Pinarello Dogma Frame Size?

[vgb]

Hi Guys,

 

Some help please - how do i tell the frame size of a Pinerallo Dogma F8?  

 

There are no size markings on the frame itself. the serial number under the bb is : 6DB5300220099

 

Does this means it is a 53cm?

 

thanks.

 

[Owen]

Yes you are correct. It’s a 53. The Pinarello has a long top tube. Rather measure the top tube of the frame, to get a better idea if it’s the correct size for you.

[DieselnDust]

Yes you are correct. It’s a 53. The Pinarello has a long top tube. Rather measure the top tube of the frame, to get a better idea if it’s the correct size for you.

 

The top tube isn't unusually long for the class of bike that the F8 falls into. The overall reach (saddle cradle set back+ saddle set back+ reach) is long due to the 25mm set back saddle cradle.

What is quite agressive is the Stack measurement. Ignore the head tube length. With these aero bikes the fork lengths are typically quite long so the stack is important to compare across sizes.

[Jakkals.]

The top tube isn't unusually long for the class of bike that the F8 falls into. The overall reach (saddle cradle set back+ saddle set back+ reach) is long due to the 25mm set back saddle cradle.

What is quite agressive is the Stack measurement. Ignore the head tube length. With these aero bikes the fork lengths are typically quite long so the stack is important to compare across sizes.

unfortunately that is the incorrect. How will this individual correct his saddle to bars without altering the geometry of his setup, for the intended purpose of this frame.

[DieselnDust]

can you explain what is wrong in what i posted?

[TNT1]

The top tube isn't unusually long for the class of bike that the F8 falls into. The overall reach (saddle cradle set back+ saddle set back+ reach) is long due to the 25mm set back saddle cradle.

What is quite agressive is the Stack measurement. Ignore the head tube length. With these aero bikes the fork lengths are typically quite long so the stack is important to compare across sizes.

As a result, the headtube on aero bikes is short creating a lower frontal profile and having less resistance to overcome. As a general rule the headtube on a medium sized aero bike will be under 140mm, opposed to an endurance bike which will be over 160mm.

 

https://www.bikeexchange.com.au/blog/aero-vs-endurance-vs-lightweight

 

Which seems the opposite of what you're saying. I'll find reference to forks now. (Although preliminary reading suggests they are the same measurements across the board - although of course rake differs across forks)

 

Stack is the vertical distance from the centre of the bottom bracket to the mid point at the head tube.

 

https://www.cyclingweekly.com/group-tests/road-bike-geometry-explained-407599

 

Which suggests to me that it wouldn't change no matter what you do to the fork, but rather changes on the angle and length of the head tube and top tube.

Edited May 18, 2020 by TNT1

[DieselnDust]

https://www.bikeexchange.com.au/blog/aero-vs-endurance-vs-lightweight

 

Which seems the opposite of what you're saying. I'll find reference to forks now. (Although preliminary reading suggests they are the same measurements across the board - although of course rake differs across forks)

 

https://www.cyclingweekly.com/group-tests/road-bike-geometry-explained-407599

 

Which suggests to me that it wouldn't change no matter what you do to the fork, but rather changes on the angle and length of the head tube and top tube.

 

 

 

I'm saying broadly the same thing as the article.

 

the F8 is an aero race bike. It's got a longish top tube with a low stack. Per size it falls into a similar dimensional template with other bikes of the same class. Its not terribly different in the way that an Endurance bike is different to an aero bike.

What a lot of riders don't consider when just reviewing the reach measurement is that the seat tube angle adds to the saddle set back and then the frames often come with a proprietary seat post which typically has a 15-35mm set back. This lengthens the overall reach of riders reach to the bars.

Head tube angle and the riders equired stack will also alter that reach,

I say don;t look into the head tube length too much because some bikes are designed to run 32mm tyres and therefore the fork length will be longer like 375mm vs a bike designed around 25C tyres and the fork will be 368mm. but the stack of the two bikes will be the same. fork elngth and Head tube work together. With older bikes where 23c or 25C tyres and rim brakes made it easier because the fork length was pretty similar typically around 367mm to 370mm. Now with disc brakes and bigger tyres the rage as well as designers wanting to keep the down tube as close to the front tyre as possible for aero gains, means that the how the fork length is now determined by where its possible to fit that lower crown race and its position can vary by as much as 10mm on different bikes. 

[Jakkals.]

can you explain what is wrong in what i posted?

From your last post I can see that you do know a thing or 3

 

What I was trying to get at is, for this said bike, you cannot go and fix an overly long TT(which you wanted to ignore) with 1. zero setback seatpost(which will now make the seat tube angle >75degrees. now you cannot get your balance over your pedals correct and will loose pedalling power. 2. putting a shorter stem to make the reach to handlebars shorter will make handling too sharp.

 

You cannot exclude ETT length from your criteria.

[DieselnDust]

From your last post I can see that you do know a thing or 3

 

What I was trying to get at is, for this said bike, you cannot go and fix an overly long TT(which you wanted to ignore) with 1. zero setback seatpost(which will now make the seat tube angle >75degrees. now you cannot get your balance over your pedals correct and will loose pedalling power. 2. putting a shorter stem to make the reach to handlebars shorter will make handling too sharp.

 

You cannot exclude ETT length from your criteria.

 

 

Yes you are 100% correct, TT length cannot and should not be ignored. I must however by compared with the seat tube angle and the saddle post set back of the post that is shipped with the bike. Today for many bikes and the Dogma F8 included, the ssaddle post is a proprietary item. The set back of the cradle adds to the ETT. I would almost say that the this is more important than REACH because it informs the true position th erider is able to achieve on the bike. I played around with a few frame options to determine which size would suit me best  and discovered that a lot of the time there is very little different between small vs medium or 51v53. The bigger jump comes at 53 to 55/56cm or M to ML size range.

Personally I like to set up my cleats a little further back on the sole so I want a steeper seat tube or a 73 degree seat tube with a 0 degree set back seat post cradle.

 

within a limited range one can compensate for fit with different set back seat posts but then the frame must be able to accommodate a post other than the one it is shipped with or the riders physiology must accommodate that i.e. shorter legs longer torso. It with this knowledge that I can get 

Time Scylon small with TT 54cm (73 degree SA)

Cannondale Super 6 with TT 52cm (74.5degree SA)

Basso Diamante 51cm with TT 525cm (75degree SA)

Cannondale 2020 Super6Evo MkIII 54cm w  54.5cmTT (73.8degree SA) 

 

all to fit me and work in the same manner. They all fit the same but have their own distinct feel of course. Body is in the same position. 

The TIME requires the least amount of headset spacers thanks to it taller stack and a 11cm stem and a zero degree set back post.

The Super6 uses a 25mm set back seat post also with 11cm stem. Same position on both bikes.

If I were to size up on both bikes I'd only need a shorter stem on the Stem down to 10cm.

same with the cannondale.

 

The thing that makes this positioning possible and workable is understanding the ETT and the angles at the back of the bike that the geometry charts don't draw your attention to.

Edited May 18, 2020 by DieselnDust

[Jakkals.]

Well said. Many things to take into consideration.