As with all bikes we sell we measure the frames, preferably in each frame size, precisely using our measurement protocol to compare the actual dimensions to the size name designated by the company selling the bike.
In the case of the Cervelo P3C, these are our findings:
This is for a 56cm frame size (see box photo below as labeled):
Frame seat tube, total seat tube length as measured precisely from center of bottom bracket spindle to top of seat tube: 53.4 cm.
Effective top tube length measured as shown in below photo: 55cm. (note: this measurement is highly subjective- please look carefully at the photo of us measuring to determine if our technique is relevant to how you are sizing your bike).
As with many manufacturers, the dimensions of the bike are significantly different than the actual dimensions. This may be a very easy bike to get the wrong size in. The “56cm” actually has a 53.4 cm seat tube. See photos:
My bad. I should have asked “how do these measurements compare to other bikes in the cervelo line (P2K, P3) and to 56cm offerings from other manufacturers?”
If you check the geometry section of any of the Cervelo tri bikes, it states (and has since 1997):
NOTE 2: All our TT/triathlon bikes have a dropped toptube and shortened headtube to enable the rider to position the aerobars low enough for a proper aero position. This means that a frame measures smaller from the bottom bracket to the top of the seattube than it actually is and than the size would indicate. So the size is a virtual measurement, and all it means is that if you ride a 54cm road bike you’ll likely need a 54cm TT/triathlon bike as well. But since all manufacturers use different geometries, this doesn’t always pan out exactly either.
TD: “As with all bikes we sell we measure the frames, preferably in each frame size, precisely using our measurement protocol to compare the actual dimensions to the size name designated by the company selling the bike.”
nickc: “how do those dimensions compare to a Aluminum P3?”
Hey Gerard
Well the P3C is one fast looking bike! One question, why put the CSC sticker on it? I just never get that? It seems like the bike should cost less because you’re a rolling AD for CSC!
And one other thing I have noticed is that people seem to buy P3 that are to small? On most of the photos of people with P3’s they have a ton of spacers and an up swept stem?
“And one other thing I have noticed is that people seem to buy P3 that are to small? On most of the photos of people with P3’s they have a ton of spacers and an up swept stem?”
This isn’t always true…look at the length of those upturned stems…they’re really short. If that rider got a bigger P3 to get a taller headtube…the top tube would be too long for them. The P3 is not a good bike for folks who can’t ride fairly low in front. For those riders, the P2k would probably be a bit better since it has a slightly taller headtube.
“On most of the photos of people with P3’s they have a ton of spacers and an up swept stem?”
god bless you for noticing this.
it’s not that the bikes are too small, or the head tubes too short. it’s because the moron retailer sends the bike out the door with the seat clamp facing backwards, and as such the bike is now set up so as to be too long. so, in order to make the bike comfortable, he wrongly (remember, he’s a moron) concludes that the customer ought to be higher in front. hence, the spacers.
why do bike retailers not learn their lesson regarding bikes that are otherwise nice-fitting when positioned correctly? beats me. i keep wavering on this one, going back and forth between lazy and stupid.
“Yes. And this points out a number of things, one of which is that no one bike is good for everyone.”
i pointed that out… twice… in my bike reviews in triathlete magazine. and it got me fired… twice… it would be good if bike manufacturers did not get prickly when hearing this comment, and owned up to the fact that bikes are made for specific purposes, not just for specific markets.
imho, the person who really wants that cervelo post backward should be paying more attention to that p2.5 v madone thread, because that’s probably more the style of bike he should be considering buying.
And one other thing I have noticed is that people seem to buy P3 that are to small? On most of the photos of people with P3’s they have a ton of spacers and an up swept stem?
Dan…
I don’t usually make many comments here but I must. I like my P3SL very much, but I could use about 2cm more headtube. I have an 9cm drop in my pads to saddle height, and my back is flat. And I mean flat. I actually can’t believe I can ride it that way. And that is with 2.5cm of spacers and my stem flipped to give a 6deg. rise. And yes my length of top tube is spot on, all be it with a short stem. I would prefer a 52cm frame but the head tube is on 9cm. Way, way, way to short. Its time for Cervelo, one of the leading sales of TT and triathlon bikes to start making there bike for the masses. But wait! Why should they when we all buy them and just add a ton of spacers and short stems.
A question: why is the headtube ‘bulged’ out to the front? Is it more aero? structural reasons? other reasons?
Thanks,
curious george
For aerodynamics. The simple explanation: the widest point (side-to-side) of the headtube is set, it is the spot where the steerer goes through it. So if for a proper airfoil you need to start that airfoil a distance X in front of that widest point, that’s where the leading edge ends up. The complicated explanation is that on top of this, there is also a 3D effect going on, there are headset cups to integrate, the top and bottom of a shape see a different flow, the frame has to be structurally sound, etc.
“Yes. And this points out a number of things, one of which is that no one bike is good for everyone.”
i pointed that out… twice… in my bike reviews in triathlete magazine. and it got me fired… twice… it would be good if bike manufacturers did not get prickly when hearing this comment, and owned up to the fact that bikes are made for specific purposes, not just for specific markets.
imho, the person who really wants that cervelo post backward should be paying more attention to that p2.5 v madone thread, because that’s probably more the style of bike he should be considering buying.
Slowman…
We cant have comments like that being made that may infer that for as you say some people may be better off on a Trek than a Cervelo. You must be quite aware that Cervelo is a large, if not the largest sponsor of this site that you work for - did you not think of that? We are certain in our dogmatic minds that the Cervelo P3C is not only the best Tri bike of all time, it is also the best moutain bike and BMX bike with only a few small changes…and this is the best bike in any size for all creatures that are bi-pedal and upright (possibly some apes as well…no, certainly apes as well). We can not have your comments in the future seem to sway anyone from anything from Cervelo (or any other brand)…or you are fired.
