I’ve been doing sprint triathlons for a couple of years now. I’m far from being front of the pack, but am a bit ahead of the middle of the pack. I did one last Sunday and came 8th out of 56 in my age cat, which I was happy with.
I’m not great at any of the 3 disciplines, but the bike leg is frustrating because the people zooming past me are all on TT bikes. I’m on a Giant TCR road bike with aerobars.
I’ve now got approval from the boss to get a TT bike. The Cervelo P-series looks like good bang for buck. What I’m really interested in is how much faster I can expect to be? From what I’ve read, the position on the TT bike also keeps your legs fresher for the run?
My FTP is around 260-270 (72kg) and I normally ride at about 230-240 during the bike leg. Sunday’s 20k bike leg was just over 33 mins. The best guys are all closer to 30 mins, some faster.
Probably worth adding, I have some very rough datapoints from looking at the power/speed data for people who train at the same local velodrome as I do and the TT bikes look way faster. I know there are lots of variables but whereas my laps at 260W might end up around 38-39km/h, a guy on a TT bike was over 40km/h for similar power. His overall ride averaged 37.5km/h for just 213W.
Another time I was riding some way behind someone on a TT bike, matching his speed. His data showed him doing 25-30W less than me at the same speed.
I’ve found that often your perception of what happens in a race is a little off.
For example, are you in the top 10% of swimmers, so you are heading out on the bike earlier?
I would download the results of your AG and see where you stack up just on bike split.
You can upload one of your bike splits to best bike split, then change to a TT bike, and then that will give you a clue in terms of numbers, I would think 25w at reasonable speeds seems about right, when I tested my 44.5w gain (at 45kph) would save 69s over 10miles (via 0.038 cda improvement) so you might take a minute off.
The thing about TT bikes is there zero compromise in terms of fit in trying to fit around clip on aero bars, plus then you can do a few other fit things, like forward saddle position, to as you say, open up that hip angle for running.
I’ve done draft legal and non-draft, in terms of the run I do feel my TT bike make running better, but then draft legal is raced differently and theres surges etc so its hard to say for sure.
You’ll likely be faster, how much depends on the course and your riding skills/aero position on tri bars vs TT bike. My own experience of about the same weight/power for a sprint; maybe a few minutes difference.
If it matters or if it is a worthwhile investment of your money depends on you
I don’t know how accurate it is but it didn’t seem too far off for me as I upgraded, the rule of thumb I was told. On a 10mile TT its supposed to be 30s roughly per upgrade. Road Bike>Clip Ons>TT Bike>Deep Sections > Disk. Even now I go round our local 10miles (16.1km) TT on a TT bike compared (deep section front, disc rear) circa 2 mins faster than I do in a road bike TT. At a finger in the air guess, I think a TT bike could be at least 1.5-2mins faster for you @moonman
ok i have to preface this is a flex lol i did a sprint tri with my wife recently, she did swim and I did bike and run (which I crammed the training in two weeks, enough to not get sore). I did it on my road bike, no clip ons, and was the 5th fastest among all sprint tri competitors, was good for the ego when I feel really average normally.
all this to say, I have thought of maybe continuing in individual duathlons in 2025 and getting clip on aero bars and a zero offset seat post and see how I do with those. I’d love to actually try a TT bike but I don’t think anyone I know has one I can borrow to try and it seems like one of those things, like my former MTB, which would sit in my basement and not get a ton of use
Very tough to generalize, since it’s not the bike so much as the position you adopt on the bike. How slippery you are on the tri bike is really up to you. I ride a Cervelo S5 road bike (sometimes with clip-ons) and a Cervelo P3X tri bike. I’m generally 1 to 2 mph faster on the tri bike for the same power, and my tri bike position is very relaxed- optimized for all-day comfort rather than speed. I’m guessing I could coax another mph or so out of the position if I was willing to sacrifice some comfort.
In my last tri similar to what you described, I averaged about the same speed as you but on power in the 190W-200W range on the P3X.
Personally, I think running off the tri bike vs road bike is all placebo / mental. Lot’s of talk about “fresh legs” but I’ve never really seen data that supports the idea. If you believe you feel better, then you really do feel better whether it makes a physiological difference or not.
I think you make good points, we used to 10-15 years ago argue that the aero position keeps your running muscles fresher, which I agree is placebo. I think that was the selling point for our significant others to buy the tri-bike.
The point you make about going the same speed with less watts is truly the key point, same/more speed with less effort keeps you fresher for the run.
Yeah then I’ll agree with the others and say that - with training in good position - 1-2 minutes are up for grabs. I’d pull the trigger now and get the tri bike on the trainer asap before next season starts.
31 mins is pretty good on my local lumpy sprint tri, but I need to pick up a vast amount on the run to podium. I used a new roadie for the handling.
id guess your cda might improve by 0.03 to 0.05 relative to roadbike with aerobars with something like 8 watts per 0.01 cda change i.e. 24 to 40 watts. Id expect this translates to something like 1.2–2km per hour faster at the same power. (all just estimations)
Where id caution is whether you can hold the same power - its very common to see lower output on tt bike so you may end up with less speed gains than expected. I think the points about run legs being fresher are the opposite - in my experience - more aggressive position will make run legs less fresh.
Make sure to tick off things like tyres, tubes, helmet and trisuit in your optimisation…
Probably lots of opinions but Contintental GP5000 seem to be a good balance between speed and puncture resistance. Latex tubes over butyl are worth a few watts too (but are a bit less convenient as need to be pumped before every ride).
