Look 585

[chismog]

Originally Posted by slowpoke

Can someone check my math here?

According to Geometry Geeks, the Look 585 in a medium supposedly has a reach of 386mm: https://geometrygeeks.bike/bike/look-585-2008/

Checking the geo chart, and calculating it, I get a different reach.

585 geocharts:
https://ep1.pinkbike.org/p4pb14497764/p4pb14497764.jpg

This should just be virtual top-tube - setback from BB (B - E), right?

Calculating my own E here:

sin (90º*- STA) * A1 - we want A1 because it meets with B in the diagram
= sin (90º - 73.73º) * 530
= 0.27982901 * 530
= 148.3mm - this matches up with the E in the chart

The virtual top-tube B is 545mm.

545 - 148.3 = 396mm for reach.

This seem right? Thanks!

I didn't check your math, but I did check your variables. In the chart, there are three lengths shown for seat tube. There's a mistake in the chart!

A1 cannot be longer than A as shown in the drawing. But it is in the chart. Comparing this against my own 585, I see that in reality:

A1= Actual, center to top
A2= Actual, center to center
A= Virtual (traditional size), center to center.

So my my large is 53.5 to top, and it fits about like a 55-56.