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Road v TT Frame Difference

by KirinChris
Tue, Jun 14, 2011 05:02
3

Never having ridden TT or Tri bikes much, is there a major difference with road frames ?

I know the geometry is slightly tighter but would it make a big difference to a rider ?

The reason I ask is that a young chap here has been into triathlon and got himself a new Planet X Stealth Pro Carbon TT/Tri bike less than a year ago.

Now he has seen the error of his ways 3 and decided he should do more general road riding. I think that's a good idea, he's far too young to be specialising in TT style riding I think.

He was talking about getting a new bike - Planet X also have some big discounts on their road frames at the moment and he's thinking of the Nanolight Carbon Fibre (there's a distributor here, hence the Planet X interest). He hasn't got a big budget and he'll lose on his current bike if he sells it.

I suggested he just take his Stealth frame and convert it with some road bars and gearing. Seems the cheapest and easiest option.

But someone has told him that TT bikes will work out his quads but not his hamstrings and he should get a proper road frame.

I find it hard to believe a few degrees of seat tube angle makes that much difference, but as I haven't ridden TT or Tri bikes much I don't really know.

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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3 comments

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monty dog | 12 years ago
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TT frames have a shorter toptube for a given size in comparison to a road frame, therefore you'll need to look at both a seatpost with extended layback to compensate for the seattube angle plus a slightly longer / riser stem to get a more typical road position for the bars.

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cat1commuter | 12 years ago
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You may be able to negate the steep seat tube angle by sliding the saddle back on its rails. Many riders will err on the smaller side when choosing a TT frame to get a shorter head tube to put the aero bars in the right position. ie: the vertical drop from the saddle to the top of the head tube is larger than on a road bike. You may therefore need to get a stem with more angle (such as +/- 17º) and use it flipped up to put the bars in a better position for all day riding.

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BrakeNoodle | 12 years ago
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The steeper seat tube angle of a TT bike opens up the hip angle and takes the pressure of the hamstrings. The net result is that it makes it easier to run off the bike. I've heard that it can make as much as 20mins difference for run splits on an Ironman distance race.

A TT frame also has greater aerodynamic benefits for the rider position and puts them directly over the bottom bracket allowing more power to be put through the pedals when seated.

Road bikes however have a clear advantage on technical and more sporting courses and also in draft legal races. The other issue is one of convenience and cost. If you can only have one bike then go for versatility and choose what you would get the most out of.

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