# Need Help with measurement for 55 cm 585



## SJS (Mar 13, 2006)

Hi,

I am considering a Look 585 in the 55cm size. Only problem is I don't have any locally to test ride. I am working with a fitter to determine if it will fit, but we need to know the vertical distance from the ground to the top of the head tube (where it meets the top head set cup). Can someone please take a measurement of this for me?

Thanks!


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## C-40 (Feb 4, 2004)

*shouldn't need it...*

Your fitter must not know much about geometry. 

The head tube length is clearly listed as 156mm. The two LOOKframes that I have both came with an FSA headset that adds about 15mm to that length for a total of 171mm. The fork length is a middle of the road 368mm (also on the geometry chart).

What could be so critical that he can't figure out the fit? The info above should pretty much do it. 

I have two LOOKs with 120mm head tubes. The vertical height of the head tube is 79cm (no headset). The headset top section adds about 1.5cm. Measurements are at the center of the tube.

If the 55cm had the same head tube angle, it would be easy to just add 3.6cm times the sine of 73 (3.4cm) to yield a total of 82.4cm to the top of the head tube. The HTA is 1 degree steeper however. In theory, this would increase the height by .3cm. In total, I get 82.7cm to the top of the head tube (along the centerline). The headset will add another 1.5cm.


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