Giving the 7/9R some Pre-load

ALL questions, technical and otherwise answered for Other Models and Marques .

Moderators: RAFlyer, yorkie, tangosevern, Steve-TC1

Post Reply
User avatar
shamus13
Moderator
Posts: 5666
Joined: Mon Sep 18, 2006 9:13 pm
Location: HULL
Contact:

Giving the 7/9R some Pre-load

Post by shamus13 » Thu Nov 19, 2015 9:55 pm

Despite the almost universal praise for the ZX7R's front end it may come as some surprise that the forks don't actually come with a pre-load adjuster, just rebound and compression. The fork cap has what looks like a pre-load adjuster but in fact it adjusts the fork height. Time to give it some pre-load :!:

Image

In the standard setup with the spring resting as in the above picture, when the adjuster is turned the damper rod and spring don't actually move, instead this action lifts the outer fork leg up thus increasing fork height. To give the fork pre-load the spring pressure needs to be off this adjuster allowing it to turn inside the spacer and offering no resistance to the spring top. With this setup it works in reverse to the usual pre-load seen on most bikes but pre-load all the same. The adjuster turned fully in you are actually at it's softest setting. By winding the adjuster out it now only pulls upward the damper rod instead of the rod and the spring. So whereas before the rod and spring moved up and down remaining a constant now the damper rod pulls on the spring. With the spring remaining static at the top this pulling on the spring gives you the pre-load and spring tension without movement of the fork outer. Anyhow, the pics may help explain it better than my waffling :roll:

Image

Image

Image

Image

Image

Image
SHAMUS

BEX MOTO

"If you can't express it in numbers it's not engineering, it's opinion."

User avatar
MattyLawsRacing
Mechanic
Mechanic
Posts: 72
Joined: Mon Oct 19, 2015 4:43 pm
Location: Hull C2

Post by MattyLawsRacing » Fri Nov 20, 2015 8:39 pm

Cracking thought process there shamus!

Good work bud.

Will look forward to hearing how she rides next year.
Go check out my racing page
http://mightykwacker.blogspot.co.uk/
Matty laws racing #193
Racing a zx9r c2

MIGHTY KWACKER BLOG and INSTAGRAM

Post Reply