View Full Version : how different is your TT position from your road position?
Phatman
01-21-07, 08:09 AM
well, the topic title explains it mostly. I'm trying to decide on a frame size for the tt bike I'm building up. I will mostly be doing shorter TTs, in the 30-40 minute range, if it matters. I'm thinking it might be better to have my seat in a position closer to my road position since I want my TT fitness to translate well to road racing breakaway/long climb ability. I want to hear your thoughts.
DrWJODonnell
01-21-07, 08:25 AM
General rule of thumb. Your TT bike should have a top tube measurement of about 2cm less than your road bike.
In general, it will not be good to have your seat position as far back as your road position unless you have the flexability to touch your forehead to your kneecaps without straining. A more forward seat position lets you generate more power in the aero position (decreases the angle of the hip).
Metallica used to be a good band.
Those are my thoughts.
Metallica used to be a good band.
A long, long time ago.
cycle17
01-21-07, 08:57 AM
I ride a 56cm (trek) road bike, but my TT bike is a 55cm (the company calls it a 57). The positiing is very different on a true TT bike. I'm directly over the pedals, the seat is much farther forward and your weight is distributed much differently.
Generally, two cm shorter is about right, but it would depend on your body type. And as I mentioned above bike companies don't all size their bikes measuring from the same points.
Stallionforce
01-21-07, 12:29 PM
Basically, you have to size your TT bike according to the top tube length. It means trying out a few bikes, because measuring your torso to fit the top tube won't work; it has to do with flexibility as well.
Hope you enjoy your TT season! I just got a P2 and am looking forward to seeing some improvement just from position.
check out the tri/tt fit calculator (http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO&INTRO_LINK=NOREDIR&SITE.CODE=TRI) at competitive cyclist.
Road frame = 58cm, TT frame = 56 cm
Road saddle-to-bar drop = 5 inches, TT saddle-to-elbow-pad-drop = 6 inches
TT bike saddle is slightly more forward on the rails and sloped slightly downward.
--Steve
Phatman
01-21-07, 02:21 PM
Road frame = 58cm, TT frame = 56 cm
Road saddle-to-bar drop = 5 inches, TT saddle-to-elbow-pad-drop = 6 inches
TT bike saddle is slightly more forward on the rails and sloped slightly downward.
--Steve
zimbo, we seem to be about the same size, I ride a cannondale with a 73 degree seat tube angle, 57.5cm top tube. what is the seat tube angle on your TT bike? I'm looking at a quintana roo with a 56.5 degree top tube and a 74.5 degree ST angle.
nitropowered
01-21-07, 04:01 PM
I ride a 56 c-c road bike, and my TT bike is 54 c-c. My TT bike is actually a road frame with standard "road" geometry. My seat on the TT bike is as far forward as rules allow.
zimbo, we seem to be about the same size, I ride a cannondale with a 73 degree seat tube angle, 57.5cm top tube. what is the seat tube angle on your TT bike? I'm looking at a quintana roo with a 56.5 degree top tube and a 74.5 degree ST angle.
Seat tube angle is 76 degrees. It's a Motobecane Nemesis.
--Steve
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