Triathlon - Tri-bike sizing?

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HJR
05-17-05, 08:50 PM
Hi all,

I have been considering buying a Tri/TT bike and I was speaking with a pretty knowledgable acquitance the other day and he mentioned that for a Tri/TT bike, a person should be on a "smaller" frame in relation to their road bike, otherwise they would be too stretched out. For example, I ride a 55 or 56 road bike. I could, if needed, get down to a 54, but because i need a slightly longish top tube (a 54 would require a 130 stem), I've stuck with the 55 and 56's. He recommneded that I should be looking at 54or smaller for a Tri/TT. Does this sound right? Even if it is from the same manufacturer as my road bike?

Thanks in advance, for any and all help.

HJR

Gonzo Bob
05-18-05, 11:17 AM
Well, maybe, maybe not. For most people, their tri-bike should have a shorter head tube and a shorter top tube than their road bike to allow for a lower, more forward position. So in that sense, you want a "smaller" tri-bike. However, for most tri-bikes, the frame size is a "virtual" size. The "54" in the size is often not the actual measurement of the seat tube. It is a number that basically means "if you ride a 54cm road bike, this is corresponding tri-bike size for you". My road bike is a 55 and has a head tube of 14cm and a top tube of 56cm. My tri-bike is a "55" and has a head tube of 10cm and a top tube of 54cm. So the "55" tri-bike is already smaller than my road bike. No need to go any smaller in this case.