Colnago C64 Fit Question

[edwardk]

Greetings all. I've learned a great deal from the "Colnago C64 First Look" thread, but have a question that I don't think has been answered there; in light of that thread's length, and the possible relevance of my question to other Colnagos, I though it would be best to post as a new thread.

It's great that Colnago offers 14 (!!) sizes for the C64, in two different configurations (H and S) but unsurprisingly there's some overlap between the configurations that leaves me puzzled. I'm 179cm tall, long legged for that height, and ride in a relatively relaxed position suitable for a man of my age (which at least remains in double digits). If I think in terms of stack and reach, a bike with a stack of 580-590mm and a reach of 380mm would be ideal. My current bikes fall squarely in that range; with a 580 mm stack height I might use 10-20mm of spacers, depending on how (relatively) aggressive I want to set up the bike, etc.

The 52H and the 54S both fall roughly within that range. The 52H has a stack of 579mm and a reach of 379mm. The 54S has a stack of 583mm and a reach of 585mm. So how does one choose between them? Looking at the geometry charts, one obvious difference is seat tube height -- 52 vs 54cm. The 54S thus (ironically?) would be a bit less sloping in looks than the 52H. The seat and fork angles are closer to parallel in the 54S, which I think aesthetically looks a tiny bit better. But are there differences in handling or weight distribution that I am not intuiting from the charts? At these prices this would be an expensive mistake to make!

[MJB]

I qualify my answer by saying subjectivity is all I can offer, my back and hips are not particularly flexible and inseam / leg length measurements between two riders of identical height can vary.

I'm also 179cm, set my bikes up as upright as possible and cannot cope with the reach of a Colnago 54s even with a 90mm stem and a zero setback seatpost. Not even 9 years ago when I was fitter and more flexible could I go long distance on a 54s.

I have owned a pair of tube and lug Colnago 52s framed bikes and ridden a friend's 52s frame for good measure (all same geometry as the current C64 sizings) I find the 52s a comfortable match for me in both reach and stack.

Colnago tube and lug sloping frame geometries are aesthetically the best looking sloping frames I have ever come across - lacking the dramatic steep angles and arched curved top tubes of other companies offering and as close to the truly lovely old school traditional geometry horizontal top tube frame appearance as I can get in a sloping geometry.

I cannot comment on the newer 'H' frame sizings.

[edwardk]

Thank you -- this is very helpful! I share your lack of hip/back flexibility.

[silvalis]

At these prices, would you not pay a professional to at least aid you?

[edwardk]

Thanks. I have been professionally fitted, and am comfortable with the stack and reach figures I mentioned. My experience has been that fitters won't necessarily know as much as the denizens of this forum about the differences between the two frames, and that dealers will be sure to recommend whichever one they have in stock. Hence my question here.

[r4nd0mv4r14bl3]

I qualify my answer by saying subjectivity is all I can offer, my back and hips are not particularly flexible and inseam / leg length measurements between two riders of identical height can vary.

I'm also 179cm, set my bikes up as upright as possible and cannot cope with the reach of a Colnago 54s even with a 90mm stem and a zero setback seatpost. Not even 9 years ago when I was fitter and more flexible could I go long distance on a 54s.

I have owned a pair of tube and lug Colnago 52s framed bikes and ridden a friend's 52s frame for good measure (all same geometry as the current C64 sizings) I find the 52s a comfortable match for me in both reach and stack.

Interesting. Reach of 54s is just 1mm longer than 52s. Assuming you get the saddle in the same position as with 52s, the larger frame should allow for a more upright position with the same amount of spacers.

[AJS914]

I'm 183cm and ride a 52S. I straddled a 54S at my dealer and it just felt a bit big for me. I know I could ride it just fine but I'd rather go with the smaller, more nimble frame given the choice. If you need spacers then the 52H seems like a logical choice.

Go ride any 52S and 54S at your local dealer and see for yourself.

