colnago master x light sizing

[djdj]

Originally Posted by colker

Colnagos are designed different. They don´t follow the usual 73 degr head angle from every other road bike. That´s why sizing them should not be done by taking one measure from xbrand and picking a Colnago from there. It won´t matter if you have the top tube dialed by milimeters when the bike feels sluggish because the front center is too long, the front wheel and your weight balance are not not where they need to be. Stems are there to adjust the fit when the top tube is short by 0.5 cm. No big deal.
That´s how so many people end up buying three diff. size colnago frames till they get the right one. They transfer their measurements and expect a Colnago to work the same. It won´t. That´s why Colnagos are called "slow"... because people are riding frames that are too big for them. Measure them c-c and get a 1cm smaller frame. That´s the smart advice. It works.

To clarify, didn't you say above that you never rode a Colnago?

[colker]

Originally Posted by djdj

To clarify, didn't you say above that you never rode a Colnago?

A lot of friends ride Colnagos and have many of them, from masterlight to C40, c50, c59. HOw about you? Tell us your experience w/ fitting Colnagos. I am always curious about those bikes.

[wallymann]

Originally Posted by colker

Colnagos are designed different.

not true.

Originally Posted by colker

A lot of friends ride Colnagos and have many of them, from masterlight to C40, c50, c59. HOw about you? Tell us your experience w/ fitting Colnagos. I am always curious about those bikes.

i have and actively ride a master, C40, C50, and ExPower...along with bottecchia, gazelle, trek, ciocc, merckx, atala, somec, dean, etc.

pick a colnago size based on the STA and TT combo that allow one to get into one's desired position (saddle height/setback + handlebar reach/drop) using one's desired stem length.

it is literally that simple. (as long as one doesnt have really unusual position needs). if one overthinks it, one risks "buying three diff. size colnago frames till they get the right one".

colnagos ride fantastically, there's no black magic in off-the-peg colnago geometry...it's all pretty common-sense stuff.

[Dave]

Originally Posted by colker

Colnagos are designed different. They don´t follow the usual 73 degr head angle from every other road bike. That´s why sizing them should not be done by taking one measure from xbrand and picking a Colnago from there. It won´t matter if you have the top tube dialed by milimeters when the bike feels sluggish because the front center is too long, the front wheel and your weight balance are not not where they need to be. Stems are there to adjust the fit when the top tube is short by 0.5 cm. No big deal.
That´s how so many people end up buying three diff. size colnago frames till they get the right one. They transfer their measurements and expect a Colnago to work the same. It won´t. That´s why Colnagos are called "slow"... because people are riding frames that are too big for them. Measure them c-c and get a 1cm smaller frame. That´s the smart advice. It works.

I can't agree. I've owned 4 Colnagos now. 19 years ago, I bought my first C-40 and bought the same size as a previous Tommasini Sintesi, which was my last bike with a threaded steering tube. I used no spacers under the stem of the Colnago and a 110mm threadless stem with only a small rise to it.

You should select a Colnago so the reach and stack are the same as any other brand of bike that fits you well. The weight balance and steering geometry will be what they will be. If you don't like how the bike handles, then sell it and buy something with different geometry.

I've owned one Colnago and one LOOK frame at the same time. I used the same stem length on both and had no problem switching back and forth between the two. The front-center was 13mm longer on the Colnago. There was no need to buy a different size of Colnago. Just recently I sold that 16 year old LOOK frame and bought another Colnago, so now I have two.

Picking the right size is a lot easier these days, with most brands listing the stack and reach on their geometry charts. Unfortunately, Colnago doesn't list reach and stack for their classic frames. The 52cm Master is nearly identical to my current C-RS sloping TT frame. The head tube length of the Master, with the headset, matches. The TT length is only 3mm shorter, the STA is the same and the front center only differs by 1mm.

https://www.colnago.com/wp-content/u...RADITIONAL.pdf

[colker]

Originally Posted by Dave

I can't agree. I've owned 4 Colnagos now. 19 years ago, I bought my first C-40 and bought the same size as a previous Tommasini Sintesi, which was my last bike with a threaded steering tube. I used no spacers under the stem of the Colnago and a 110mm threadless stem with only a small rise to it.

You should select a Colnago so the reach and stack are the same as any other brand of bike that fits you well. The weight balance and steering geometry will be what they will be. If you don't like how the bike handles, then sell it and buy something with different geometry.

I've owned one Colnago and one LOOK frame at the same time. I used the same stem length on both and had no problem switching back and forth between the two. The front-center was 13mm longer on the Colnago. There was no need to buy a different size of Colnago. Just recently I sold that 16 year old LOOK frame and bought another Colnago, so now I have two.

