This is how I set up my Ohlins units. I recently fitted a pair that I had refurbished by Clarence Bell the Irish Ohlins importer they are a vast improvement on the standard shocks for the 1150gs.
If you want to set up the Ohlins units on your bike set the static and loaded sag for your units so the springs compress about the same distance when you sit on the bike by adjusting spring pre load.... then adjust the damping
For conventional sports bikes with around 120mm suspension Ohlins recons on about 10-20mm static sag rear and 15-30mm front.
Because the GS has long travel suspension (200mm rear) (190mm front) I set sag at 25mm rear and 35 mm front (just the weight of the bike on the suspension). With me sat on the bike WT 80KGs this give 68mm of sag at each end (about 1 third of the suspension travel) IF you get much more than this i.e. using up more than half the suspension travel you need heavier springs less than 1 quarter means that you need lighter springs. Set this with the damping wound right off.
Most suspension folk say getting the right sag is the most important suspension adjustment.
For me most factory damping settings for Ohlins units are a bit over damped. On the 1150gs its 18 clicks out from fully front and 12 out from fully in rear. If you want you can try the damping fully on and off to see what the effects are (don't fall off)
For me I adjusted the rear suspension first, then the front and then both together starting with the ohlins standard settings I always did it this way on my sports bikes.
This is best done on new scrubbed tyres set at the correct pressure(especially on a sports bike). The GS is less tyre sensitive but there is no point in trying to set suspension up on a squared off rear or shouldered front. Go for a 15-20 minute ride to warm up the tyres and shock.
Find the fastest bumpiest bend you normally go round and ride through it. Was the ride choppy? wallowy? did the bike feel like it was sitting down through the corner? I like the ride to be as soft as possible while remaining taut. So I back off the the rear rebound damping a couple of clicks at a time until the rear of the bike begins to wallow coming out of the bumpy bend under power I then add two to three clicks of rebound then try again. If alls fine leave it. The front of the GS is odd!! On a sports bike I'd adjust the front by braking into a slower bumpy bend and see how fast it rebounded off the brakes and compressed on them and if there was any chatter. This does not work on the gs because of the anti dive telelever.
So a judgement has to be made between the damping overwhelming the spring and pumping down the shock braking on a bumpy surface before turning in and having the feeling that the front is flapping about and bouncing off the bumps. (running the bike with damping full on and off will give you a feel for this)
I like it to feel controlled plush and stable so when it felt like this for me thats how I left it.
Finally I check how both ends are working together. On a conventional bike the easiest way to do this initially is to bounce the bike up and down by applying weight to the saddle and quickly removing it (a big tall heavy bloke is handy for this!!) If the damping is resonably even the front and rear of the bike will rise at the same rate.
In addition, and for the GS which is hard to bounce in this way. I ride along a road with a few humps and hollows in it at a reasonable pace (without taking off) now I look for the feeling of the bike pitching forward or sitting down as the humps and hollows are negotiated. If all is well I leave it be if not, slightly firm up the damping on the soft end which might compromise other settings a bit. I ended up with 16 clicks out from fully in on the rear and 21 from fully in on the front. Magic carpet compared to the old suspension.
All this takes longer to explain than do and all suspension setups are a compromise. The gs isn't that difficult to set up there is only preload and rebound damping to adjust.
