Join Date: Feb 2016
Location: Budapest, Hungary
So I pulled out a brand new shock from a CBR500, and my trusty motorcycle shock spring compressors, and made a few measurements and observations.
The mark on the shock is a thin painted dot on both sides of the ring - so no wonder if after a few miles - and your prudent cleaning with the brake cleaner - itannot be seen.
The whole adjustment is a half turn on the crown or ring, indeed it has 9 settings (i'll call them 0+8), and it has the clear issue of being able to jump back to zero after the highest preload.
Given that the spring force is close to 90N/mm, and the total adjustment range of preload is ~6.4mm, it will slam down with roughly 580N, or about 59kg of force in an instant going from 8 to zero.
However, by design one cannnot jump from 0 to the 8th setting. So my advise is to adjust the shock to zero (by turning the crown to the right) until you cannot move it any further. Mark this position as this will be your base of counting.
If you want to experiment, try to ride on this setting for some time to get a feel of it.
Once you've read the linked material how to set motorcycle sag or you want to try to add some preload turn the crown to the left (you should feel definite steps as you turn the crown to the left) until you reach the setting you're looking for. I suggest to note it down where you are so next time you don't have to go back to zero to find where your actual position.
While I was there, I've done a few measurements.
Total weight of the shock is 2985gr.
Free length of the shock is 310mm, theoretical maximum stroke is 66mm - but the poly bush starts to engage after 40mm of travel, therefore 56mm of total travel seems to be more realistic.
By feel the shock has absolutely none or minimal compression damping and no gas preload.
Total preload adjustment range is 6.4mm in 8 steps (0+8 positions) or 0.8mm each.
Calculated spring rate is about 90N/mm (11.4mm wire diameter, 6 active coils, 80mm spring OD, what is tapering on both ends), so each preload step adds about 72N or 7.3kg of preload.
Hope this helps ;-)
Last edited by Oyabun; 11-11-2018 at 02:08 PM.