Picking the right size is a lot easier these days, with most brands listing the stack and reach on their geometry charts. Unfortunately, Colnago doesn't list reach and stack for their classic frames. The 52cm Master is nearly identical to my current C-RS sloping TT frame. The head tube length of the Master, with the headset, matches. The TT length is only 3mm shorter, the STA is the same and the front center only differs by 1mm.

https://www.colnago.com/wp-content/u...RADITIONAL.pdf

Don´t Tommasinis also measure their frames c-t? The older 54 c-c Pinarello fits me right (i am a 53 on new ones) A 55 Tommasini would fit me perfect. Just like a Colnago 55 would. I don´t understand Look sizing.
I have been riding and buying high end bicycles for 25 yrs. I had a hard time liking some and began measuring to understand what was wrong. Front center has something to do. So is weight distribution, bb height. I can fit a shorter top tube frame w/ a longer stem as long as the front wheel stays where i like it to be.

[colker]

Originally Posted by wallymann

not true.



i have and actively ride a master, C40, C50, and ExPower...along with bottecchia, gazelle, trek, ciocc, merckx, atala, somec, dean, etc.

pick a colnago size based on the STA and TT combo that allow one to get into one's desired position (saddle height/setback + handlebar reach/drop) using one's desired stem length.

it is literally that simple. (as long as one doesnt have really unusual position needs). if one overthinks it, one risks "buying three diff. size colnago frames till they get the right one".

colnagos ride fantastically, there's no black magic in off-the-peg colnago geometry...it's all pretty common-sense stuff.

Colnagos are not imported around here so it´s hard for me to try one in my size. I am used to Pinarello but i pay attention to Colnago. I hear a lot about "picking the right size". They have slacker head angles than usual for sure.

[Dave]

Tommasini frames are measured C-T, but all that means is a 55cm measures 53.5 C-C.

Nearly every brand has now included stack and reach values in the geometry chart so it's much easier to compare frames sizes. The mistake that many people make is comparing two sizes of the same frame model and neglecting to correct the reach value to the same stack height on each frame. I assume that the smaller frame would have spacers added under the stem, or the stem angle changed to raise the bars. Either way, 3mm should be subtracted from the reach of the smaller frame, for each 10mm of stack height difference. Modern frames usually only come in 20mm stack increments and occasionally it's 30mm.

When stack and reach are available, the only use for the seat tube angle is to estimate the seatpost setback needed. In the small size that I ride, most frames have a 74-75 degree STA. If it's 75, I need to increase my post setback from 25 to 32mm. I get by with a 25mm setback with a 74.5 STA.

Some brands like Cervelo may use a 73 degree STA for all sizes, but they may also move the seat tube forward, so the center line does not pass through the center of the BB. I owned an early model R3. I disliked it so much that I only rode it twice. It was awful on a winding mountain descent.

[wallymann]

Originally Posted by colker

I have been riding and buying high end bicycles for 25 yrs. I had a hard time liking some and began measuring to understand what was wrong. Front center has something to do. So is weight distribution, bb height. I can fit a shorter top tube frame w/ a longer stem as long as the front wheel stays where i like it to be.

so you will actually change your riding position (saddle height/setback and handlebar reach/drop) so that the front-center is where you want it in relation to your body CG?

[colker]

Originally Posted by wallymann

so you will actually change your riding position (saddle height/setback and handlebar reach/drop) so that the front-center is where you want it in relation to your body CG?

The optimum front center and your position on the bike are two separate things. A bike that fits right leaves you relaxed, comfortable and better use your muscles. The wheels in the right place gives you perfect handling. Those two things work together because good handling leaves you relaxed.
You may adapt any bike to fit you but it may not handle the best if you are not weighing the wheels as it should.

The lower head tube and long flat stem flatten your torso and place your weigh over the front axle. You may feel inclined to move your saddle back or not if you lower your front. Fit is not static. It changes w/ time.

Some bikes fit you different than other and it does not mean it´s a wrong fit: the old fat chances had all 72 degr. seat angles no matter what size. Their handling was legendary.

[colker]

Originally Posted by Dave

Tommasini frames are measured C-T, but all that means is a 55cm measures 53.5 C-C.

Nearly every brand has now included stack and reach values in the geometry chart so it's much easier to compare frames sizes. The mistake that many people make is comparing two sizes of the same frame model and neglecting to correct the reach value to the same stack height on each frame. I assume that the smaller frame would have spacers added under the stem, or the stem angle changed to raise the bars. Either way, 3mm should be subtracted from the reach of the smaller frame, for each 10mm of stack height difference. Modern frames usually only come in 20mm stack increments and occasionally it's 30mm.

When stack and reach are available, the only use for the seat tube angle is to estimate the seatpost setback needed. In the small size that I ride, most frames have a 74-75 degree STA. If it's 75, I need to increase my post setback from 25 to 32mm. I get by with a 25mm setback with a 74.5 STA.

