[QUOTE] My SV did My R6 did My ZRX did And the SZR is Italian.[/QUOTE] My CX did.
You should have said that "Almost *no* japanese motorcycle comes with a spanner to adjust the rear shock preload that isn't made of completely shite metal".
The preload is basically a ride hight adjustment. There are two drawbacks here. First, if you don't make a corresponding adjustment to the front end you change the steering geometry (making it slower steering). Secondly it will be easier to make the rear suspension bottom and that can be a problem if the roads are really bumpy and will not be nice to your back. The spring will be just as stiff after you reduce preload. Even so comfort may improve because after reducing the preload you will have more negative suspension movement available and this may (depending on if you had enough before adjusting) enable the wheel to follow the road better. It may and the only way to know is to test.
Previously on ukrm, Ace said... Steering head bearings? It doesn't matter to me, I have a multi-adjustable C-spanner for doing steering heads and shock preload.
Previously on ukrm, Dr Ivan D. Reid said... The earliest RD350 YPVS had a stupid toothed rubber belt to adjust preload, it usually broke the first time it was used.