Wut? Why would there be any difference if you can achieve the same position? Most tri bikes are just TT bikes that have been through the accessories aisle at Walmart.

Is that a trick question?

that really needs a like button x10!!

Perhaps it was a typo or perhaps they are talking about the saddle restrictions that go with a legal UCI TT bike setup vs a triathlon bike

16 month baby/job/puppy/lack of sleep equals lots of typos.. Sorry folks. Road bike and tri bike

usually a few percentage points (3-6%). Also depends on the rider and how much they ride on TT bike i.e. more time on TT bike you might see less of a difference. Here's a thread I found discussing this in the past if you're interested in reading some older posts:

http://forum.slowtwitch.com/...to_TT_bike_P4236415/

Regardless, you'll go faster outside due to the aerodynamics on the TT bike.

me= zero
why.........most aero position is not a complete pretzel and road and tt set ups are very similar in saddle and relative body position

I train on my Tri bike only. I started riding a road bike on Sundays and I feel like I have no power at all. I am still adjusting fit and I have no power meter on my road bike but the average speed is way lower. The road bike is a lot more comfortable though.

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http://www.sfuelsgolonger.com

Mine is the opposite. Was on road for pst few months and have 70.3 to start the season in Texas in a few weeks so switched to tt. Power dropped aaaaa tttooonnnnnn. Was almost 30 watts lower on a workout I did on road bike last week. Awesome..

Well that makes more sense. Never bothered to look too deeply into power on my road bike, but from what I can gather it's about the same. I have a new position now so I'll need to see if I've lost any power as a result.

I'm about 10% down on the tt bike. I don't train on it though as it's not fun at all to ride.

about 10 percent down for me as well. I primarily train on my road bike (ftp around 250-260). When I ride my TT bike, similar efforts are around 20-25 watts lower.

I think its a combination of things. Not riding TT position enough, lungs are a bit more restricted, and a different "pedal stroke".

I'm actually the opposite from most people posting - I see a 10-15 watt gain in the TT position. My quads are stronger than my hams/glutes from years of ice hockey/skiing, so being more over the bottom bracket and engaging my quads more helps me.

I lose 15-25 watts in the TT position but it's OK BC I can go the same speed on 50+ watts less.

This thread makes me feel so much better about my power inadequacy on my TT bike compared to my road bike.

I go faster on it, but it sucks on the trainer.

Thinking of which, I suppose I should have two FTs - one for the TT, one for the road?

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Swim. Overbike. Walk.

Yep my FTP is 257. Was doing 105-120 percent effort workout and was legit having hard time at 230 watts. Just need to retest I guess on tri bike so I don't blow my "load". I was excited as I did increase my FTP over the last two months but all that work has been on roadie. Also thanks for enclosing the link on thread discussing this as well.

I had an FTP of 250 on my road bike, then I took 6 weeks off from training at the end of the season, bought a tri bike and got 210 in an FTP test on the new setup.

That was October and I've climbed back to 240 on the tri bike since then but I haven't tested again on the road bike. For me it's a mix of the new bike and the time off from training but I've definitely lost power. I'm in Canada so this is all indoors right now, I'm hoping that by June I'll back in the 250 range but a lot faster due to being so much more aero.

Are you using the same power meter brand / model on both bike?

I use the same Powertap Hub on both bikes. I did switch trainers though. Last season it was a Kurt Kinetic Road Machine, now I'm riding on a Tacx Ironman. That shouldn't make a difference but it's possible.

I am using a quarq on my road bike and PowerTap on my TT

in the tt bars i lose about 10% from road at FTP. Standing and pulling on bars gives a lot of watts.