Rear shock preload and ride height question

testrider · 12-08-2006, 3:20 PM

Hi all,
Is jacking up the rear preload 6mm higher, let's say with an Ohlins' remote preload adjuster, the same or almost the same as adding 6mm shim?

Thanks.

ConqSoft · 12-08-2006, 4:13 PM

Should be the about the same.

testrider · 12-08-2006, 5:21 PM

Thanks. So when I get my Ohlins, I shouldn't have to shim with a 6mm washer. Correct? Right now I have a 6mm shim on my stock shock to raise the ride height.

HERBXX · 12-08-2006, 6:12 PM

It would have a similar effect on the turn in speed ect , but it will also make the ride harsher , cause it will take more force to make the shock start to compress if you crank the preload. If the the new shock comes with correct spring rate , so the sag is corret without without using the excessive preload . I would still use the spacer if it was mine.

Herb

testrider · 12-08-2006, 6:23 PM

Thanks for the comment. The reason I asked was after raising my ride height 6mm, it's not very stable at high speed. So with an Ohlins and no shim, I'm going to run it in stock height most of the time until I want the quick turn in then I can dial in 6mm more preload.

HERBXX · 12-08-2006, 6:33 PM

It all about compromise. Read up about the the increased preload might or might not do to your rear traction. Every change has some effect and as long as you have an idea of what to expect you will get along fine. I have never used a spacer but now that i have botheends sprung and damped close to how i think i like it after a couple of years of playing around , might try a 3mm one next year . It took me a couple of trys to get the internal damping of my shock close enough.

99Birdman · 12-08-2006, 7:27 PM

It will absolutely not be the same. Preload adjustment is designed to accommodate differences in rider/bike weight within the range the chosen spring/shock combo is design to operate. As Herb said, it is used to set the appropriate sag and allow the suspension to operate within it's optimum range. The Penske shock with adjustable preload also has adjustable ride height via lengthening of the shock shaft which would have the same effect as adding the shim. In fact, given the amount of travel available in the shock, I don't believe it would be possible to achieve the same difference in ride height (about 1.25") as adding 6mm shims.

testrider · 12-11-2006, 1:46 PM

Thanks! I'm going to shim 6mm if I get the Ohlins.
Originally I was confused with "shimming 6mm" and "adding 6mm preload".
They are not the same!

jmguild · 05-17-2008, 1:28 PM

I've just been on the Ohlins web site. Latest models have adjustable ride height +/- 10mm which is independent of spring preload adjustment.
Based on that, you should be able to throw your shim away.