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Discussion Starter · #1 ·
All,

I'm looking on purchasing a 585 and have a question on sizing. I'm currently riding a Colnago C40 pre B-stay model 51 cm. Dimensions are:

Seat Tube C-C -> 49
Top tube C-C -> 52.7
Seat angle -> 75
Head Tube lenght -> 9.6
HT angle -> 70.8

I use a straight seatpost with Koobi saddle almost all the way back and a 100mm Ritchey stem.

Looking over the 585 geometry, it appears that I'm somewhat in between the 49 and 51 sizes. Any suggestions?

Thanks,

Ian
 

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stole my name...

Man, you're giving me a bad name. C-40 knows the answers to questions like this. If you want the best setup, you need to include the amount of spacer you're using. You mention a Ritchey stem, but what angle? You're comparing a frame that uses a conventional headset (Colnago) to an integrated HS design, so the stack height difference need to be figured in the equation.

FWIW, the Colnago and LOOK c-c sizes are pretty comparable. Someone like me who might ride a 53cm (51cm c-c) Colnago would ride a 51cm LOOK. I do just that with a 51cm 585.

I'd say there is no question that the 51cm is too large.
 

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Discussion Starter · #4 ·
Sorry about the handle... Anyhow, I've got a WCS Ritchey stem 110mm with an 84 degree angle and about 3/4" of spacers. I've been looking at both the 49 and 51 585's. The 51 top tube is closest to my current ride although the seat tube is definitely slacker. I like that the head tube size, it would mean I would be using less spacers which would definitely improve the handling I believe. The 49 appears closer to my ride but I would probably be using the a similar amount of stack space. I'm using a thomson straight post with the seat all the way back. Thanks...

P.S. anyway to change my handle?

C-40 said:
Man, you're giving me a bad name. C-40 knows the answers to questions like this. If you want the best setup, you need to include the amount of spacer you're using. You mention a Ritchey stem, but what angle? You're comparing a frame that uses a conventional headset (Colnago) to an integrated HS design, so the stack height difference need to be figured in the equation.

FWIW, the Colnago and LOOK c-c sizes are pretty comparable. Someone like me who might ride a 53cm (51cm c-c) Colnago would ride a 51cm LOOK. I do just that with a 51cm 585.

I'd say there is no question that the 51cm is too large.
 

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stem length..

In the first post, you quoted a 100mm stem, now you say 110mm. Which is it? The Colnago's total head tube length with the headset should be at least 125mm, maybe 130, depending on the brand of HS. Add 2cm of spacer and you get a height of 145-150mm.

The 51cm 585 has a 125mm head tube, plus a 15mm topsection on the headset for a total of 140mm, so it would require 1-1.5cm less spacer. That will not make it handle any better. The 51cm will require one size shorter stem.

The 49cm has a 2cm shorter head tube, for a total length of only 120mm with the headset. It would require .5 to 1.0cm more spacer or a flipped 96 degree stem.

Do you have a saddle height measurement, from the center of the crank to the top of the saddle, along the center of the seat tube? FWIW, mine is 72cm. If your is much less, I'd go with the 49cm.

Alternately, you might consider the 555. It's a lot cheaper, rides better and it's got at least 5mm less reach.
 

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Discussion Starter · #6 ·
Thanks for the recommendation. My current setup is with the 100mm, but I'm trying out the 110 this week for an upcoming century. I've always felt a bit scrunched when in the drops and hope the 110 will give me a bit more room. As for seat height, I am at 65.5. My previous bike to which I was fitted on was a small LightSpeed sienna which had a 52.5 tope tube and 74 degree seat tube. That previous fit and this one is will at first I was thinking the 51 was a better choice. I'm waiting to see if the LBS can get a 49 and 51 for a better look see though I'm not hopeful. Most LBS's here can't afford to stock such small sizes (mostly 53 and ups in all brands). It's always hard to find a frame in my size on the top end brands - guess just not enough people of size venturing in to these places.

Thanks again...

C-40 said:
In the first post, you quoted a 100mm stem, now you say 110mm. Which is it? The Colnago's total head tube length with the headset should be at least 125mm, maybe 130, depending on the brand of HS. Add 2cm of spacer and you get a height of 145-150mm.

The 51cm 585 has a 125mm head tube, plus a 15mm topsection on the headset for a total of 140mm, so it would require 1-1.5cm less spacer. That will not make it handle any better. The 51cm will require one size shorter stem.

The 49cm has a 2cm shorter head tube, for a total length of only 120mm with the headset. It would require .5 to 1.0cm more spacer or a flipped 96 degree stem.

Do you have a saddle height measurement, from the center of the crank to the top of the saddle, along the center of the seat tube? FWIW, mine is 72cm. If your is much less, I'd go with the 49cm.

Alternately, you might consider the 555. It's a lot cheaper, rides better and it's got at least 5mm less reach.
 

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Alternately, you might consider the 555. It's a lot cheaper, rides better and it's got at least 5mm less reach.[/QUOTE]



Hi C-40
Why does the 555 ride better than the 585? Just curious since I have one.
 

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different construction..

The 555 is an upgraded version of the 461, which I also have. The 585 is just plain stiffer and I know this because I've got one. I'd credit the BB area and the seatstays, but it's also made out of VHM carbon.
 

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65.5??

Are you sure about that, measuring from the center of the crank to the top of the saddle, along the centerline of the seat tube? If it's accurate then the 51 would be way too large - don't even bother looking at it. You must also have very little drop from the saddle to the top of the bars. Have you ever had a real fitting?
 
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