Tri bike fit: short and aggressive or long and higher?
pianoman
Posts: 706
I've sat on a few TT bikes recently and noticed how different each of the them feel, and also how much lower you can get on them than even my most aggressively-positioned road bike. One thing that's come up many a time is the issue of sizing. Apparently if I don't size down very much from my road bike then I'll only make the TT bike work with a higher arm rest height. Conversely if I cut the toptube back I can get lower. But both positions promote a flat back if done correctly, right? I'm asking because at the moment my TT bike is both a bit short on length AND rather high at the headtube. So, which aero position is favoured? A shorter bike with a lower position (more bunched) or a higher one, but one which stretches the body out more? At the moment I feel neither stretched out nor particularly low meaning that the bike feels very small indeed.
I do like to ride very steep so was thinking of a 78 degree angled bike such as the Speed Concept you see.
Any thoughts?
I do like to ride very steep so was thinking of a 78 degree angled bike such as the Speed Concept you see.
Any thoughts?
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Comments
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Why the desire for a 'flat' back? It's not necessarily more aero than s 'curved' back.
You need to visit a shop and get them to fit you. Stack and reach are good measurements to know, and will help direct you to the appropriate frames. Some suit a tall/short frame, others (like me), will favour a longer/lower frame. I have long torso, short legs, hence the frame choice for me.Start with a budget, finish with a mortgage!0 -
Well, I am like hopper1 (long body but short legs particularly short upper leg) and have not had any problem with flexibility in 10 mile TT's and bike legs of triathlon that have gone up to 20 miles. I'm thinking maybe to go with something longer, go as low as I care for TT's and then still have the facility to raise the bars in line with ageing/race distance. If I go with something smaller I won't be able to go high at all which could cause its own problems further down the line?0
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It's easier to make a small bike bigger than a big one smaller - adaptive training should mean that over time you can work on your flexibility and power output. An adjustable stem is a simple fix to help with going 'longer'. For 10 mile TT's my bike was set-up extremely short and deep but was very painful after about 20 miles and positively purgatory when I rode a 50. I don't get the long headtube argument for TT's bikes - smacks more of marketing that scientific fact.Make mine an Italian, with Campagnolo on the side..0
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It is definitely better to go small rather than large. I am 5'11" and ride 56cm road bikes with 55cm top tubes. I converted one to TT use by fitting full aero bars and shoving the saddle as far forward as it would go. Not a total success but it told me where I wanted to be. Now have a PX Stealth medium, 53cm top tube and 51cm seat tube. Saddle is still pushed forward (tip 2cm behind BB) but the bike is much more comfortable. I have done a 60 mile shake down ride on it. Also in the last 25 of the season I did my fastest time since 2002.Monty Dog wrote:It's easier to make a small bike bigger than a big one smaller - adaptive training should mean that over time you can work on your flexibility and power output. An adjustable stem is a simple fix to help with going 'longer'. For 10 mile TT's my bike was set-up extremely short and deep but was very painful after about 20 miles and positively purgatory when I rode a 50. I don't get the long headtube argument for TT's bikes - smacks more of marketing that scientific fact.
My basic system was to take my road position and revolve it forward round the BB while keeping the same hip angle, Then sorting the bars out. I am using the same stem (120mm). Pic is on old bike. I am a bit lower on the new one.
http://martin.photium.com/rrr26280
