Frame size, new bike fitting, questions

[dogg]

hello, i am looking at buying a new frame but it comes in limited sizes and i am having trouble deciding which i should choose.

my current setup is as listed below and feels great, i wouldn't change a thing.

73°HT
73.5°ST
54.5TT
54ST (c-to-t)
150mm HT length
130mm x -17° Stem

the frame i am looking at comes in the sizes below

(small)
72.5°HT
73°ST
53TT
51.5ST (c-to-t)
100mm HT length

and

(medium)
72.5°HT
73°ST
56TT
55.5ST (c-to-t)
120mm HT length

i have not listed stack/reach because they are not listed for the second frame. BB drop is the same.

normally i would be able to figure this out on my own but I'm at a loss considering my current frame is basically exactly between sizes on the desired frame, and then angles and ht length come into play...

with the smaller desired frame id want a longer stem/reach, but how much longer with the much shorter headtube and slacker HTA??

and with the larger desired frame id want a shorter stem/bar reach, but the frame also has the slacker HTA and still a shorter HT?????? I'm just confused now

and for the record i am not concerned about my current road bike and the new "desired" bike fitting EXACTLY the same but i would like them to be close and not have big differences in handling.

any input would be appreciated, thank

[bungis]

I'm a huge believer in stack/reach, maybe you can calculate it?
http://bb2stem.blogspot.com/2011/10/sta ... -v100.html
http://bikegeo.muha.cc/

[Trumpets]

I am hoping for some comments reference the sizing for colnago c60.

I am 178cm in height with 84.5cm inside leg and I currently ride a large framed Holdsworth Stelvio which fits fine and has felt comfortable over 100 mile plus rides last summer, the dimensions are :

head angle 73 degrees,
head tube length 165mm, (run with 20mm spacers)
effective top tube 570mm, (run with 100mm stem)
seat angle 73 degrees,
seat tube centre to top 520mm,
stack 565mm and reach 397mm,
and 75cm from centre crank to top of seat.

I am looking at the colnago C60 54s, the geometry appears to match the above within 5mm here and there. (please bear in mind that the bike I'm looking at getting has the handle bars slammed on top of the head tube and the forks cut of above so no upward height can be gained), the C60s 54s geometry is

Head Tube Length 179,
Effective top tube 565mm,
Seat angle 72.83 degrees
seat tube centre to top 540mm,
stack 582 and reach 385mm

Does it appear that I have made the correct decision?

[soracabana]

Yes, it's correct!

[PSM]

I am 182 on a M10 52s...

[soracabana]

Too small or you have a special body.... Maybe small legs?

[PSM]

C60 54s is equivalent to a 58 standard. For 178 cm?!

[soracabana]

No, 565 length = 56

Trumpets is actually riding a 570 length, longer than the C60 54S

[TonyMM]

I am 170 cm and ordered a 48s (= 52 cm standard).

[soracabana]

Geometry doesn't depend only on the height but as well on inside leg, body, arms, femur, anatomy...

If trumpets ride a 52S C60, he will need more than 2cm spacers and a 120mm stem.

[PSM]

Mr. Short Leg

[PSM]

And my legs are 88 cm...

[soracabana]

Very nice bike with good proportions, congratulations.

88cm inside leg for 182cm height is long legs for a relative small sitting leight or relative short arms. So you are able to ride a small length bike with a short headtube because your body is supple. Even with these considerations, what is the distance between crankset axel and saddle? You should need 780mm at least and it seems you have actually approximately 760mm (20mm too small). I think your bike is too small, you need a custom bike.

Trumpets rides a 570 length bike with 163cm headtube and 2cm spacer and it appears that it's confortable for him. With a 565 length bike and 179 head tube he will have a shorter bike with a higher head tube that will be more confortable without any spacer.

[PSM]

When I ride my bike I feel very comfortable. Is that enough?

[soracabana]

Yes, that is enough of course. And that is the target for Trumpet as well. Maybe he should try a 54S and a 52S to be shure what is the best for him? What do you think about that solution my friend?