Choosing a Time Trial Bike

Hi team,

After the great responses from my other post last week. I have decided to start the process of either buying a TT Bike. or building one up (I have access to a good workshop and really enjoy mechanical projects like this)

Currently I will use my road bike with clip on aero bars for awhile for training and any initial races.

The plan is going to be mid volume SSB 1 + 2 - Sustained Power Build + 40K TT

I have no races planned yet as I have to figure out how the system works.
I live in Bergen Norway, if anyone has any information.

I have started to research and read about how to choose a frame size and style and I have some initial questions.

  • Would you recommend a bike fit prior to choosing a frame? I keep seeing ‘stack and reach, long and low, narrow and tall’ coming up.

  • How do older frames compare to new frames. Would an older model that fits your size better than a modern frame be the best option or does a new free (better technology, materials, etc.) trump this?

My focus is on the training and the bike will be a long term project as I am so new to time trial and have plenty of time.

Any and all advice you have would be greatly appreciated.

Thanks for your time.

Aerodynamics is obviously the point of a time trial bike, but that vast majority of the drag comes from you and your physiology and bio-mechanics. One TT bike can be super aero in a wind tunnel by itself, and more aero than another TT bike, but that doesn’t mean that when you are on that bike it will still be more aero. Fit is the key point and is even more important than on a standard road bike.
A really good fitter will be able to work out what is your best theoretical position in terms of the balance between power output and aerodynamics, and be able to work out what bike (hopefully bikes plural) gets you closest to that. An older cheaper aluminium TT bike can end up being massively more aero as a whole package than a new expensive carbon windtunnel tested super bike if you can get into a great position on it, and your position on the super bike isn’t so good.
Basically, fit trumps all other concerns as it has by far the biggest impact on aerodynamics.

Another thing worth considering is that your ideal TT position will change massively as you start to train more and more in that position. As an inexperienced TTer you probably won’t be able to get super aero without sacrificing massive amounts of power, but as you develop you will be able to get more aero without sacrificing so much power. This can mean that a bike that was a bad fit for you initially becomes a good fit (and, vice versa, a bike that fit well originally becomes sub-optimal). Unless you have very deep pockets, this is a good argument for keeping things cheaper for your first season and saving any massive investment for when you are more adapted.


I’d echo paul about fit being crucial.
The other thing to note is that with modern integrated TT bikes, it’s much harder to adjust the position significantly using different stem, bars etc. so you really need to sort out your fit before you start buying bikes (assuming you want an integrated bike and just want to buy one!).

On the terminology front:
Stack and Reach are measurements that you can do on any bike - they are the vertical distance from the BB to the top of the head tube and the horizontal distance respectively. I’d suggest they might be more useful for road bike fitting than TT bike, as TT bike seat angles can be quite different, and some offer a large adjustment factor in the seat clamp.
The long+low or tall+narrow stuff you see coming up are essentially different philosophies on how to best position the rider to minimise drag. To a certain extent, the best approach depends on the body shape, flexibility and strength of the rider. Long and low used to be dominant, and some of those bikes are still really good, but you should probably just go find a fitter who really understands TT (tri fitters are likely to be good but might optimise a bit more for comfort) and take his advice.

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Worthwhile reading:

Stack & Reach info from the man that set the measurements and coined the terms:

Choosing a bike based on Stack & Reach:

Stack & Reach Database for bikes:

Pad XY (The real measurements that matter most for a Tri/TT fit):


+1 on figuring out fit first, so that you can get a bike that not only fits initially but has plenty of room for adjustment as you get used to TTing and your position evolves. Assuming there will be a triathlon club near you that might be a good place to start in terms of finding a recommendation for a good local fitter.

In terms of bikes, there are some very good older frames out there - something like a Cervelo P3 for example can be built out so that it gives very little away to a modern superbike (assuming you fit well on the P3). The trend over the last few years has been ever-increasing integration, particularly around brakes, stem and head tube and bars. Problem is this level of integration has brought aero benefits but in some cases at the cost of adjustability and ease of maintenance, particularly on some of the earlier superbikes (new ones are better but expensive). If you go secondhand make sure you get something that has plenty of adjustability and isn’t a compete PITA to work on.


Agreed. I went with the “older” Shiv (tri version) for my new bike, partly because it uses a standard stem, more typical brakes and is all-around easier to work on than the newer super integrated bike. I do give up some on the aero, but not enough to matter in my small racing. I suspect it only is an issue for top level age groupers and above.

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+whatever on getting the fit first. You can post on Slowtwitch to find good fitters in your area as not all fitters are created equal.

Also, I don’t think I saw it mentioned but check the rules on the type of TT you’re looking to do. There are a lot of TT bikes made for triathlon that are not compliant for sanctioning bodies like UCI.