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Suspension Test

I know. Preload also alters ride height, but in this case the adjusters ONLY alter the ride height.
Normally most people measure the effects of preload adjustment by checking the distance between a cable tie tied to the stanchion and the bottom of the stanchion itself (on USD forks). That is fine for most bikes, but not for ZXR/ZX7Rs.
Try this:

Set the “preload” adjusters to min (fully out)
Tie a cable tie around one of the fork stanchions and push it up against the fork seal.
Stand the bike up without rider on board.
Measure the distance between the cable tie and the fork seal. We’ll call this measurement “A1”.
As a double check measure the distance between the cable tie and the bottom of the stanchion. We’ll call this measurement “X1”
Now sit on the bike in the riding position and have someone to hold you upright
Measure the distance between the cable tie and the fork seal. We’ll call this measurement “B1”.
Again as a double check measure the distance between the cable tie and the bottom of the stanchion. We’ll call this measurement “Y1”
Now wind the “preload” to Max (fully in)
As before measure the distance between the cable tie and the fork seal. We’ll call this measurement “A2”.
As a double check measure the distance between the cable tie and the bottom of the stanchion. We’ll call this measurement “X2”
Now sit on the bike in the riding position and have someone to hold you upright
Measure the distance between the cable tie and the fork seal. We’ll call this measurement “B2”.
Again as a double check measure the distance between the cable tie and the bottom of the stanchion. We’ll call this measurement “Y2”

In the second lot of tests, with “preload” on Max you would expect the sag to have reduced. However what you will find is that A2 and B2 will only be a couple of mm less than A1 and B1 (due to a shift in weight distribution towards the back of the bike). However you will see that X1 and Y1 will be considerably smaller than X2 and Y2. This is because, although the sag has not changed, it has moved further up the stanchion (i.e. Ride Height was increased).

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