[guyc]

Apologies for jumping in here but I’m also a bit puzzled by their sizing.

I’m looking at a C64. I currrently ride a Canyon Ultimate CF SLX in large (roughly a 58). It fits very well. I’m 6’1” with a 34” inside leg. This frame has a stack of 592mm and a reach of 399mm. I run a 110mm stem. Retul fitting confirmed this size before I went ahead and ordered a few years back.

Looking at the sizing for a C64 the 56 would be close to that with a stack of 591mm and a reach of 398mm.

Am I right or missing something obvious to those of you more familiar with their sizing. Most people seem to go down 2 ‘sizes’ compared to other makes but going to a 54 would give me a stack of 583mm and a reach of 385mm. Quite a difference to what I have now.

[Calnago]

For me, it’s a no brainer which size C64 I would get. At just shy of 6’1” (184cm) with a 905mm inseam, I’d have a 56s set up just perfect. Traditional sizes I fit just fine on are 59 or 61, and if they made them, a 60 (equivalent of 56s). But everyone is different.

[MJB]

But everyone is different.

This - salient point.

I was professionally fitted to a frame that ended up being not one but two sizes too large for my liking. I'm a recreational rider seeking comfort. The more comfortable I am the longer I can ride. I am not an athlete.

I believe I was fitted up to a specification using tried and tested formulae that work well for fit riders with flexible bodies who want maximum efficiency. We are, after all, talking about road racing bikes here.

I want to ride a racing frame as a recreational ride so I'm different and it took me a few builds and my own intuition to make my bike 'just so'

[beeatnik]

You should get a 54S and run a 100mm. That's what Mr. Colnago would put you on. I know that because I have a riding partner who is "179cm tall, long legged for that height, and ride(s) in a relatively relaxed position." Ernesto Colnago fit him to a 58 traditional which is the equivalent of a 54S.

Here he is on the bike w/ 10mm under the stem.

[AJS914]

I was professionally fitted to a frame that ended up being not one but two sizes too large for my liking. I'm a recreational rider seeking comfort. The more comfortable I am the longer I can ride. I am not an athlete.

I believe I was fitted up to a specification using tried and tested formulae that work well for fit riders with flexible bodies who want maximum efficiency. We are, after all, talking about road racing bikes here.

I want to ride a racing frame as a recreational ride so I'm different and it took me a few builds and my own intuition to make my bike 'just so'

If you want to ride a racing bike and sit upright with very little saddle to bar drop then you do need to upsize to increase stack. It's either larger frame (assuming reach is ok) or a smaller frame with lots of spacers or an upward sloping stem or both.

This used to not be an issue when stems were adjustable and it's further complicated these days now that spacers aren't cool or "pro".

[vinc]

Hi, for your information. I’m 5.7ft/1m74 and riding a 50s C60 with a 120mm Deda zero100 stem with the low headset cup and just 2mm spacers. Saddle height is about 73cm.


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[leungti1]

You should try the fit calculator below and get to identical stem reach/stack of your current bike using geometry of both 52H and 54s based on different stem length and spacers. Just comparing frame stack/reach can be misleading as they are based on different headtube lengths. The only thing it does not calculate is your saddle position. Colnago used to publish setback number (Scs) for C60 but no more for C64. But it's reasonble to assume 54s has 1cm more setback vs. 52H. So make sure you get the seatpost with the right setback as C64 comes standard with 1.5cm setback but can order posts with either 2.5cm or 0cm setback.

http://www.bikegeo.net/

[fromtrektocolnago]

Thanks. I have been professionally fitted, and am comfortable with the stack and reach figures I mentioned. My experience has been that fitters won't necessarily know as much as the denizens of this forum about the differences between the two frames, and that dealers will be sure to recommend whichever one they have in stock. Hence my question here.

a good fitter will not only measue you but check your flexibility. i had a fitting done yeas ago and flexibility was certainly part of the expereince.