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Kg 361 vs. lemond Zurich geometry(5 posts)

Kg 361 vs. lemond Zurich geometrySub
Feb 9, 2002 9:39 PM
need help comparing geometry of these two frames. I know a size 51 zurich is what I need, not sure if a 50 or 51 361 will work. I believe they have similar seat tube angles, but can't determine stand over height on the kg, their chart is confusing. No local shops carry looks, so had fitting on zurich done.

http://www.lemondbikes.com/tech-center/tech_geometry.html

http://www.totalcycling.com/Merchant/De_Rosa_Colnago_Look_frame_geometry.htm

Thanks
The KG361 Geometry is...Dave Hickey
Feb 10, 2002 6:16 AM
Not the same as what's posted on Total Cycling's web site. Total has the LOOK KG281 geometry. Go to www.lookcycle.com for the KG361 geometry. The 50cm frame has a top tube lenth of 53.8cm and the 51cm has a top tube length of 53.9cm. That number is so small of a difference it really comes down to stand over height. Is the Lemond geometry center to center or center to top? If its center to center, get the 51cm LOOK. If the Lemond measures center to top, get the 50cm LOOK. FYI, I'm 5'7" with a 30.25" inseam and I ride a 51cm LOOK but I also own a 49cm LOOK that fits me just as well.
geometry comparison...C-40
Feb 10, 2002 6:17 AM
The LOOK geometry chart is about as clear as any could be, although they don't list standover height or bottom bracket height (or drop). Standover height should be very close to the Lemond, since both are measured center to center. Standover height isn't critical unless you're trying to buy the largest frame that you can safely straddle, for some reason. What is important is the seat tube angle, the top tube length and the head tube length.

The 100mm head tube length on the Lemond is 1.5mm longer than the Look's 98.5mm, which is pretty insignificant. I would compare these lengths to your current bike to be sure it's appropriate. With the use of threadless stems, it's become more important to pay attention to the head tube length to avoid the use of too many steering tube spacers. The head tube length is one of the first things I look at when judging the vertical size of a frame.

The Lemond has a .75 degree steeper seat tube angle than the LOOK, which effectively lengthens the 53.2cm top tube by .9cm to 54.1cm, compared to the Look's 53.9cm. This is an insignificant difference.

In summary, these two frames are about as identical as they come.

What I also recommend as a guide for the proper vertical size is measuring saddle height above the top tube. A common range is 15 to 20cm. This is a large range, but covers everyting from the touring fit (15cm) to a radical racing fit (20cm) and a broad range of frame sizes. The saddle on my 55cm (c-t) frame is only 17cm above the top tube and still has a relatively large 10cm drop from the top of the saddle to the top of the bars, using an 80 degree stem with no steering tube spacers.
geometry comparison...Sub
Feb 10, 2002 10:27 PM
I appriciate your help guys, it has cleared some things up. The problem I have with the look geometry chart is the letter system, dont know which measurement stands for what, I can figure some of them out, but the lemond,trek geometry charts spell it out quite clearly for you. The only real difference I see between the 50 and 51 Look is the head tube height, correct me if I'm wrong.

thanks

Sub
correct...C-40
Feb 11, 2002 5:40 AM
There is an insignificant difference in top tube length, but the 1cm shorter head tube length is significant. Nothing looks worse than a frame that's too small, with lots of steering tube spacers and/or a high rise stem making up for the mistake in size selection.

As long as you have 2-3cm of standover clearance (to hard contact) you're OK. More clearance will only cause saddle to bar height problems.