I am looking at buying a 56 P3. I currently ride a 56 P2SL. With these fit coordinates will the P3 work for me?
Bike: Cervelo P2SL
Seat Tube Angle: 79 deg
Top Tube Length : 56cm
Saddle: Adamo
Pedals: Look Keo
Crank Length : 172.5mm
Seat Height (A): 76.7cm (14cm back
Seat Set back (B): 1.5 cm
Nose of Saddle to Stem Handle Bar Clamp: 54cm
Seat Angle: .5 deg Nose down
Grip Height: 55.5 cm
Cockpit Length (C): 85cm
Base Bar Angle: 3.3deg
Arm rest to tip of Aero Bar (D): 37.2cm
Base Bar Width: 42cm
Drop from Saddle to Arm Rest (E): 14.4cm
Aero Bar Angle 3.3
Saddle Nose to Back of Arm rest (F) : 48cm
Stem Length 9cm
Arm Rest Width (G): 22cm
Stem Angle: 80 degree
chris
I’d say most likely.
I think most of the Cervelo’s have pretty similar geometry/measurements - the biggest difference being the head tube on the P3.
I know the top tube on my Dual is the same as the same size P3.
Side note: I ride a 56 dual, and am contemplating a 54 P3 - simple to allow myself to get lower. I forsee having a grand argument with Brent over this fact if/when I go shopping.
Simple question. How many mm of spacers, if any are under your stem on the P2SL? Whatever the answer is, you’ll need 15mm more of spacers on the P3 (carbon, right?..not the old aluminum P3?) in the same size to get the EXACT same position.
Seriously…it’s that simple.
As long as the total amount of spacers ABOVE the 15mm tall “volcano” headset cap and below the stem doesn’t exceed 40mm, you’re good to go.
If someone does have a few too many spacers on a 56 P2 would a better option be a 58 P3 instead? Would allow for far less spacers. You would then need to adjust the reach but the difference between a 56 and a 58 is not much.
Just curious.
If someone does have a few too many spacers on a 56 P2 would a better option be a 58 P3 instead? Would allow for far less spacers. You would then need to adjust the reach but the difference between a 56 and a 58 is not much.
Just curious.
Sure…as long as the stem doesn’t get too short. I prefer to go with the largest frame that will “fit”, since it tends to increase the front-center dimension and thus make for more stable handling with a forward position.
just make sure you don’t have that seat too high.
So if I currently ride my P2 with two spacers and no cone I could add the cone on the P3 and be in the same position? Could I also then measure my seat height and seat distace from the base bar and keep those to effectively ride the exact same setup as I ride now? Is it that simple?
chris
Took a look at my bike today (gone for last two days) and found my description/memory was off. I currently only have one “small” Cane Creek cone/spacer under my stem so placing the standard cone and maybe a spacer would work on the P3? My other question about the seat height and reach being the same is still out there?
chris
Took a look at my bike today (gone for last two days) and found my description/memory was off. I currently only have one “small” Cane Creek cone/spacer under my stem so placing the standard cone and maybe a spacer would work on the P3? My other question about the seat height and reach being the same is still out there?
chris
How many different people do you need to tell you what Tom A already told you?
Steve
Took a look at my bike today (gone for last two days) and found my description/memory was off. I currently only have one “small” Cane Creek cone/spacer under my stem so placing the standard cone and maybe a spacer would work on the P3? My other question about the seat height and reach being the same is still out there?
chris
Yes…it’s that simple. The difference between a P2SL and a P3 geometry-wise is just that the head tube is shorter on the P3. The position in space of the front wheel and the bottom of the headtube relative to the BB is identical between those 2 bikes. So, all you need to do is account for the 15mm shorter head tube. Voila! You don’t even need to change your stem. Like I said above, the 3T fork has a limit of 40mm of spacers (not including a headset cap of up to 15mm). As long as you’re under that, you’re good to go.
On the seat position, there’s plenty of adjustment range on either bike to get your seat in the same spot relative to the BB. Actually, that’s how I prefer to set it…measure to the top of the seat from the BB vertically, and then to the nose horizontally from the BB. It’s just like “stack and reach” for the saddle. You can use the nose to pads measurement as a secondary check that you got things right.
Tom, thanks for the patient and informative answer. That is exactly what I need to know. Much appreciated.
chris
I do believe there is 4mm difference in reach between the two bikes. But I guess not enough to worry about. Otherwise a 5mm shorter stem would do the trick.
I do believe there is 4mm difference in reach between the two bikes. But I guess not enough to worry about. Otherwise a 5mm shorter stem would do the trick.
That difference in reach is because the headtube is angled. Do the trig…15mm x cos 72.5 deg = 4.5 mm. But, once you put 15mm of spacers under the stem, it’s in the exact same spot fore and aft as with the P2SL. No need for a shorter stem.
Here are the dimensions that tell you that the only difference is the headtube length. Both bikes have a 72.5 deg head tube angle, a 60mm BB drop, and a 626mm front center. That means the fork and front wheel on both bikes is located and oriented exactly the same relative to the BB. Since they both use forks with the same geometry…well, I think you get the picture 
Thanks Tom. I think I finally get it. My problem is that I don’t want a P3 with a giant stack. I am just trying to figure out would a 58 or a 56 make more sense… Looks like a 56 would have a big stack and the 58 would need a pretty short stem. Might be as small as 80mm.
Thanks Tom. I think I finally get it. My problem is that I don’t want a P3 with a giant stack. I am just trying to figure out would a 58 or a 56 make more sense… Looks like a 56 would have a big stack and the 58 would need a pretty short stem. Might be as small as 80mm.
Stem length guidelines aren’t as applicable to TT/Tri bikes as they are with road bikes. This is because different basebar and pad configurations change the relative orientation of the pads to the steerer tube. For example, I was running a 100mm stem on my P2K with a Vision basebar and Profile T2+ bars and pads. When I switched to a Scott 100K bar (with pads mounted to the bar as opposed to behind the basebar clamp as with the Profiles) I had to go to a 50mm stem to put the pads in the same spot relative to the steerer. The stability is exactly the same since the distance from the steering axis to the contact point (the pads) is preserved.
So…what I’m trying to say is that just because you would need an 80mm stem, it doesn’t mean that the handling will be bad. It depends on your bars…Also, don’t forget that the 58 will have a slightly longer front-center dimension which adds stability.