TT Bike Build . . .
Discussion
now I am the very first person to know how lucky I am - I have two beautiful bikes - a Colnago CLX based racer and a 753r Framed Peugeot racer (that I have had since new) - both kitted out with Campag Record 08 etc and I love riding both of them and I built them both.
All of a sudden I have a massive urge to go TT'ing so I would like to convert my Peugeot into a TT bike and this is what I am thinking I will have to do . . .
Bear in mind that the Peugeot has traditional geometry (not sloping) and I have a 30" inside leg and its a 52cm frame.
Get a decent set of TT wheels
Change the drop handlebars for some aero ones + change the brake/gear controls etc to suit
Might have to change the gearing too - currently on a compact chainset with 11-21 gearing
What else would I need to do to build a speed-machine - is it possible - I just have to do it!!!!
khushy
All of a sudden I have a massive urge to go TT'ing so I would like to convert my Peugeot into a TT bike and this is what I am thinking I will have to do . . .
Bear in mind that the Peugeot has traditional geometry (not sloping) and I have a 30" inside leg and its a 52cm frame.
Get a decent set of TT wheels
Change the drop handlebars for some aero ones + change the brake/gear controls etc to suit
Might have to change the gearing too - currently on a compact chainset with 11-21 gearing
What else would I need to do to build a speed-machine - is it possible - I just have to do it!!!!
khushy
Edited by khushy on Tuesday 19th August 13:14
If you're keeping the road geometry, be careful about fitting proper aero bars. Your body might be too scrunched up meaning you won't be able to breathe properly. The forward geometry is very important to achieve this position properly.
One way to rotate your position on a road bike is to get a forward facing seat post, which can effectively change the geometry for TT.
One way to rotate your position on a road bike is to get a forward facing seat post, which can effectively change the geometry for TT.
aha - so a TT bike has a steeper seat tube angle - maybe its not such a great idea as with both my road bikes I am most comfortable with a really short stem!
After having a professional bike-fitting recently - both my bikes were said to be optimal the way I had set them up apart from the seat height which was a tad too low - everything else - even after the computer analysis and video was perfect!
Maybe a TT frame is the way to go!
Will look into this further before committing.
khushy
After having a professional bike-fitting recently - both my bikes were said to be optimal the way I had set them up apart from the seat height which was a tad too low - everything else - even after the computer analysis and video was perfect!
Maybe a TT frame is the way to go!
Will look into this further before committing.
khushy
Edited by khushy on Tuesday 19th August 22:19
jacobyte said:
If you're keeping the road geometry, be careful about fitting proper aero bars. Your body might be too scrunched up meaning you won't be able to breathe properly. The forward geometry is very important to achieve this position properly.
One way to rotate your position on a road bike is to get a forward facing seat post, which can effectively change the geometry for TT.
Another option is to fit a 26in front wheel. This will change the steering angles etc, however I suspect your Peugeot may have slightly laid back steering geometry so it may help to sharpen things up a bit.One way to rotate your position on a road bike is to get a forward facing seat post, which can effectively change the geometry for TT.
I built a decent TT bike years back using an undersize frame and a forward seatpost. Got a very good aero position without limiting my physical ability.
There's no reason not to use a 'road' frame to achieve a good aero position if you want to - the right combination of bars, stem and seatpost will get you there.
The chief difference you will see with a TT-specific frame, however, is in the shorter chainstays, which pull the rear wheel forward under you and undo some of the handling compromises that the forward weight distribution causes.
The aim is to get your chest horizontal, with your arm bones bearing your weight rather than your arm and shoulder muscles; you can't do this just by fitting lower bars, though, as you won't be able to breathe and your thighs will hit your stomach: you need to move your body forward as you lower it in order to open-up the angle at your hips.
You'll struggle if your bike fit is based on the knee-over-pedal dimension, however, because that goes out of the window; you need to think instead in terms of your hips being on a radius from the BB and rotating yourself forward on the frame whilst keeping that radius constant.
This series of articles is worth reading before you decide how to go about it.
The chief difference you will see with a TT-specific frame, however, is in the shorter chainstays, which pull the rear wheel forward under you and undo some of the handling compromises that the forward weight distribution causes.
The aim is to get your chest horizontal, with your arm bones bearing your weight rather than your arm and shoulder muscles; you can't do this just by fitting lower bars, though, as you won't be able to breathe and your thighs will hit your stomach: you need to move your body forward as you lower it in order to open-up the angle at your hips.
You'll struggle if your bike fit is based on the knee-over-pedal dimension, however, because that goes out of the window; you need to think instead in terms of your hips being on a radius from the BB and rotating yourself forward on the frame whilst keeping that radius constant.
This series of articles is worth reading before you decide how to go about it.
To be honest you can pick up some lovely TT frames on ebay for not a lot, I tried to go down this route with a TT frame but "roadise" it, and failed to be honest, it was never going to be comfortable so I sold it again, but from memory I paid something like £60 for it and sold it for about £250 (I fell very lucky with a buyer) that was a handmade frame made of 753 steel from memory, 650c front wheel mavic cxp33 rim running a mavic hub that was the smoothest hub in all history.
But about £100 should see you a nice frame, possibly with a front wheel. Then just add your bits on as you go and you have a nice bike.
But about £100 should see you a nice frame, possibly with a front wheel. Then just add your bits on as you go and you have a nice bike.
If your going to compete you need to understand UCI rules and where physical limitation comes in.The set up length and distance behind the bb have a maximum allowance in the rules(tri rules are different)
You want to make sure you dont change your cranking angle(hip angle)that you have been pedalling as you might as well go back to cycling a fresh if you do.
Put simply, you rotate your normal riding position around the bb to try get yourself as small a position to punch a hole in the air against areodynamic drag.This is not always a flat back(look at Cancellara)
Once you've rotated your position you will find you slip past the uci allowance on the seat and you will end up on the rivit at the front.
Arms are too varied to make standardisations other than rest your body on them comfortably.Someone with experience would need to see you sat in your rotated position to judge.
Areo is king,drag is the problem, it all adds up.I'd not worry too much about the bike and in my opinion these matter more, position, tyres, their pressure, helmet, wheels, clothing and more than anything else your optimum physical condition and how you extract it for the given distance.The frame is less than one single percent!But they look cool and can give you a mental edge(i am wind tunnel experienced
You want to make sure you dont change your cranking angle(hip angle)that you have been pedalling as you might as well go back to cycling a fresh if you do.
Put simply, you rotate your normal riding position around the bb to try get yourself as small a position to punch a hole in the air against areodynamic drag.This is not always a flat back(look at Cancellara)
Once you've rotated your position you will find you slip past the uci allowance on the seat and you will end up on the rivit at the front.
Arms are too varied to make standardisations other than rest your body on them comfortably.Someone with experience would need to see you sat in your rotated position to judge.
Areo is king,drag is the problem, it all adds up.I'd not worry too much about the bike and in my opinion these matter more, position, tyres, their pressure, helmet, wheels, clothing and more than anything else your optimum physical condition and how you extract it for the given distance.The frame is less than one single percent!But they look cool and can give you a mental edge(i am wind tunnel experienced
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