At the risk of sounding completely stupid, I have a question. I have never owned a TT bike and today got the opportunity to get a p3 built with nice parts for a great price. As of now, I ride a Cervelo Soloist 61cm and me seat is most of the way forward. This p3 is a 56 and to get close to the same fit, we had to push the seat most of the way back as well as using a stem that was slightly longer. I know very tittle about bike fit, I should, but I don’t. I am especially in the dark about going onto a TT bike after using a road bike.
Is a 56 too small for me in a p3 or not? what sort of things do I need to look at when getting on a TT bike? it appears that the bike will fit me, although I will be in a much steeper aero position (thats the point though right?). The guy I am working with knows his stuff and we worked on taking measurements from my soloist and adjusting the p3 accordingly. what measurements do I need to focus on to figure out if this is the bike for me? obviously I need to ride it, this brings up yet another question, what ride characteristics do I need to look for when taking a steep TT bike out for a spin?
Whoa - 61cm Soloist to a 56 P3? One or the other does not fit you (or maybe neither do!).
That Soloist has a very tall head tube relative to the P3. To fit on that, I’d think you’d need a lot of spacers. Either that, or you ride the Soloist a lot higher than you “need” to.
And important fact here is whether the post on the Soloist is forward or in the rear road position. Same for the P3. Not much point riding a P3 most of the way back and on the rear position!
I am hesitant to attempt to answer your question(s) because of the sheer volume of information necessary to frame an intelligent response. i suspect I am not alone in this response.
There is a tremendous amount of writing on this topic in the technical section of this website, and I would suggest that you begin there, and use the forum as a resource for more specific questions once you have a better understanding of the baseline info available there.
One or the other probably don’t fit you, possiby even both…usually road and tri bike sizes are not more than one size apart for a given person…tri bikes often one size smaller…make sure you know what you’re doing…size matters…
okay, so just ignore the size specs first off, the 56cm might fit you (assuming the 61cm is just right) as often you can ride a smaller TT bike than a tri bike.
question is do you want to ride steep or shallow? If the seat on the P3 is moved all the way back AND the seatpost head is flipped to the rearward position, you’re in a really shallow position which may work for some people but if you’re going to ride all the way back there than you might just want to keep riding the road bike… Generally consensus is a TT bike should be set up at least relatively steep and although you don’t really know much about fit, the main reason you probably are getting the P3 is to get into more of a TT/aero position and riding steep and this position kind of go hand in hand.
I’d say get the P3 if:
-with the seat clamp flipped foward you can find a setup that works for you with the saddle in the front 2/3 or so of the saddle positions allowed by the saddle rails (just made this up in my head…)
-above assumes you’re sitting on the frontal portions of the saddle as if you’re scooting aaaalll the waaay back on the saddle again you’re riding shallow and what’s the point
-you can get an aero position with your body at least kinda sorta meeting the slowtwitch approved upper body fit (found on this site) of 90deg angle at the shoulder, back and upper arm, and 90deg bend at the elbow, upper arm and lower arm.
-you can do the above withoout having to go to a ridiculously long stem (say greater than 140cm or so, and even that sounds a bit long)
-you can set yourself up without a ton, say more than 10cm (the ST crowd will say 3cm) of spacers under the stem. The P3 headtube height is very low, not the best setup for everyone.
I get what you are saying, If I’m going to a slack position, whats the point in getting a p3, I agree. For what its worth, the stem we used was like a 120, maybe a 130, but you are right, that is going a bit long and as far as spacers, we only had the 1/4 inch top cap of the FSA headset.
I find that when I use a clip-on on the soloist, I am able to get an “OK” position, but not a “GREAT” position as I have trouble getting that 90 degrees with my elbows. I was able to get that on the p3, but I guess I still don’t think that the 90 degrees in the elbows is everything.
That link above may or may not show you the position I am working with on the soloist. but all things being equal, maybe I should hold out. I was just hoping I could make it work because I’m basically looking at a fully built p3 for like 2500.00 with a sweet build. but I am aware that if the bike dosen’t fit me, then then it will not be a good use of my $$$.
And important fact here is whether the post on the Soloist is forward or in the rear road position. Same for the P3. Not much point riding a P3 most of the way back and on the rear position!
The soloist does not come with the reversible seat post. However the P2SL seat post will fit a soloist I understand.
yeah, I don’t know. Good chance you can get that 56cm to fit. I ride a 54-55cm road bike (had a 56cm Cervelo but that was a bit big…) and a 53cm P3sl, probably a 51cm P3C.
You know one thing to consider is your hip angle. If you’re sitting pretty slack and your front end is ultra low, you’re going to have a pretty acute hip angle just meaning your hip is going to be coming waaaay up close to your chest and you’re not going to have all that much leverage if it comes up that high. Another benefit of the forward saddle position is that when you scoot the hips foward you open up the hip angle. Basically think your road bike position when you’re hands are on the hoods, powerful, stable, easy breathing and powerful. Now stick a pin in your foot, rotate forward from there and you get the same hip and upper body angles with your ass shoved foward and arms down and forward. That’s what a tri bike can do for you, a comfy AND powerful aero position versus just an aero position.
Here’s my $.02 since it sounds like we are close in frame sizing:
I am 6’4" with 36" inseam= taller and more leg than average.
My P3c is a 56cm, which most would consider too small. I have it set up in the forward post hole, because I wanted steep. I had to trade the seat post for a longer one to get my butt high enough. I have 2-3cm spacers because I am not THAT flexible, but still have something like 15cm drop. I have a 100cm model Carbon-X.
As for the Soloist, I found a good fit on a 58, standard post (did it have two holes to choose from?), 100cm or so stem. This was just a fit to see IF I even would fit well. I haven’t purchased yet purely for budget reasons.
In your case, going from a 61 Soloist “all the way forward” to a 56 P3 “all the way back” sounds like you are going awfully shallow, which puts you back in the Soloist position. So, here is my actual $.02: stay with the Soloist and keep your money. Or you could try a 58 P3, but go steeper, watch to make sure it will still give you enough drop.
I can’t believe no one has asked this, but what is your height, and what is your inseam (measured properly, not what trouser length do you wear)?
I know very tittle about bike fit, I should, but I don’t.
The guy I am working with knows his stuff
What makes you say that? The fact that he knows (or appears to know) more than you doesn’t necessarily mean that he knows his stuff. As the saying goes, in the land of the blind, the One-Eyed Man is King.
no way, got to agree with others, one of those is wayyyyy off! i ride a 56 soloist to train on, and a 54 P3 to race on. if my torso wasn’t relatively short, i’d be riding a 56cm on both. tri bike should be the same or darn close to road size
My previous tri bike was a 55 and the position seemed to be good, i picked up a p3c a while ago in a 51. Im 5’11 and thought that had to be too small of a bike but i think the fit is pretty solid, although im no expert.
And important fact here is whether the post on the Soloist is forward or in the rear road position. Same for the P3. Not much point riding a P3 most of the way back and on the rear position!
The soloist does not come with the reversible seat post. However the P2SL seat post will fit a soloist I understand.
recent carbon soloists have the single-position post, but i’m sure you could get the dual if you wanted. all others, incl. all alumin(i)um ones, and including mine, have dual-position posts.
I know I look that way, but I promise that while I AM stretched out, I am not as stretched out as that picture makes it look, Maybe tonight I can get good side shot and post it.
CarbonX = 100mm or 10cm. That is the stem length of the one piece handlebar.
The larger-than-normal for a 56cm P3c seatpost has 11" (27cm) exposed… measured frame to seat rail.
YMMV,
(Mo)Joe
