I still don't quite get it. Are you suggesting me to lower my handlebar (removing one of those spacers) on my current bike? Do I need to push the aero bar forward? I am aiming for a conventional non-disc P2/P3/P5 models. Having that said, between 48cm and 650c, will the latter be more suitable based on my physical stats?

I'm saying if you remove a few spacers from under your stem, push your pads forward to 385mm to back or pad, and find the right saddle, you might unlock some power/comfort/aerodynamics synergy.

I'm agnostic on 650cc bikes as far as comfort and handling go, but wouldn't recommend you one just because of your height. I think a 48cm P5d will be great for you.

Wait, are you saying you *don't* want disc brakes?

A 48cm P2/P3 would also work.

Make sense?

Eric

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Eric:

I run a Trek SC in side large with a reach at 540mm and a 655 stack. This puts me off the charts in reach. The reality is my SC pads are about 40-50mm up from my elbow (olecranon process) so i could theoretically fit on either the L or XL. If anything I'm set up a tiny bit over reaching in the tunnel chasing CDA numbers (.217) and would look to try to shorten the reach and play with stack a tiny bit to increase power and comfort for the full distance. (Pic attached)

Any reason to choose one over the other? I also run a 15 degree mantis tilt.

Zev

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hi Zev,

I'm a big proponent of having your actual elbows on the pads, so this will buy you 40mm of reach.

With a Pad Stack of 655 and a Pad Reach of 500 you're just *barely* in the range of a size L PX but fit more squarely in a size XL.

With the L, you'd be maxed out on reach and have no room to grow so to speak, but you could get a lot lower. With the XL you'd have an additional 30mm of reach to play with and could still get 30mm lower.

I'm leaning toward the XL, unless you show me a pic of you proving that a maxed out size L is the perfect reach for you and also that the picture shows you need to get more than 30mm lower.

Eric

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That makes more sense now. Just to be clear, you're suggesting making the distance of "Saddle tip to pad edge" from my current 335mm to 385mm?
Looking for a 'right saddle' is a bit unclear, is the current one NOT optimal enough?

I'm saying you should rotate your pelvis forward some, which for most fit clients means finding them the right saddle that will allow them to do this. If you did that, your body would be "longer" and you'd meed the pad minimum of 385mm without "reaching". Being somewhat lower also facilitates this pelvic rotation as gravity assists. You could also slide your saddle forward a touch.

What saddle are you sitting on now?

If you want, we can discuss this on the phone if you PM me.

Eric

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Maybe I dont get the idea of 'rotating pelvis forward'. I tried taking off a spacer under my stem and push the rest bar forward slightly and it's still ok. I am on a ISM PN1.1 btw

Looking for a new bike and went to get fit on a fit bike before making a purchase. The fitter has been doing bike fits for a long time on a fit bike which is what I wanted. Fitter was so interested to sell me a bikes he carried, and the bikes I said I was considering he said would not be good choices. The bikes I have been considering are cervelo(mainly p3) and speed concept. I don't necessarily need new and would consider used as well.

frame stack: 541mm
frame reach: 400mm
inseam:850mm

Any insights you care to share would be appreciated of which bike might be a good option.

I want to answer your question at the end but first: did he say why they would be bad choices? Huge huge *huge* red flag alert. The Speed Concept is one of the most adjustable bikes ever and the P3 can work for anyone with the right cockpit configuration, and with the right choices is as fast as a SC or P5-6. What does he sell?

Did he happen to give you pad stack and pad reach? I can tell you your exact Cervelo P3, P3x, P5d, etc. if you have those numbers.

The numbers you gave me are most similar to a 54cm or 56cm Cervelo P3. I'm already assuming you're not as rotated forward as I'd like, making you a touch more orthodox or longer and lower as it were. IOW, you've got the frame stack number of a 56cm P3 but the frame reach of a 51cm P3.

If you're *not* upright, and are in fact "narrow/tall" ie. long legs, you could still of course ride a P3 just fine, but it might open up some narrow/tall bike options that would have been previously disqualified.

Can you post a pic of yourself? How tall are you? Budget?

Make sense?

Eric

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Hi Eric,

I´m looking for a new bike and I really like the P3X/PX but I´m not sure about choosing size S or M.

I´m 173cm and I have 72cm of saddle height from BB.

I don´t have fitting numbers but I have ridden a Felt DA size 54 in the past. My Felt DA had 497mm of stack and 416mm of reach. For your reference the pictures below show my position on the Felt DA size 54. As you can see there wasn't much seatpost out of the frame. I would not like that to happen in Cervelo P3X/PX. Any suggestions ?

Thanks,

With a Pad Stack of 497mm you are below the minimum of a size Small P3x, which bottoms out at 540mm or so.

