Official FIT ASSISTANCE for Cervelo TT and Triathlon Bikes

Triathlon Forum
964

I have a feeling that you aren’t the best bike handler because your bike doesn’t fit you properly.

Ha, this is good for my ego. Thanks.

Kidding aside, curious as to what you would change vs my current bike setup. And in the context of this thread: would the P3x size M be a better fit? Apart from the great advice from Eric already.

It’s a bike, not the lunar lander… you can ride it. Plenty of perfectly sized perfectly fit athletes leave my studio who can’t even drink from a bottle while riding.

Also not sure that a size M in the PX series even fits you.

E

Hi Eric,

After our conversation I started tweaking my current bike setting. I have a feeling that I could increase pad reach by at least 80mms. Leading to pad stack 610, pad reach 500.

Now, my current bike doesnt allow for tilt and extensions arent long enough, so I can’t really try it out for real rides. But moving pads forward by that much and doing some test runs, I can see myself get real comfortable in that position if properly supported by tilted pads and extension.

Any insights as to PX size-wise given the new dimensions? I guess size L with riser almost slammed? Thanks again!

You can get a size M at 495mm reach. Why are you coming up 80mm?

Edit: I see you mean reach.

E

Sorry, not up. Stack unchanged but reach +80mm after your prior suggestions to get longer.

Edit: see your edit now. Thanks.

965

Pad X (pad stack) - 727mm
Pad Y (reach) - 469mm
Arm pad reach (BB) 431mm
Pad Z (pad width) - 234mm

I don’t have a tri bike (yet). Looking to purchase one for a 70.3 next year. I am actually looking at a used P3 that is a 56.

966

Pad X (pad stack) - 727mm
Pad Y (reach) - 469mm
Arm pad reach (BB) 431mm
Pad Z (pad width) - 234mm

I don’t have a tri bike (yet). Looking to purchase one for a 70.3 next year. I am actually looking at a used P3 that is a 56.

hi, thanks for reaching out.

With a Pad Stack of 727mm and Pad Reach of 429mm to back of pad, you would be a little off the charts with stack, 27mm too high, for a 58cm P5d. You’d be right in the left-center of the reach range though. For reference, the top of the range for a 56cm P5d is 685mm.

If coming down is not an option, you’d be in the left center of the range of a size XL in the PX series bike.

Eric

967

hi, thanks for reaching out.

With a Pad Stack of 727mm and Pad Reach of 469mm you would be a little off the charts with stack, 27mm too high, for a 58cm P5d. You’d be right in the center of the reach range though. For reference, the top of the range for a 56cm P5d is 685mm.

If coming down is not an option, you’d be in the top center of the range of a size XL in the PX series bike.

Eric

Thanks - I appreciate your time!

968

Does anyone know when the EX10 tilt kit will come back into stock ? I can’t find the whole thing anywhere.

969

On the P5d, the pursuit bar is inline with the top tube essentially.

Hey Eric basic question as i am looking at a 2020 P5 56cm. I can see clearly the arm pads rise up but does the base bar? Or is the base bar remain parallel with the top tube and can not be risen slightly?

970

On the P5d, the pursuit bar is inline with the top tube essentially.

Hey Eric basic question as i am looking at a 2020 P5 56cm. I can see clearly the arm pads rise up but does the base bar? Or is the base bar remain parallel with the top tube and can not be risen slightly?

You can flip the basebar up or down IIRC, but you can’t raise it more than that. The mono-post is how you raise and lower stack.

Eric

971

Hi Eric,

Thi is my first post after being a long team reader on ST. Have been active in tri (up to half distance) until a few years back, then life happened and now finally able to get back into the great sport.

I used to own an old 2nd hand tri bike, which I sold. Since then been riding on a road bike.

Now looking into getting properly set up (again) so planned a bike fit yesterday which led to the following numbers:

PadX: 484 mm
PadY: 651 mm
PadZ (C-C): 210mm
Saddle height: 824mm
Saddle setback (ISM PN 3.0): 28mm // 112 clamp-nose
Extension angle: 15 degrees
Crank arm length: 165 mm

Based on this, could you please advise wether a size 56/L or 58/XL for either a P5D or a P3x/Px series would be the best option?

Based on Cervelo’s geometry tool, it seems that both should work based on X/Y, but I would also like to be ‘future proof’. For example if I would like to upgrade to custom extensions such as Aerocoach Ascalon (which adds 35mm stack).

