Colnago Traditional Geometry Question

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Mr.Gib
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by Mr.Gib

Hi All,

Mr. Gib (183 cm/6 feet, 176 cm saddle height) is all tangled up in getting his hands on an Extreme Power. I have not signed on the dotted line yet so I wanted to explore a geometry question.

The 58 cm size seems text book perfect as far as the length of the bike goes. With a seat tube angle of 73 degrees and a top tube of 56.3 cm, this is pretty close to just about every other bike I have ever owned. With my slightly longer that average torso and long arms this will mean a 120 mm stem or maybe 130. On paper the correct fit.

The thing that has me second guessing is that I will be using a CK headset that I understand will add 3 cm to the 16.5 cm head tube. So I'll end up with an effective head tube length of 19.5 cm. This sounds a bit tall and when combined with the big 70 mm bb drop. Totally slammed I should be fine.

But what about going to a 57 cm frame? 55.6 cm top tube, 15.8 cm head tube (equal to 18.8 with headset). Just seems a bit short in the reach department. Certainly would require at least a 130 mm stem.

I am not looking for a super aggressive fit. I prefer about 10 cm of saddle to bar drop. With that setup I can ride for hours in the drops if I have to. (Bars are short and shallow.)

I guess I would be fine on either size and would have no problem getting my ideal position - the differences are so small between the two. But if anyone has wisdom on this situation I would be most appreciative. (Thanks to Calnago for already weighing in, but I'm still hungry for info.)

TKS,
Mr. Gib.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

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MJB
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by MJB

This is a somewhat subjective question as Colnago does offer so many minor size increments, esp. with traditional horizontal top tube frames - both a luxury and a conundrum if you havn't sampled all the relative sizes in your range......

I'm 179cm tall and found my EP in size 56 trad just a tad too large for my liking - despite 56 being inside what conventional fitment guides might suggest. I ran both a 100mm 6 degree and a 100mm 17 degree stem with variable risers from 10mm to 15mm sitting on a 15mm setback post - and for me the reach to the bars was just ever so too far for me to be comfortable for more than 5-10 min. at a time which is not how most my other builds have felt.

I experiented with a zero setback post which made the reach very do-able for me but my body felt like I was now too far forward of the BB and when I wanted to push hard on the pedals I found that I was sliding back onto the rear of the saddle to make those effort strokes and my hips did not agree with zero setback. I even fiddled with saddle rail position a little at a time but after the best part of 10 rides making one small adjustment at a time and sometimes adjusting on the road, I just felt the bike fit was not quite right.

In comparision I have a Colnago Master X in size 54 traditional and I find it the perfect fit from me, admittedly I ride it as a pleasure bike and for recoveries the next day so no real training type efforts, but 54x54 with a 105mm stem suits me perfectly, it's the only bike I've ever built that I have thrown a leg over from stratch and never made more than the rare finest of adjustments to.

Everyone is different, every Colnago size is different, despite the relatively minor incremental size differences. Based upon my own experience, I'd say you at 183cm might want to think hard about a 57 trad....... but then again, everyone is different and a 58 is not by any stretch out of your size range.

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Mr.Gib
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by Mr.Gib

MJB, interesting. I would think a 56 traditional would be manageable at your height. Are you longer in the leg and shorter in the torso and arms? That would explain things.

I have a Parlee Altum ML that fits very well. It has nearly the same dimensions at the 58 traditional. Top tube is 3 mm shorter, but everything else is about the same. I need a 130 stem on the Altum and find the front end a tad high with the medium headset spacer. (I don't use the short spacer because it makes the bike look like crap. Altum owners will know what I mean.) I have no problem reaching the hoods and could happily ride with an even longer stem.

And yup, the sizing options for older Colnagos is endless. Lack of stack and reach data adds to the challenge.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

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MJB
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by MJB

Mr.Gib wrote:I would think a 56 traditional would be manageable at your height




Yes, so did I...... and yes I have a very short torso compared to my legs. I also have a slight disc bulge between L3-L4 which has been settled for the best part of 2 years straight without pain or discomfort however I may have lost something in that time. I know I've also shrunk 4mm in height in the past year and have lowered my saddle height as efficiency is not my thing, I'd remain comfortable for the whole ride.


