydesjrm
Jan 3, 2002 9:39 AM
Steeper geometry and a forward rider bias allows you to stay on top of a taller gear. Good luck
Tri geometry tt bikesTig
Jan 3, 2002 9:48 AM
I've always heard that tri bike forward seating is for an easier transition from riding to running. Many modern aerobars allow you to position your arms further back since the arm pads can be located behind the handlebars. Go with what is most comfortable and efficient for YOU. I've kept the saddle at its aft position when using aerobars to keep my knee-to-pedal-axis relationship the same. I like to rotate my hips forward, flattening my back more and stretching out on the bars for comfort and to open up the chest cavity and abdomen for breathing.
re: Are steeper geometry tt bikes faster - ???brider
Jan 3, 2002 11:07 AM
Both work for either, it's really a matter of personal preference. Steve Larson claimed to be riding a very slack seat angle at this year's Hawaii IM (though he really didn't know the numbers). When the bike was inspected, it was found to have a fairly steep ~76 degree seat angle. One thing to remember, if you're moving the seat forward, you also need to raise it to maintain the seat-to-pedal distance.
re: Are steeper geometry tt bikes faster - ???TriBuddha
Jan 3, 2002 5:34 PM
I have been where you are going, and do not agree with you on one thing and that relates to cadence as you put seat further back, cadence does suffer and more is not better (again depending on body), there is a point where my cadence not only suffers but so does the power output. Best thing to do is play with all the variables on a computrainer, or other power and cadence measurement device if you can. Another thing is make sure you are riding at race pace at some point in the experiment, b/c your position will adapt to the most efficient position when you put it under some stress. Also if you are preparing for a long distance tri where aerobars are going to be used most of the time I suggest that the bike be set up for that race and all experiments are done with aerobars and not hoods or drops. Many times I have heard my training partners say they are more comfortable on their hoods, well sure that was how the shop set you up in the first place!

I did this with a computrainer with my wife taking pics at various points from various positions and it was clear that I started to creep forward as the intensity increased, if you check the pics of Larsen in Hawaii you will note how far forward he is perched on his seat. Now this is personal to me and has taken me a ton of experimenting to figure just a few things out. I also ride a road bike with Syntace clip ons, and found that given my small frame I can get into a forward position easily without too much jigging with the set post.

Have fun playing