# Dilemma in frame size



## pReTeNd3r (Jul 8, 2012)

Hello all,

I finally pulled the trigger and ordered a red Dogma F8 frame. Now i am in a dilemma in deciding the size for my F8 as currently my Cervelo R5 is 56.

Should I choose the same size for F8 or should I go 1 size smaller which is 55..

Can all gurus give some advice?


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## MMsRepBike (Apr 1, 2014)

look at the geometry of the Cervelo, look for the Stack and Reach of your size.

then look at the F8 geometry chart and find the matching Stack and Reach.


You're going to notice quickly though that the R5 is an "endurance" geometry bike and the F8 is a typical "race" geometry so they don't match.

You'll want to keep the Reach the same or not change it much, the Stack is easier to change. 

Because they're quite different other factors are going to come into play. You will need to add quite a bit more spacers under the stem of the F8 than the R5 has. This will mean then that you're also going to need a longer stem to get the same overall reach in the end.


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## pReTeNd3r (Jul 8, 2012)

MMsRepBike said:


> look at the geometry of the Cervelo, look for the Stack and Reach of your size.
> 
> then look at the F8 geometry chart and find the matching Stack and Reach.
> 
> ...


LBS recommended 56 based on my bike fit data which i have given him. But my fitter recommended 55 as he find that the handlebar drop on the F8 might be too low.


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## MMsRepBike (Apr 1, 2014)

My quick glance says 55 is the biggest you should be on.
But I would need to know your stem length and angle now, the amount of spacers between the stem and headtube and the handlebar reach you have.

You're going to be running a spacer stack for sure though no matter what size.
Either that or an upturned stem...


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## pReTeNd3r (Jul 8, 2012)




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## MMsRepBike (Apr 1, 2014)

edit:

At first the F8 looked really bad for you to me, but in the larger sizes it looks better.

So I just ran the calculations. The 55 or below just will have too many spacers to be safe so it'll be a 56 you want. No pro fits possible here but whatever.

You'll stick with the same stem, same bars but will need 48mm of spacers under the stem. Generally Pinarellos will have about a 16mm bearing cap or so, so you'll need to add an additional 30mm spacers above that. 

This is of course given that your fitter didn't omit the bearing cap when measuring, I find that the vast majority do for some unknown reason.


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## mimason (Oct 7, 2006)

Wow 56 Cervelo to a 56 Doggie?

I have a ML Giant Adv SL which is a 57 with a 110 shimano -10 degree stem and went with a 54 Dogma F8 with a 120 -6 degree stem. Definitely needed to downsize and remove the F8 bearing spacer for a 4mm Ritchey to match a slammed Giant also with a low profile spacer. 

I could have also been a 55 but the 54 was the better choice. I size a 56 with Cervelos.

A 56 just sounds too big. I think the fitter is on target with the 55.


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## pReTeNd3r (Jul 8, 2012)

mimason said:


> Wow 56 Cervelo to a 56 Doggie?
> 
> I have a ML Giant Adv SL which is a 57 with a 110 shimano -10 degree stem and went with a 54 Dogma F8 with a 120 -6 degree stem. Definitely needed to downsize and remove the F8 bearing spacer for a 4mm Ritchey to match a slammed Giant also with a low profile spacer.
> 
> ...


Thank you for your suggestions. My height is 1.81m. I just do not want to regret getting a wrong size frame.


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## pReTeNd3r (Jul 8, 2012)

MMsRepBike said:


> edit:
> 
> At first the F8 looked really bad for you to me, but in the larger sizes it looks better.
> 
> ...


He did not omit the cap when measuring. So 56 will be a better choice?


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## MMsRepBike (Apr 1, 2014)

pReTeNd3r said:


> He did not omit the cap when measuring. So 56 will be a better choice?


56 is your only choice really.

If you go smaller, the spacer stack under your stem will exceed what Pinarello considers to be safe. I work for a Pinarello dealer, the biggest around for over 30 years, and I'm the bike fitting "expert" at the shop. My comments are based purely on actual numbers, the ones used to setup your bike. The comment above is just nonsense from someone that has no idea how to fit a bike. 

Plus, who wants a stack a spacers so big under their stem that they look like a super Fred? And on an F8? That's blasphemy. Most people don't care, but it's also quite unsafe and that's what's important here.

If you were like the commenter above and slammed your stem on the R5, like I do on my R5, then we'd be talking different frame sizes. But your limiting factor here is the spacer stack under the stem, that can only get so high safely.


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## pReTeNd3r (Jul 8, 2012)

MMsRepBike said:


> 56 is your only choice really.
> 
> If you go smaller, the spacer stack under your stem will exceed what Pinarello considers to be safe. I work for a Pinarello dealer, the biggest around for over 30 years, and I'm the bike fitting "expert" at the shop. My comments are based purely on actual numbers, the ones used to setup your bike. The comment above is just nonsense from someone that has no idea how to fit a bike.
> 
> ...


Hi, noted your Explanation. Then I'll get 56 instead.


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## mimason (Oct 7, 2006)

I don't claim to be a fitter and didn't look at the measurements from my phone but also never knew of a pinarello rider that didn't size down from most other brands. I'd guess that the R5 could be a 58 you ride. Good luck with that 56. You must be fairly laid back setup.


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## MMsRepBike (Apr 1, 2014)

If it makes you feel any better I ride a 54 R5 and in an F8 I'd be right in between the 51.5 and the 53, probably going with the 51.5. The OP though has a lot of spacers under his stem on an R5 already. I slam my stem on my R5, no spacers at all, just a bearing cap. That's the big difference here.


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## antihero77 (Jul 26, 2011)

I ride a 54 sworks and a 53.5 dogma and a 53.5 f8 all stems on all bikes slammed


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## shanehill (Dec 30, 2013)

I just recently switched from a 56cm Specialized Roubaix to a 55 Dogma. My fitter told me that since I ran the stem as low as it would go on the specialized, that he'd rather see me on a 55 with a longer stem than a 56.


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## Spcmnspff (Dec 23, 2014)

Ok late reply on a month old thread but here's what I've come to understand about pinarello sizing. Talking strictly about nominal sizing, pinarello uses the the "c-t" measurement defined as center of bb to the center of the junction of the top tube, seat stays, and seat tube. Where most other brands have their nominal size defined as center of bb to the very top of the seat tube. Some others I have found use something entirely different. In either case it's easy to see why we typically "downsize" when switching to a Pinarello frame. There's at least a 3cm delta when comparing these measurements.

Btw I don't ride a dogma. I ride a 2014 marvel I.e. the paris geometry. But in that frame I ride a 51.5 and it's the largest frame that could possible fit me. I'm 5'9" with a 30" inseam.


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