Cervelo p1 sizing help

Triathlon Forum
1

Hello all,

I’m interested in buying a P1 but I’m trying to make sure I get the right size. I suspect it’s either the 58 or the 61

I did a fit calculation at competitive cyclist and here are the measurements and the recommendations.

Measurements

Inseam: 83.5
Trunk: 67
Forearm: 38.25
Arm: 73
Thigh: 68
Lower Leg: 59
Sternal Notch: 150
Total Body Height: 183

The Aero Fit

Top Tube Range: 59.8 - 61.8
Stem Length Range: 8.0 - 10.0
Saddle-Bottom Bracket Position: 75.2
Saddle-Pedal Position: 92.4
Saddle-Ground Position: 100.2
Cranklength: 177.5
Aero Bar Size: L
Saddle-Aero Bar Pad Drop Minimal: 5.7
Saddle-Aero Bar Pad Drop Moderate: 11.0
Saddle-Aero Bar Pad Drop Intense: 13.2
Saddle-Aero Bar Pad Drop Maximal: 17.0
Pad-Ground Position Minimal: 94.5
Pad-Ground Position Moderate: 89.2
Pad-Ground Position Intense: 87.0
Pad-Ground Position Maximal: 83.2

The road bike I own now is a 58 but my fitter seemed to think it might be a little small. He said it was more the size of a 56 or so.

Looking at the rec’s it says the most important measurement is the top tube length. This rec 598 to 618mm.

If I look at the geometry of the P1 I get:

For forward seat position:

58 Top Tube = 560
61 Top Tube = 574

For Back seat position"

58 Top Tube = 589
61 Top Tube = 604

So the two ranges are 560-589 and 574-604

The recommendation states 598 - 618

Does this point to the 61 since the high end of the 58 doesn’t even reach the low end of my recommended top tube range?

Thanks for any help…

Jason

2

hmmmm, if the bike your are riding now is a “58” that measures like a 56, then I would think that a 61 p2 would be too big. I have a 61cm soloist, fits perfectly, got a p2c, went down to a 58 and it fits perfectly.

YOu should go to your shop and get fit before buying, I would bet that you might want a 58, maybe a 56. unless you read something wront.

FTR, my soloist has like a 595 TT and I rid my p2 down at 56x for the top tube.

3

I guess I’m going to go to All Three tomorrow and see what they have to say but I’d love to hear more comments from here…

thanks

Jason

4

i ride a 63 road bike and a 58 p3alum. i ride quite steep (greater than 18cm drop)

i could have gone with a 56 p3, but the seat post would have been way too long/high. now i just run a negative 40 degree stem on the p3.

if you want to take my opinion, go with the smaller frame. you will be able to ride steeper on it.

5

Hey,

I measure 1m90 and inseam is 94 and I am riding a 61 P1. For me it’s perfect.
I think you will be better of with size 58 or even 56…

Kr,
Sam

6

I was working is a shop last year, I decided I wanted a p2c, I built up the 61cm because that was the roadbike size I was riding. That bike was freakin enormous, there was headtube and TT for days on that thing, I rode it for about 4 minutes and new I needed to go down to a 58. If you are riding a 61 in that bike you are very tall.