Note that Boardman Bikes is one of my sponsors
TT-bike or road bike for Norseman, which bike to choose? That question has been discussed thousands of times. A few days ago Norseman had a live session with their sponsor Intersport where they discussed the topic together with last year winner Lars Christian Vold.
Basically, the answer is, if you have performance in mind the TT-bike is the better choice. That is Lars Christians view, Lars Petter Stormo (winner 2016) and my own view.
However, if you take an aerodynamic road bike, put on aerobars and get an identical riding position as your TT-bike, would the answer still be the same? Even as a “Messiahs” for the TT-bike, I honestly am not certain of the answer.
My Boardman TTE Signature is aerodynamically better than my AIR 9.9, but how much better? For the fun of it, let’s estimate 15 % better aerodynamic performance in favour of the TTE. Since the total aerodynamic drag from the bike and wheels is only about 20 %, the gain will be 15 % of 20 %, which is equivalent to a total gain of 3 % increase in aerodynamic performance. In regards to time that would be translated to roughly 3 minutes and 22 seconds, over a flat 180 km course*. The Norseman course is, as we know, not flat. The AIR 9.9 is just over 1 kg lighter than the TTE. Would that decreased weight give an overall positive performance? That is a really good question! 1 kg less weight in the more than 50 km of uphills with just under 5 % average incline will, in theory, save you a bit more than 2 minutes.
The only way we can know the fastest setup is riding the Norseman course twice with identical conditions. And repeat the procedure to account for the potential conditions. In reality that is impossible to do since the Norseman course never will have identical weather conditions to conduct the test. The best way to give the most accurate answer is to test both of the bikes in a wind tunnel, and then calculate their performance in the hilly Norseman course.
If everything goes according to schedule I will be able to give the TTE a “run for its money” against the AIR 9.9 in the wind tunnel at the Boardman Performance Center, which opens soon. That would give me the numbers that I believe will give you the best possible answer to the monumental question; TT-bike or racer for Norseman? In the meantime, we could have a look at my AIR 9.9 and take a guess. Note that I, of course, will be mounting on aerobars.
*The calculations are done in the Gribble calculator with the following factors:
- Weight of rider: 75
- Weight of bike: 8 kg
- Watts: 200
- CdA of the rider with TTE: 0,26
- CdA of the rider with AIR: 0,268
- Gradient: 0 %
Allans triatlonverden 
Är det en liknande setup som Brownlees körde på förr?
Jepp, foruten om fremgaffelen som hadde utenpåliggende bremser på Brownlee sine.
HI Allen,
Have been enjoying your blog (translated to English) and some of your research.
Have you had the opportunity to do any 9.4 vs TTE tests?
I only «race» olympic distance duathlons so am investigating if it’s best to have an excellent aero road bike, or a cheap road bike for training and a great triathlon bike for racing. Was hoping you had some comparison tests from experience as to if it makes much difference in 2018 🙂
Many thanks.
Hi Sam. I have not done any «scientific» tests yet, but have ridden a lot with both the TTE and AIR with identical position. The AIR with clip-ons (or similar aerodynamic road bikes) is a truly good solution. I believe I could have used it in a race without the big loss of time. Will not speculate how much without doing the tests but not much.