Some brands like Cervelo may use a 73 degree STA for all sizes, but they may also move the seat tube forward, so the center line does not pass through the center of the BB. I owned an early model R3. I disliked it so much that I only rode it twice. It was awful on a winding mountain descent.

Fine. Back to Colnago... how does that slack head angle works w/ the fork rake to make it handle like a road bike needs to? Some small frames have a 71.5 head angle! That´s a mountain bike head angle. I am fascinated w/ Colnago.

[Dave]

Colnago never lists the fork offset, but I have read that it's probably 43mm. I never give it a thought, since the handling is great. I'm comfortable at over 50 mph on a mountain descent. I'm sure it has more trail than some brands. More trail requires more force to make a turn and the bike has more tendency to stay on a straight line course, or return to a straight line after a turn. Some claim the additional trail is a problem at 5-6 mph, but I've never noticed it and I spend plenty of time climbing under 10 mph.

[Herder]

Thanks for all the info guys. Was not aware about the different ways manufacturers measure bikes.

I attached the Geo of the bike identical to what I ride . I ride a 56 with 100 stem. Only thing is I do have a large dust cap with a spacer. The headset is integrated so what you see is the full headtube length.

It looks like if I go on the smaller size of the master I would make the reach work with a longer stem as I am only using a 100 right now. It's just the drop will be to much. That too bad as I can get a deal on a 56 right now but I don't want the wrong size.

I'm thinking 57 or 58. I think the master comes with headset and dust cap? How much length does that add to the headtube?

[wallymann]

Originally Posted by Herder

...It looks like if I go on the smaller size of the master I would make the reach work with a longer stem as I am only using a 100 right now. It's just the drop will be to much. That too bad as I can get a deal on a 56 right now but I don't want the wrong size...

a few mm or whatever you need of spacers to get your stack where you want is fine!

as i mentioned i have a range of colnagos, including a master-x-light. all have the exact same position, but a couple require a few mm of spacers under the stem to achieve the to-the-millimeter consistency that i demand. ironically...the vagaries of artisanal construction methods being what they are...the varying spacers are needed despite all of them being 61cm frames!

Originally Posted by Herder

I'm thinking 57 or 58. I think the master comes with headset and dust cap? How much length does that add to the headtube?

that depends on the headset you use! the chris king 1" nothreadset upper bearing, for example, adds ~15mm to the stack. honestly, for external-bearing frames like the master the frame's stack should be *slightly* on the low-side and then you can add spacers as needed. my master happens to have a king 2-nut threaded headset, but the spacer logic applies.

[Dave]

The Cannondale geometry chart is helpful, but the combination of headset top cap and spacers, plus your stem angle would be valuable too. Most standard headset tops are 15mm these days, but adding 20mm of spacer would increase that to 35mm.

A standard Chris King headset has a stack of 28mm, to add to the head tube length listed in the geometry chart, but up to 20mm of spacers can be added without looking too dorky.

The 58cm traditional frame comes the closest to your 56cm C'dale. The top tube is 4mm longer, but the seat tube angle is .5 degree less, which means that the saddle would be a little further forward to place the saddle in the same position relative to the BB and offset the longer top tube. The minimum head tube length,with the headset would be about 179mm.

The problem with this size may be the standover height being too tall.

The shorter reach on the 56cm would require a 110mm stem since the steeper STA requires the saddle to be moved a 5-6mm further back on the post, but the head tube is 15mm shorter. Adding more spacers reduces the reach.

Back in the days when Colnago geometry was developed, the concept of frame reach was not in play and you often see very little difference in reach between two sizes, since the increase in TT length was at least partially cancelled out by decrease in the STA, as the sizes get larger.

https://www.colnago.com/wp-content/u...RADITIONAL.pdf

Here's a picture of my first C-40, a 55cm, probably from 2002. Back then I made the mistake of buying frames that fit my leg length better than my torso length, but I always used a setback seat post and a 110mm stem. Back then nearly all bars and the common ramp down angle that place the brake hoods lower than the top of the bars. These days, most bars place the brake hoods higher.



At the same time, I had just built up a new 54cm C-40 and planned to sell the first one.



Today, I ride what would be the equivalent of a 52cm traditional frame, but it's called a 48cm, based on the seat tube length. I use a lot more drop, but I could easily raise the bars by 2cm with a -6 stem instead of a -17.

[colker]

Another measure you could check is wheelbase. Check the wheelbase of the colnago 56 you have a deal on against your cannondale 56cm.
100mm stem is on the short side. Long stems add stability to a road bike. A -5 stem or even a 0 degr will raise the handlebar and you have spacers to fine tune.