Very personal choice depending on your downhill abilities on each bike, the course profile, the difference in weight between your 2 bikes. My road bike is a climbers bike, 3kg lighter than my TT bike.
If there's a long and hard climb (like Hors catégorie in le Tour) followed by a descent, I go for my road bike
Tri races I did on my road bike (without clip-on aerobars) and was happy with my choice
- Nice 70.3 WC (1500m positive elevation over 90km)
- Alspman (4500m of elevation over 180km - no one rides a TT bike)
- Embrunman (4500m of elevation over 180km)
- I raced Andorra 70.3 last weekend (2000m positive elevation over 90km) and 90%+ of Age groupers were on road bikes, probably 50% of the pros. The male winner rode a TT bike.
Here are my strava files for the 70.3 Andorra race last weekend.
The course goes into a long flat tunnel for ~15km in total, hence the weird data, but I think total elevation on the bike was 2000m+. 2 serious climbs and 3 twisty descents.
https://www.strava.com/activities/5577404064
https://www.strava.com/activities/5577404007
and my race report, for what it's worth: https://mymsracesironman.home.blog/...3-ironman-july-2021/
It doesn't get easier, you just get slower
https://mymsracesironman.home.blog/
If there's a long and hard climb (like Hors catégorie in le Tour) followed by a descent, I go for my road bike
Tri races I did on my road bike (without clip-on aerobars) and was happy with my choice
- Nice 70.3 WC (1500m positive elevation over 90km)
- Alspman (4500m of elevation over 180km - no one rides a TT bike)
- Embrunman (4500m of elevation over 180km)
- I raced Andorra 70.3 last weekend (2000m positive elevation over 90km) and 90%+ of Age groupers were on road bikes, probably 50% of the pros. The male winner rode a TT bike.
Here are my strava files for the 70.3 Andorra race last weekend.
The course goes into a long flat tunnel for ~15km in total, hence the weird data, but I think total elevation on the bike was 2000m+. 2 serious climbs and 3 twisty descents.
https://www.strava.com/activities/5577404064
https://www.strava.com/activities/5577404007
and my race report, for what it's worth: https://mymsracesironman.home.blog/...3-ironman-july-2021/
It doesn't get easier, you just get slower
https://mymsracesironman.home.blog/