Another question, regarding crank length. I noticed that Cervelo bikes don’t have the length listed by default. However some research seems to show that 58/XL bike comes with 175mm cranks and 56/L comes with 172.5mm cranks. Given the shortage of parts, i think it’s somewhat realistic that I might not be able to find 165mm cranks on a short notice. How should I adjust my fit coordinates to work with these longrr cranks? I assume lowering the saddle so knee extension angle doesn’t change and then increading PadY to maintain hip angle, or do you have other thoughts on that?

Finally, I seem to notice that the P5D only comes with the EX11 monopost, which cannot get to the 15mm angle. Is this swappable for an EX10 and does an ex10 increase/decrease PadX/Y compared to ex11?

I have included a picture from the bikefit as well for reference.

Thank you very much in advance for your input!

Kind regards, Pim

972

You could get 155mm cranks in a few days if you wanted.

973

Hi Eric,

Thi is my first post after being a long team reader on ST. Have been active in tri (up to half distance) until a few years back, then life happened and now finally able to get back into the great sport.

I used to own an old 2nd hand tri bike, which I sold. Since then been riding on a road bike.

Now looking into getting properly set up (again) so planned a bike fit yesterday which led to the following numbers:

PadX: 484 mm
PadY: 651 mm
PadZ (C-C): 210mm
Saddle height: 824mm
Saddle setback (ISM PN 3.0): 28mm // 112 clamp-nose
Extension angle: 15 degrees
Crank arm length: 165 mm

Based on this, could you please advise wether a size 56/L or 58/XL for either a P5D or a P3x/Px series would be the best option?

Based on Cervelo’s geometry tool, it seems that both should work based on X/Y, but I would also like to be ‘future proof’. For example if I would like to upgrade to custom extensions such as Aerocoach Ascalon (which adds 35mm stack).

Another question, regarding crank length. I noticed that Cervelo bikes don’t have the length listed by default. However some research seems to show that 58/XL bike comes with 175mm cranks and 56/L comes with 172.5mm cranks. Given the shortage of parts, i think it’s somewhat realistic that I might not be able to find 165mm cranks on a short notice. How should I adjust my fit coordinates to work with these longrr cranks? I assume lowering the saddle so knee extension angle doesn’t change and then increading PadY to maintain hip angle, or do you have other thoughts on that?

Finally, I seem to notice that the P5D only comes with the EX11 monopost, which cannot get to the 15mm angle. Is this swappable for an EX10 and does an ex10 increase/decrease PadX/Y compared to ex11?

I have included a picture from the bikefit as well for reference.

Thank you very much in advance for your input!

Kind regards, Pim

Hi, thanks for reaching out.

With a Pad Stack of 651mm and a Pad Reach of 484mm you would be either a size L or size XL in the PX. With the size L, your limiter would be that you’d only have 20mm more reach to play with. On the XL, you could only get 30mm lower. I suspect from intuition and hearing some things that the size L would be a couple watts faster and would accommodate the stack height of custom extensions.

In the P5D, you’d be a 58cm for sure, despite fitting ever so slightly on the reach of a 56cm, unless you know you’ll never get longer (a rarity for people who work with me) in which case the 56cm would help accommodate the increased stack height of custom extensions.

As for cranks, the industry is hopelessly behind. Bikes are shipped, and have been shipped since the beginning of time, with cranks that are 10mm too long for TT applications IMO. Also IMO, next to the saddle the cranks are what tie the fit all together so I’d work hard to get a swap done so that you can ride your preferred crank length.

If you go shorter than 165mm, there are better cheaper options so that you can have your cranks and still have a power meter, for example Cobb cranks and Assioma power pedals.

Make sense?

Eric

974

Hi Eric,

Thank you very much for your reply.

Would you say there is a significant difference between being high on a L or low on a XL P3X from a ride-quality perspective?

Would I already get to a point where I might experience being too far ‘ahead’ of the front wheel in this fit?

975

Hi Eric,

Thank you very much for your reply.

Would you say there is a significant difference between being high on a L or low on a XL P3X from a ride-quality perspective?

Would I already get to a point where I might experience being too far ‘ahead’ of the front wheel in this fit?

There’s a difference, but I don’t think it’s significant. That sort of thing is very individual though. It’s not like the old days though of short bikes with long stems, we’re on long bikes with short stems now. Maxed out pads on a 56cm is absolutely a use case that the Cervelo engineers planned for.

Eric

976

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

977

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

978

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.

Screenshot 2021-10-21 100753.jpg

979

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?

980

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

981

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?

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

982

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

983

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