With a P5d you'd also bottom out at 540mm. Are you sure about your measurements?

Eric

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Hi Eric,

Thanks for your answer.

I meant that the Felt DA size 54 had a frame stack of 497mm and a frame reach of 416mm. I was not meaning pad stack...

any chance you could measure your bike from the floor to the pads, and then subtract the distance from the floor to the center of the BB?

Based on your reach you'd be at the very back end of a size M P3x so you'd probably be better off on a size S. We can confirm when you get me a final number for stack.

Eric

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Thanks Eric,

I sold that bike some years ago and I have no chance to measure pad stack, sorry. But looking at the pictures, based on the Felt DA frame stack of 497mm, I calculate about 80mm above the frame, which would be a pad stack of ~577mm

Hi

Appreciate any input.

So I got a bike fit yesterday and feel I may be a mutant.

Stack. 680
Reach 453
Pad center to center 260

Thanks for the help

JW

Why do you think you're a mutant? Before I answer the question... I just wanted to hear your take first.

Eric

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Hi

Thanks

Clearly not the expert here but don't seem to be in the middle of any range. Worry about adjustments down the road.

JW

Well with a Pad Stack of 680 and a Pad Reach of 453, you're in the upper left quadrant of a 58cm P5d or size XL P3x, or upper center of the range of a size L P3x.

Why worry about whether you're a mutant or not? If your fit is dialed, your numbers are what they are. If your fit is not dialed, you need two things:

One, you need to have a discussion with your fitter whom you just saw as to why you are not more orthodox... why are you so upright and slack if you're an otherwise healthy human being? Did you try all the saddles? Did you try all the crank lengths? Are you sitting right on the right saddle? Are you making the bike work for you and not the other way around? Did you drive the fit or did the fitter drive the fit?

Two, you need to select a bike that will allow your fit to progress or evolve, forward and down, rotating around the BB. The 58cm P5d and the L or XL P3x will all allow that. Very easily in fact. The mono-riser is a 10 second adjustment. The EX10 mono-riser with tilt is even better, adding and additional 15 seconds to the adjustment process.

What I'm saying in other words, is that there's no way you'll need adjustability in the *other* direction, ie. back and up. So, from where you are, 680/453 and upper left, you have nowhere to go but down so to speak, lower center right, and the bikes I listed will accommodate that fit evolution.

Make sense?

Eric

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hey

Thanks so much. This is incredibly helpful.

JW

Hi,

I am considering to buy a P3X but not quite sure about the size. Did GURU fit to identify the best frame and ended up with quite interesting results - size 54 for most brands except Cervelo where recommendation was size 51 for P3.

What size would you recommend if I go for a P3x based on the following:
Pad reach: 398
Pad stack: 640
Pad center to center: 190
Saddle height 745
Height 175cm

Thank you

With a Pad Stack of 640 and a Pad Reach of only 398 you are somewhat unorthodox, in other words high and "slack", or to the upper left quadrant of the fit range of a size S of the P3x, or just *barely* touching the left edge of the size M fit range.

Can you tell me more about your fit process? Sight unseen, your numbers indicate you're either a) a slightly strangely shaped human being, or b) your fit is slightly less than optimal, and with further postural coaching, perhaps a different saddle, etc. you'll move more lower and right in the fit range quadrant. I'm going to go with b) if only because it's the simplest scenario. If it's a), or it's b) but this is your final position, then that's fine too.

That said, and it is b), then the size S will allow for some room for your fit to evolve, perhaps 60mm forward if you eventually go ~ 30mm down.

However, if you evolve *too* much, the size M would be a better choice (with the caveat that first of all I'd have to see pictures and know for sure that you're headed that way and second a size M would require an immediate re-fit to get you into a more orthodox position). What I don't want to happen is that I recommend you a size S and one day you figure out an A+ time trial position and then suddenly the size S bike is not long enough. You'd be very annoyed with me!

Make sense? Size S P3x is the size for you unless you can show me otherwise, like you're a lot taller than I think you are or that some quick postural and saddle coaching would have an immediate and tangible effect.

Eric

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Hi Eric,

Thank you for quick reply! Have a look at the picture to back up the numbers. I forgot to mention that the bike is intended to be used by a female, hence different proportions unless we did the fit wrong.

regards
Alex

OK, based on what I'm seeing here I see room for "growth" but not so much that you'll go off the front of a size S and into a M. Hmmm.... unless perhaps you came to see me for a fit.

How tall are you? What are your goals?

Eric

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She is 175cm tall and I tend to agree that there is a room for growth. So, you suggest to go for a S?

Hi Eric,

Saddle choice is very personal, but which saddles do you normally recommend to get the best results ?

Thanks,