I've been watching triathlon videos lately and I couldn't help but notice that, with the exception of Ironman Competitions, only road bikes and not time trial bikes are being used. Is there any reason for that?

  • Not mentioned (so far) in any answers is Tris are, well, tris - there are three sports involved. Competitors need to optimize performance across three disciplines, for many the effort optimizing cycling on a TT bike is worth less than putting it elsewhere.
    – mattnz
    Jul 15, 2019 at 20:25
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    For those who were not familiar with "time trial bikes" (like myself), here are wikipedia links for the three types: Road bike, Time trial bike, and Triatholon bike. Jul 17, 2019 at 16:30

5 Answers 5


The OP linked 4 videos, the first 2 videos were long-course Ironman races, where time trial (TT) bikes were used, while the latter 2 videos were of short-course draft legal races where road bikes were used. In the latter two videos the competitors were either pros or elite amateurs. These individuals typically have multiple bikes and would be using a TT bike if it was the right tool.

Originally, all triathlons used to have a no-drafting policy, which made optimizing your personal aerodynamics critical. Hence the rise of TT bikes in the early history of triathlons.

Relatively recently drafting has been made legal in many short track triathlons, making TT bikes both dangerous and not suitable for the format. When you have drafting you essentially have a road race, which a road bike is the right tool. Quick handling is key as you need to be able to maneuver and keep your front wheel within 2-6 inches of the bike you are drafting in order to get the full draft effect. You also need to be able to accelerate, brake, and change direction quickly to close gaps and respond to group dynamics. Groups can at times move incredibly fast, 65 kph on the flat is not uncommon for pros or elites.

In contrast, Ironman events still have no-drafting rules in place making TT bikes the right tool as its about individual riders against the wind and not responses to group dynamics.

NOTE: the answer is intended to address the races explicitly highlighted by the OP, not all world wide triathlon events, nor the large array of amateur races where participants may be balancing a number of considerations (e.g., cost).

  • 4
    The first 2 videos linked by the OP were for long-course Ironman races. The latter 2 videos were for short-course draft legal races.
    – R. Chung
    Jul 16, 2019 at 4:45
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    Ahhh! That was the missing piece in my puzzle!
    – Eyad
    Jul 16, 2019 at 5:12
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    How recent were these rule changes? Any links or references? I haven't done a tri in 10-ish years but "way back then" I can't remember there being any draft-legal races. I guess things change with the times!
    – dwizum
    Jul 16, 2019 at 13:57
  • @dwizum at least in the USA, draft legal races are still very rare at the amateur level. However, at the elite level, ITU sanctioned races (notably including the Olympics) have been draft legal going back at least to triathlon's Olympic debut in 2000. Why ITU and IOC decided to make pro races fundamentally different than their all-comers counterparts, I will never understand... Jul 16, 2019 at 21:23
  • @JoshDoebbert ok then I guess maybe little or nothing has changed after all, given that my experience is amateur events in the US.
    – dwizum
    Jul 17, 2019 at 12:47

Triathlon and time trial bikes are quite expensive and not wonderful to ride on open courses, hills, and in groups (in other words, general cycling).

So, if you're not so serious about triathlons that you're willing to spend several thousand dollars on a bike that will see relatively little use, you'll likely be content with your existing road bike whose handling and fit works well with your body and riding style.

  • 2
    I have limited personal experience, but based on people I've talked to it takes dedicated training on the time trial bike to become good/experienced enough for the bike to be a worthwhile investment. So there's the training cost to consider in addition to the monetary cost.
    – DavidW
    Jul 15, 2019 at 17:52
  • that's a great point @DavidW
    – Paul H
    Jul 15, 2019 at 17:58
  • All of the videos were of either pro's or elite amateurs. The road bikes in the videos were carbon with deep section carbon wheels, easily over $6K. So these are serious competitors who would have been using a TT bike if it was the right tool.
    – Rider_X
    Jul 15, 2019 at 19:21

In addition to Paul H's answer, there are several different triathlon distances from sprint to full iron man. In shorter races with hilly bike courses, or where there are many tight turns a regular road bike may be preferable.

  • Drafting is also allowed in many short course races. Very different type of racing.
    – Rider_X
    Jul 15, 2019 at 19:21

Another lesser point is money - sport costs, and a triathlon is essentially three distinct sports in one.

The bike is an expensive item, and so making use of what you have is a perfectly good solution. For some competitors, that will also be their commuter come Monday morning.

I've even seen Mountain Bikes used in a triathlon, with road tyres and locked out suspension.


My own observations do not agree with yours. In the Gulf Coast 70.3 this year there were a fair number of people on road bikes and even some on hybrids. There was one lady with a basket on her bike.

This past weekend, and many event like it, I attended an event where a they had a Sprint that had and Olympic distance at the same time through MultiRace. As usual there were many high end triathlon bicycles. Despite it being a no draft race, a road bike might be more suitable as the roads are really rough. It makes it difficult and possibly dangerous to remain in aero the whole time.

If you go to just about any event you will see a full spectrum of bicycles. Many, for cost reasons do like I did and have a road bike with clip on aerobars. Its very cost effective. Finding a used road bike is far easier then finding a used tri bike.

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