# Help me figure this damn geometry and save my colnago



## ronderman (May 17, 2010)

OK, here is the deal. I have 3 bikes - A Merckx SC, a Colnago EPQ and a Cannondale CAAD 10. I've had cannondales forever and can get them dialed in - have owned over 10 of them. The geometry is very, very similar on all 3 bikes except the Merckx is a bit more laid back and has a massive slope. I have the same post, a 3t straight post, except for the colnago which came with a slightly laid back post. Here is the deal, on the colnago my reach is almost 4cm more! It's too far out there. I've posted the geometry for all 3 bikes - does anyone see anything big on the geometry? Could it be just the post? Are any colnago owners changing their post that came with the frame?

This is driving me insane - here is the geometry

Merckx
54cm Seat Tube (center to center)
59cm effective seat tube
59.5cm effective top tube
198mm Head Tube
6cm spacers, headset and stem (measured top of headtube to top of stem)
3T 120mm stem - 6 degree rise
saddle drop - 4.25"
seat angle 71
setback 19.0
Straight 3T post
Saddle to Bar Reach 60cm

Colnago
58cm Seat Tube (center to top)
62cm effective seat tube (center to top of the virtual seat clamp)
59cm effective top tube
204mm head tube
7cm spacers, headset and stem (measured top of headtube to top of stem)
Dead 120mm stem 0 degree rise (or negative 17)
saddle drop - 3.25"
seat angle 72.75
Colnago Laid Back post
Saddle to Bar Reach 64cm

Cannondale
58cm Seat Tube (center to center)
60cm effective seat tube
59cm effective top tube
190mm Head Tube
Stems and spacers TBD
Seat Angle 72.5
3T Straight Post
Saddle to Bar Reach 60cm


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## Evil Laugh (Oct 9, 2009)

Have you got the same saddle on each bike and the same setback on the saddle (distance from nose of saddle to vertical line though center bb)?

You should have this or equivalent (different saddles measured and setback adjusted to compensate for different length) before comparing reach from saddle.


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## Evil Laugh (Oct 9, 2009)

My advice is take the bike you like the fit of. Take the saddle height and saddle setback measurements from the bb. Measure the drop to bars from the saddle using a level, measure the reach to bars from saddle nose. You ideally need the line though the axles to be level. 

If you use different saddles, mark the saddle on the rails where it is clamped so you know the fore aft. Take the saddle off this "good fit" bike. Put it on the Colnago. Set the saddle height and setback from using those measurements taken from the good bike. Then set the bar height from saddle. Then you can assess the reach from saddle to bars which is adjusted by stem length and angle of rise/spacers. Set this as close as you can (you might not be able to get it mm perfect due to stem size intervals) and see if it feels better, it should do. 

This link is somewhat useful for working out what stems you need, you can see how the angle/spacers affect reach..

Stem Comparison Tool | yojimg.net

I'm assuming you are measuring reach to the bars where they are clamped at the stem, center of bar. 

I can't see how you won't be able to get the same fit on the bikes. My guess is your saddle setback is inconsistent. All you need to do is set the saddle in relation to bb and bars in relation to saddle. Keep that triangle consistent between all bikes. Ideally use the same bars, saddles, lever style and crank length on each bike as they all affect the fit. 

Always work in that order BB --> saddle --> bars. Saddle position is the key to fit. Double check measurements as you go as, for eg, adjusting saddle setback affects the saddle height and vice versa, same with stem length/drop to bars etc. To keep saddle height measurement constant always measure through a constant line, eg center line of seatpost, to a constant point, eg bottom of spirit level rested on saddle with saddle level or at desired degree of tilt. 

You will get all those bikes to fit the same, the difference will be stem length/angle and spacer stack and whether the configuration is acceptable to your handling desires. Maybe you will have to use an inline post on the EPQ. Some saddles have the rails so far back on the saddle that this is necessary for some people. Personally I can't use a fizik saddle on a 25mm setback post (on a 73.5 STA which is usual for my size bikes) as I can't move the saddle forward enough.


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