Eric
Can you give P5X size recommendation for my measurements:

Stack - 645
Reach to back of pad- 45
Saddle - 730

Thanks!!

with pad stack of 645 and a pad reach of 450 you could conceivably be a M, L, or XL in a P5x but I think you're a L and this is why.

Your fit coordinates seem a little on the narrow-tall size of the Mendoza line, IOW I would expect someone with that stack to be a bit longer or someone with that reach to be a little bit lower. I'm guessing your fit might evolve over time in a longer and lower direction, or at least you want to buy a bike that would fit you now but also allow for that possibility in the future.

With a M, you could get the stack height you need (barely) but wouldn't have much reach forward adjustability. With the XL, you're barely on the reach chart and would run the risk of not being to get much lower if it came to that.

So, long story short, you're a size L in a P5x. Bars turned up, mono-riser at 60mm, pad holder flipped backwards, pads at mounting hole # 1.

Eric

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I'm 6'7". I currently ride the P5-6 (61cm). I like it; it fits as well as any TT bike could for a tall person like me. But now, Cervelo is making the P5X in XL and the P5 disc in 58 (not 61). Unless I'm missing something, the 58 P5 disc will be way too small, and I'm skeptical that the P5X (XL) would have enough fit flexibility to fit. For example, I wonder how much seat post I would need, and that seems like a lot of sway in the exposed seat post to be stabilized by the seemingly small area that the seat post sits in. I'd be concerned that it would just break if I swayed too much side to side. ???

I'll try to remember to go home and get the X and Y measurements to help in answering this question. In the meantime, is any other tall person in this predicament? Solutions?

the seatpost will absolutely not break. Carbon fiber is very strong and there aren't any serious forces there to break anything.

If you give me your saddle height and pad stack and reach I can give you a solution.

I hear what you're saying about the 58cm P5d but with the P3x EX-10 mono-riser you can get pretty close to an XL P3x.

Let's see your fit coordinates and go from there.

Eric

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Hello Eric

I have an old Kestrel Talon SL that I use with time trial bars and have been fitted for triathlon.

Looking at P2 or P3. If I give my pad x and y will it translate given the seat tube angle on a talon road bike is 73/74 deg?

Will it help if I give a reference to the saddle location?

Sorry if this was covered previously.

Thanks

Hi Eric,

These are my coordinates:

Pad X: 505
Pad Y: 615

I'm interested in getting a new P5d. What would be the best size for me.

Thanks

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with a pad stack of 615 and a pad reach of 505 you are long and low.... congratulations! You are a 58cm P5d with the mono-riser at 4mm and the pads set in the +30 position. from there, you could go an additional 4mm lower and 12mm forward.

You could get a little longer however using the EX10 mono-riser from the P3x if you needed to, which would also give you native ability to tilt.

Eric

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Fit coordinates, or in other words Pad Stack and Pad Reach (or Pad Y and Pad X), are independent of bicycle geometry or seat tube angles. They are your contact points. The way I locate the saddle in space is to give a reference from the tip of the saddle to the center of the BB, with a + number being in front of the BB and a - number being behind the BB. Then, I give the tilt angle of the saddle and then you're good to go.

Do you have a reasonably good position now that you'd like to transfer over from your Talon to a new Cervelo?

Eric

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OK thanks.

Pad X: 415 (this seems short compared to others? is this due to the - 95 mm saddle reference below?)
Pad Y: 683

A VERY rough saddle reference has it - 95 mm. regarding angle do not have official measurement but it is essentially flat.

My fit is fairly comfortable on the Talon.

Thanks!

yes, you have a very upright position or what I could call a "bike shop fit". It's not necessarily *because* of your saddle setback, but, and depending on the saddle, it's a contributor.

For example, in a P3x you're barely on the charts... you have the reach of a Small but the stack of a Large or even an XL.

I know it's not the question you asked, but I would start again with a reputable fitter and do a pre-purchase fit before committing any money to a new bike. My first thought is that you should get the biggest bike that is also low enough, but I feel that once you get into a "proper" TT position you'll wish you had a smaller, lower bike if you went the larger size route.

Eric

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Great information. Thank you!!!

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Pad X - 473mm
Pad Y - 749mm

Thanks for you consideration

Like with a previous poster, your fit coordinates are a red flag for a very upright position for the given reach, your height notwithstanding. That said, your numbers are also a red flag because with a pad stack of 749mm you are off the charts for both the P5d and P5x, and reach is barely on the chart of the XL or 58.

If I were you, I'd be looking at the P5x (or P3x) or the P5d with the EX10 P3x mono-riser, because those options will give you the most reach for your tall frame.

I think I'd like to see a picture of you on your current bike with these fit coordinates, and also encourage you to go see a reputable fitter to help you get into a more comfortable and "orthodox" TT position. For example, if you maxed out the P5x, you'd get a Pad Stack of 725 with a Pad Reach of 510mm. You could conceivably get out to a Pad Reach of 545, but any additional reach from 510 would require the mono-riser to be lowered... ie. the mono-riser goes up and down on the 17 degree head tube axis, so up and back or down and forward.

Does what I say make sense?

Eric

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that's actually a reasonable position... are you sure about the stack height?

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I'll check it again. I did the measurements with my two un-interested boys. I subscribe assistance from Mrs. TriFloyd next time.

With the help of Mrs. TriFloyd, slight change.

Pad Y - 743mm
Pad X - 448mm

does that change anything?

I appreciate your time/consideration.

well, you're still very upright, but it does not change anything.

Can you post a pic of your setup?

Eric

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Hi Eric,

Reach x = 410 back of pad
Stack y = 620
Saddle = 725
Height = 173

Interested in P5d but not sure I'd fit.

Thanks John

With a reach of 410 and a stack of 620 you're in an upright position and would fit on the very top end of a 48cm P5d.

I'd like to see your position though, and see how it might evolve, because with just 3mm more reach, you'd fit a 51cm P5d. Does this make sense?

I'd almost recommend the 51cm sight unseen, but if you have a position pic it could help.

Eric

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Thanks Eric,

The only pic I have,

OK I could totally see you on a 51 instead of a 48.

If you posted a critique my fit thread people would probably move you forward and lower and this would put you square in the range of a 51.

You also might consider the EX-10 P3x mono-riser for your P5d which would give you tilt and additional reach and width benefits.

Eric

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Hi Eric

Looking at the P3X:

Pad Stack 625
Pad Reach 465
Pad Z - 200 (center to center of cups)

Thanks,
Chris

hi Chris,

with a Pad Stack of 625 and a Pad Reach of 465 you are a M or L in the P3x.

With the M, you'd only have an additional 15mm of reach to play with, but you could drop up to 60mm of stack. Conversely with the L, you'd have much more reach to play with but would only be able to get 30mm lower if need be.

I'd have to see your fit and estimate your fit progression before choosing one for you, but if you know your position is locked then you could do well with either one, probably the M which would be lighter.

You might know me though, and truth be told I'm making assumptions about your fit and wonder if you might be longer and lower after a session with me....

Do you have a pic?

Eric

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Thanks Eric. I'll find a pic and attach. This fit was on a 56cm P5. I always felt too stretched out. Seat nearly all the way forward, and more of my forearm on pads than elbows when comfortable.