Fitted Ohlins springs meant for a Honda Firestorm (41mm dia. fork leg) in my early SS forks circa 1996.
When I first put up pics of my bike with the 916 fairing in my DD diary, questions were asked about the fairing hitting the mudgaurd.
With the single rate Ohlins springs it NEVER did

You can swap the springs Alan, although springs aren't listed for it. I have a set of Ohlins monorate .85kg springs in front of me now to suit Marzochis, correct diameter etc, just a little shorter than the standard spring so the spacer tube needs increasing in length to compensate. If you think you can use them Tonio then let me know, I won't be using them now and they'll be going cheap! I boughtthem for Dessie but never fitted them.

Is that a DD rule AK?? going down the more oil/thicker route don't always work, it affects the rebound and on long bumpy sections you might start to get packing down because it takes the oil too long to flow back. I noticed both your bikes were running with about 25 -30 mm unused travel on the fork at Oulton, I didn't get any hard braking photos at the end of the straight to check to see how other bikes were set-up and didn't know whether the fork would actually go to the bottom , it may be the 25mm mark was actually full travel.

My 750SSie has a lot of fork judder (vibration) all the time under braking and changing down gears unless I set the tickover to 1800rpm or above, then its no longer a problem.

Tonio - are you 100% sure that you headbearings are tight, that the disc is true and the front spindle is straight?
I've used std Marzos and Showas and the only braking judder was when the headbearings were loose......
Also at Donny I raced with one of the forks bent by 1/4 inch...I only noticed back home when I noticed the front wheel was turning left when the yokes were straight....
How much fork travel are you using (cable tie around the slider) and have you measured your sag and preload front and rear before you start messing with the spring rates?
HTH, Paul

too late already answered, doh, must type faster :D

no not a dd rule Giz, but as scooter says its if they are the older ones you cant get the springs.

Tonio, I know I did ask you about the discs on Monday, please do get them double checked mate, as that is what would concern me 1st also check headstock too

Whilst not perfect I Ran hagon Progressive springs in my 583 some slate them but they worked well and were good enough for the fastest lap at caddy, Cost about £30 and are listed on hagons site for the early ss marzocchi forks.
glyn

Setting the sag right is definitely the first thing, start with 20-25 mm. Then knowing how much travel you actually use is critical. It may be that you have too much oil in them and the last bit of travel is "hyraulicking", i.e. the air gap is all used up too soon.

Tonio, good advice from Scooter:)