To diverge slightly from trad frame size discussion, I felt really well fitted to a Colnago C50 and my friend's EP- both of these in size 52s. These frames are close enough to being the equivalent of a size 56 trad. However, when it came down to the ride I just could not get myself comfortable for longer stints than an hour or so on a size 56. During the time I was riding my size 56 trad I switched between it and my friend's 52s EP and my own 54 trad Master. Numerous tape measure session and adjustments later I came to the conclusion that although a 56 trad is very close to the 52s, for geometry reasons that are beyond my caring the 54 trad and the 52s suit me better.

Your Parlee with a 130mm stem would most likely feel like two sizes too large for me. I suspect you are more flexible and have a stronger core than I do.

DJT21
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by DJT21

Horizontal top tubes need a negative 17 degree stem to look right really. A negative 10 is not too far off either. A negative 6 looks stupid IMO.

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Mr.Gib
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by Mr.Gib

MJB wrote:
Mr.Gib wrote:I would think a 56 traditional would be manageable at your height




Yes, so did I...... and yes I have a very short torso compared to my legs. I also have a slight disc bulge between L3-L4 which has been settled for the best part of 2 years straight without pain or discomfort however I may have lost something in that time. I know I've also shrunk 4mm in height in the past year and have lowered my saddle height as efficiency is not my thing, I'd remain comfortable for the whole ride.


To diverge slightly from trad frame size discussion, I felt really well fitted to a Colnago C50 and my friend's EP- both of these in size 52s. These frames are close enough to being the equivalent of a size 56 trad. However, when it came down to the ride I just could not get myself comfortable for longer stints than an hour or so on a size 56. During the time I was riding my size 56 trad I switched between it and my friend's 52s EP and my own 54 trad Master. Numerous tape measure session and adjustments later I came to the conclusion that although a 56 trad is very close to the 52s, for geometry reasons that are beyond my caring the 54 trad and the 52s suit me better.

Your Parlee with a 130mm stem would most likely feel like two sizes too large for me. I suspect you are more flexible and have a stronger core than I do.


Yup, I think your issue is the result of your proportions and injuries. Many years involved in certain sports has left me with a damaged spine as well. But for me, I feel just as good with my back horizontal as I do when sitting upright. Sometimes I get relief by stretching out and resting my forearms on the bars (less vertical compression on my vertebrae). It probably helps that I am very flexible and still very strong on the bike for an older guy. I still do a fair bit of training with Cat 1's and 2's. But getting dropped more often as the years go by :cry:
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

BdaGhisallo
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by BdaGhisallo

If this a frame that uses a traditional external cup headset, isn't some of the stack height you mention for the King HS already factored into the design of the frame, especially the lower cup? I would think you only need to worry about the King if its stack height is significantly different from another HS you might use or that Colnago designed the front end to use.

Fiery
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by Fiery

Colnago has relatively shallow head tube angle and thus relatively long front center measurement when compared to an average bike with the same top tube length. If I was buying a Colnago, I would expect to have a top tube that's 5-10 mm shorter than my current bike (and a suitably longer stem) in order to keep the wheelbase and the weight distribution between the wheels where I like it.

I'm actually of a similar height to the OP, and I would personally be looking at sizes 56 and 57 with a 130-140 mm stem.

mrd
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by mrd

My extreme power was a 54 c-t traditional and I'm 5'9" and "normal proportions, ("regular" inside leg in trousers) . it was my favourite bike ever!! i still have a c40, same geometry and size and an original master olympic 55cm which i now feel is just too big. on a modern sloping top tube a 50s would be fine. A 52s would be bearable, just, but would mean short stem ( 110mm on my ep) and/or inline seat post (25 mm layback on Colnago carbon seat post that matches the graphics on the star carbon fork), slammed stem or low stack headset top bearing cover and even then the saddle to bar drop would be less than ideal, very little seat post visible and just looks too "big" and upright, compared my size 54/medium s-works tarmac and venge.

having said all of the above if i could find an extreme power in the gloss carbon no paint finish, i would chop the relevant bits off my body or get extensions to arms and legs because it was just wonderful..... until i and it got driven over by a local driver. I still have the star carbon fork, matching seatpost and record 10 groupset and fulcrum racing zero wheels to put back on my impossible to find replacement frame. I have been looking for 2 years!!!

