I'm new here and if this has been covered, sorry. But I just read a thread that led me to believe it hasn't been.
I read alot of comments like "the fastest TT riders in the world ride slack angles" referring to UCI riders who are limited to how far forward the nose of the saddle can be.
I beg to differ. Yes the UCI rules limit saddle steepness. Besides the fact that many riders chop the noses off their saddles to allow the rear of the saddle to be farther forward (see http://www.cervelo.com/wallpaper/1/w011_800.jpg), the actual position of the saddle is somewhat irrelevant.
It's where the guy sits that matters. Take a look at Zabriskie riding the fastest TT ever recorded ( http://www.cervelo.com/wallpaper/1/w008_800.jpg ). Things to notice: He has the seatpost set in the 78 deg position. More importantly, the rear of his butt lines up w/ the FRONT of the seatpost. Draw an imaginary line from the bb to the virtual center of where he is sitting, and it looks like something close to 90 deg.
I have a P3c with saddle in similar position (w/o nose removed the nose is directly over the bb on 61cm frame = 78-80 deg). I don't care what the UCI measured - he is riding much steeper than 80deg.
You may also notice that his drop from saddle to pads is something around 9-10", and he isn't a very big guy.
I propose that the experienced rider will automatically shift far enough forward on the saddle to set hip angle at 90 deg or greater, regardless of actual frame geometry (assuming the cockpit is long enough). You can find countless pictures of UCI riders riding this way, unless they don't have much drop from saddle to pads. There is a picture somewhere of former UCI rider Kai Hundertmark (sp?) in the Ironman riding a p3 too - guess where his butt is? In front of seatpost.
Something else about UCI riders. When they ride hard in the drops, where do they sit? On the nose. Same reason - to open up the hip angle to compensate for lower torso.
Bottom line, not that many guys actually ride a slack angle if they are low and aero, UCI or not.
TK
ttbikefit.com
I read alot of comments like "the fastest TT riders in the world ride slack angles" referring to UCI riders who are limited to how far forward the nose of the saddle can be.
I beg to differ. Yes the UCI rules limit saddle steepness. Besides the fact that many riders chop the noses off their saddles to allow the rear of the saddle to be farther forward (see http://www.cervelo.com/wallpaper/1/w011_800.jpg), the actual position of the saddle is somewhat irrelevant.
It's where the guy sits that matters. Take a look at Zabriskie riding the fastest TT ever recorded ( http://www.cervelo.com/wallpaper/1/w008_800.jpg ). Things to notice: He has the seatpost set in the 78 deg position. More importantly, the rear of his butt lines up w/ the FRONT of the seatpost. Draw an imaginary line from the bb to the virtual center of where he is sitting, and it looks like something close to 90 deg.
I have a P3c with saddle in similar position (w/o nose removed the nose is directly over the bb on 61cm frame = 78-80 deg). I don't care what the UCI measured - he is riding much steeper than 80deg.
You may also notice that his drop from saddle to pads is something around 9-10", and he isn't a very big guy.
I propose that the experienced rider will automatically shift far enough forward on the saddle to set hip angle at 90 deg or greater, regardless of actual frame geometry (assuming the cockpit is long enough). You can find countless pictures of UCI riders riding this way, unless they don't have much drop from saddle to pads. There is a picture somewhere of former UCI rider Kai Hundertmark (sp?) in the Ironman riding a p3 too - guess where his butt is? In front of seatpost.
Something else about UCI riders. When they ride hard in the drops, where do they sit? On the nose. Same reason - to open up the hip angle to compensate for lower torso.
Bottom line, not that many guys actually ride a slack angle if they are low and aero, UCI or not.
TK
ttbikefit.com