Sonic Springs / Spacers ST1100 ABS

Hi.

I have just received my new Sonic 1,2 springs, for my ST1100 A '93
Removed the old springs , and discovered that only the left side having a spacer.
Measured the old (Not OEM ? ) front spring free length to 473 mm. (About 18,65 in.) Clymer say that is the same length as the original.

The instruction from Sonic Spring was to put the new springs / spring seats / pvc-spacers in the fork. Mark the spacers at the top of the tube, and then measure a bit down from that mark. (Preload / length of fork cap).

I understand doing that on the left side, but on the right side / Cartridge side, i need some help.
I dont know what spacer length to use on this side.
The spacer will not "hit" the bottom of the fork cap like the left side, so i guess i can not measure it on the same way ?

Is my solution : Sonic spring + pvc spacer = 18.67 in. (The specification of the OEM springs)

I am about 195 lbs. without gear. Any suggestion for left/ right spacers , oil viscosity, and oil levels ?

Best Regard
Kai
Norway

I used Works progressive springs in both of my ST1100 ABSII bike and IIRC I used about 1 3/8" spacers on both sides. It just depends on how much preload you want to have. The problem is it's a real pain to 'change' it after you get the front back together. I'm a big guy, load the bike heavy, and like a stiff front end.

Kairo said:

Removed the old springs , and discovered that only the left side having a spacer.

I understand doing that on the left side, but on the right side / Cartridge side, i need some help.
I dont know what spacer length to use on this side.
The spacer will not "hit" the bottom of the fork cap like the left side, so i guess i can not measure it on the same way ?

Click to expand...

The right side should have a spacer, but it is attached to the cartridge assembly so maybe you didn't notice it as being the spacer. At the top there should be a nut on the end of the threaded damper rod, with a washer underneath it. That washer holds the spacer in place. If you don't see any spacer, then the PO must have removed it. See attached parts diagram, the nut is 29, the washer 15, the spacer 5. You will need to compress the spring and remove the washer, it has a slot cut out of it so you just pull it away from the shaft after the spring tension is removed. Its easier if you get a helper, but can be done by one person with a little practice.

Its been a long time since I measured my spacers, and I removed the stock ones so long ago I've long forgotten their lengths, so I can't help you with that. I seem to recall the stock spacers may have been the same lengths, but not really sure about that. What I did on my bike is put a nominal length spacer in the right tube and leave it alone. I then adjust the front end stiffness by adjusting the spacer length in the left tube, which is much easier to adjust. Different springs will require different spacers though, so if the springs came with spacers start with theirs and adjust to your own taste from there.