56cm vs 58cm bike - same model

Triathlon Forum
1

I am 6.1" and about 180.

I am currently riding a 58cm cervelo dual, would changing it to a 56cm P2C be an option? I haven’t been FIST fit but I am relatively comfortable on the 58cm bike. Will changing to a 56cm bike with the same frame geometry screw me up? I guess my question is can a person who is comfortable riding a 58 be comfortable riding a 56 with the same eficiency?

2

can anyone help me with this, i would love some help ASAP

Thanks
.

3

too many "it depends"s on this one and too important to wing it. go get fit.

4

As mentioned, nearly impossible to know from this information provided.

Conceptually though, the biggest difference to work around is the head tube length. The saddle to bar drop may be too much which means a bunch of spacers on the steerer. For a larger rider, this may mean a flexy front end. If used, the steerer may have been cut too much already.

You can use longer/shorter stems or move the aero bars back/forth to tune the effective top tube. If you get extended severely on a smaller frame, the weight balance is far too great on the front wheel and handling/safety could be a problem.

If you’re comfortable now, why go to a smaller size unless you need more saddle to bar drop? I suspect there’s a frame you’re interested in. Never compromise your fit for a “great deal” on a pimp bike.

5

Well, thats the great thing about stack and reach numbers. To achieve the exact same points in space with a 56cm frame, you’ll need almost exactly 2cm more spacers, and a 1cm longer stem. Then the 56cm should fit similarly to the 58cm.

If you already have over 1cm in spacers, an uprising stem, or a set of syntace aerobars on the 58, I don’t think the 56 is an option.

How those changes will effect handling, stability and so forth, I can’t tell you.

6

I am making a limited recommendation with the info, but pretty sure the 56 will work great.
Being 6’2" and doing fine on a 58cm!
Good luck,
Martin

7

I’m about your height (insert all the usual caveats here), rode a 58c Cervelo P3 for a while and then switched to a 56c a couple of years ago. No issues with the switch at all.

G.

8

I seem to recall that the Dual and P2C geometries are identical, so if you like the Dual 58 you’ll probably be best off with the P2C 58. P3C is a different story, different geometry.