Thx Eric , just find this thread, what a gem!!!

I'm considering a P-series
Height 172 cm height
Between legs 76 cm
Torso 65 cm

What's tour opinion 48 or 51?

Thxxxx

hey, thanks for reaching out.

That's a hard/tricky one. Sight unseen I could just as easily say 54cm, but that's just me as I'm somewhat heterodox when it comes to reach and what it's for and why it's important. In other words, I'm sort of hinting that you're asking the wrong question or boxing yourself in to a bad answer with your question phrased the way it is. How do you feel about a pre-purchase bike fit?

Do you have any pictures of you on a bike? A current tri bike? We need some more data to suss this out, but it's doable.

That said, the P-Series comes with a *very* adjustable cockpit and a 51cm would absolutely work for you.

Make sense?

Eric

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Aerodynamic Retul Bike Fitting

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I'd definitely go for the bigger frames for stability
You've got plenty of room to go down or fit Ascalons, although the dimensional data from Aerocoach is inadequate so it's hard to work this out precisely.

Makes Sense, of course. From what i read in this thread i like your opinions.

O have a Slice 2017 , size 48, that's why i talked about 48 or 51.
For the P5 disc you would also recomend 51?

Do you have a video of you riding your bike on a trainer?

I’d need more information to make a hard recommendation.

All I can say is most people are on tri bikes that are too small.

E

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Hi Eric,

I’m considering a P-Series or P5 for Olympic and 70.3 distances. I had a Retul fit and received the following measurements:

Saddle Height: 758 mm
Stack: 553 mm
Reach: 423 mm
Arm Pad Width: 234 mm
Arm Pad Reach: 452 mm (BB horz to back of pad)
Arm Pad Stack: 671mm (BB vert to top or arm pad)

Can you recommend sizes for each bike? Let me know if any other information would be helpful.

Thanks!

JD

Hi JD, thanks for reaching out.

With a Pad Stack of 671mm and a Pad Reach of 452mm you are in the upper left quadrant of a 56cm P5d. Your coordinates barely hit on the back of the 58cm, but really you're a solid 56cm. Same for P-Series.

Make sense?

E

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Eric Reid AeroFit | Instagram Portfolio
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Hi Eric, cyclenutnz,

Thanks for your advice on my fit. Was able to obtain a P5 disc in 58 for a good price. Currently waiting for the pm with 165mm cranks and new saddle to arrive.

Looking forward to hopefully some good autumn weather to give it a spin. Otherwise I can get my position dialled in on the Taxc.

Thanks again for your great work for this forum!

Kind regards,

Pim

 Hi Eric,

First of all thank you very mich for this gear oppurtinity here.

I am from Germany and I am looking for my first TT bike.

I have never sat on such a bike and need once a brief assessment of what frame size would fit me quite well. I am looking for P2 or P3 Version, because I dont want to spend too much money on my first TT bike.

I am 180cm tall and have a inseam length of 90cm. So I have long legs.

I'm looking at different sellers for sizes 54 - 56.

On my Cervelo S3 I ride a 56 with 0mm offset seatpost and 90mm stem.

I have unfortunately no experience to the specifications of pad stack and reach.
I would be very happy about an answer

Great, glad it worked out! Keep us posted.

Eric

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Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

Hi, thanks for reaching out.

At your height I'd say at *least* a size 56cm. I'm assuming you're talking about the "new" P2 and P3 and not the "classic" frames which are longer and lower. When finding a tri bike, you're looking for the longest bike possible that's still low enough for your position. An ideal solution would have you on a frame that allows a 90mm stem slammed or at least no higher than the top of your behind-the-stem bento box. If the bike requires a lot of spacers under the stem, you should go to the next size up. While 56cm would be the most recommended size for you from most reputable fitters, I have had fit clients who are your height who ended up riding 58cm bikes. It all depends on your stack and reach coordinates and which bike best fits the configuration required to meet those points.

Make sense?

Eric

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Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

Many thanks.

Yes exactly, I mean the newer P2 and P3. Specifically, I have the 2018 and 2019 frames in mind because there is still availability from time to time.

Tomorrow I have the opportunity to test drive a P3 in 56. I will report here then.

Hi Eric,

just want to share the informations from the fitting with you. The fitter simulated a newer P3 in 56 with 70mm stem, all spacers possible and 20-30mm riser under the extensions. Saddle height ended up in 814mm, crank length 172,5mm.

I am not sure, if this model is the right one for me or if I have to look for a frameset with less reach and more stack.

Your position looks very comfortable.

Your cranks are too long.

Many thanks for your reply.
What would you recommend besides the shorter cranks? Less armpad stack and longer stem or sit further back?

I agree about shorter cranks... anything longer than 165mm shouldn't even be tested or tried for a triathlete on a time trial bike.

You allude to the fact that you have a short torso or long legs but much of the shortness of your torso is caused by how you effectively shorten your torso by the way you are sitting on your saddle. That's either the wrong saddle for you or your sitting on the right saddle wrongly. Your saddle is ~ +10mm in front of the BB yet you are sitting all the way back like you're riding a road bike. This shortens your reach in two ways... one the way I described above, the effective shortening of your torso, and two the fact that you've set your bike up to incentivize sitting back as far as possible because that's most comfortable and ignoring your aerobars altogether.

With your current position you are a bad match for a long and low bike and would be better suited for a Specialized Shiv or Felt IA. That said, if you saw me for a fit you'd be just fine on a 56cm P3 or P5d, and probably most optimal on a 58cm.

Eric

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Okay thank you very much. Sorry, I don't want to spam the whole thread here.


I understand it this way: P3 fits in 56 or 58. But then change position on the bike. Different from the pictures. Or a shorter, taller bike. Is that correct so? Thanks again.

You're not spamming, but you're welcome to private message me.

Yes, I think you understand it right.

Eric

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Interested in a PX

X 515 to the middle 470 to back
Y 595 no pad

Width of arm pads 240 center to center

What frame size? Looks like I can fit nearly all on their site SMH

XL would just come into range if you had 10deg tilt or more
You're right at the front of the M fit range - better to go with an L for stability

Is the geometry the same on the PX as the P3X you showed?

I’m 5 foot 8 with a 715 saddle height. Ride a 51 now (and probably should be on a 54) .

Large and XL sizes shocked me.

Hi thanks for reaching out.

You're a medium or large in the PX. Lower center of the large range, mid right of the medium range.

Eric

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The XL only comes into range *because* you'd have the pads all the way back AND *if* you max out the tilt effectively lowering the back edge of the pad.

I'd caveat that with a maybe because I'm only guessing that the drop from tilt is 20mm.

E

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Thx.

So when in this situation, can fit a medium and a large, what does one go with?