CJB91

I'm currently looking at a few Cervelo p2 bikes available, one is in size 56 and the other 58. My Cervelo r3 is a size 58. Would I be correct in going for the size 58 p2? I've read that with some frame manufacturers it is best to go down one size which would be the 56 for me, however other people have said that some manufacturers take positioning into account and you should just purchase the same size frame as the road bike.

Could anyone please advise?

Bah Humbug

I have a 56 S1 and a 56 P3. I also know people who did -1 sizing to their Cervelo tri bikes from their Cervelo road bikes. You need to find a good fitter (ideally a FIST fitter - look on Slowtwitch) to tell you what stack and reach you need. If they can't explain what stack and reach are, clearly and quickly, they have no idea what size you should be on. Even moreso than road bikes, tri bikes need to be the correct size and random bike shop employees can't tell you which is correct (though I can't imagine going up a size is ever correct). It depends on your proportions and flexibility.

StanSeven

Great response. I can't think of anything more to add.

Marvil15

I had a 2009 P2 and have a 2008 R3, older geometry, I rode a 58cm in both. I agree with the above post that a pro fit is the best way to go as it depends on a lot of factors whether you should size down or not. I was told if I was buying the P2 for time trials then I might be better off on a 56 to get more aggressive but since I was doing tri's and du's the 58cm would be better. With the 2 position seatpost on my P2 I was in the forward position which basically equated to 56cm virtual top tube while the rear position would equate to 58cm.