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Mr.Gib
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by Mr.Gib

BdaGhisallo wrote:If this a frame that uses a traditional external cup headset, isn't some of the stack height you mention for the King HS already factored into the design of the frame, especially the lower cup? I would think you only need to worry about the King if its stack height is significantly different from another HS you might use or that Colnago designed the front end to use.


King is one of the bigger headsets as far as stack goes (adds 30 mm I'm told) but apparently not so different from others that it matters. Yes, of course factored into frame geometry.

Fiery wrote:Colnago has relatively shallow head tube angle and thus relatively long front center measurement when compared to an average bike with the same top tube length. If I was buying a Colnago, I would expect to have a top tube that's 5-10 mm shorter than my current bike (and a suitably longer stem) in order to keep the wheelbase and the weight distribution between the wheels where I like it.

I'm actually of a similar height to the OP, and I would personally be looking at sizes 56 and 57 with a 130-140 mm stem.


Very good observation on the head angle. Aprox 72.5 degrees in my size. Compared to the more standard 73 and occasional 73.5 (my ML Altum). I think a longer wheelbase (with possibly quicker steering) is exactly what I am looking for. Assuming equal fork geometry, I find 73.5 head angles result in steering that is just a bit slower than I like, and require more overall bike lean in extreme cornering situations. I know why Parlee did this and it has it's benefits. The average doctor or lawyer that buys a Parlee can cruise down the street in a nice straight line without paying attention. Phenomenally stable and predictable handling in any situation for such a light, stiff, quick, tossable bike, but to me it feels a bit neutered in the handling department. And the toe overlap with my big feet is silly.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

Fiery
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by Fiery

I'm confused. Assuming equal fork geometry, a slacker head tube will produce a longer trail measurement, that will in turn make the steering feel slower. A longer wheelbase will also make the bike hold a straight line better, and feel less eager to corner. I don't think going with a slacker head tube angle plus a longer wheelbase will result in quicker steering in general.

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Mr.Gib
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by Mr.Gib

I am always confused about steering. Perhaps "quicker" and "slower" are not the right terms.

There is a difference between how a bike responds to turning the handlebars and how it responds to being leaned over. When I lean a bike over I really want it to turn in and carve. A bike with a slacker head tube angle should do this better, which is what I am seeking.

This might help explain further: http://calfeedesign.com/tech-papers/geometry-of-bike-handling/

Either way I am betting that I will be pretty pleased with Colnago geometry and steering feel.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

Fiery
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Joined: Sat Mar 16, 2013 9:21 am

by Fiery

I very much agree about there being a difference between how turning the handlebar feels (I refer to that as "steering") and how the bike feels when leaned over, and especially how it responds to moving your weight around (steering from the hips).

How long are the chainstays on your Parlee?
Last edited by Fiery on Mon Feb 13, 2017 1:20 pm, edited 1 time in total.

BdaGhisallo
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by BdaGhisallo

http://www.velonews.com/2017/02/bikes-a ... tly_430274

Here's a great insight into steering geometry and its effects.

Fiery
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by Fiery

He wrote that whole response focusing on the front end geometry alone, yet the differences in handling the reader described could have also come from the differences in BB drop, or chainstay length, or a combination of various other factors. From personal experience, my 59 mm trail bike is noticeably lot more agile or "maneuverable" than my 54 mm trail bike, and that's because they differ in more than just the trail measurement.

There is very good info there, but it's incomplete.

by Weenie


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