(If you're reading this, chris.p, you were right; I didn't need a spring compressor!)
I blame Mossleymonster for my latest expense! In his recent post
http://www.ukmonster.co.uk/monster/s...ad.php?t=56203 he was looking to fit a softer spring for his 1100S. I had thought about doing that myself, but had put the idea on the back-burner. MM's post got me thinking again.
Some time ago, I replaced the progressive Sachs shock with an Öhlins unit, which was a great improvement. It comes with a 115N/mm linear spring as standard (interestingly, the 1100S Öhlins is 130N/mm, which seems to be way over-sprung in my opinion).
Anyway, although much better than the Sachs, I still thought it was a little firm for my liking (out of the box from Öhlins, there was minimal static sag, maybe 1mm, and I had to wind back the preload a few turns to stop it topping out over bumps). Chatting with Jack at Crescent in Verwood revealed that a softer 105N/mm spring was available so I thought I'd give it a try and picked it up Wednesday.
Fitting is pretty straightforward. To remove the shock, it's necessary to support the back end; a pair of step ladders and a steel tube does the job.
The bolt for the shock's top mount can just be reached with a ring spanner without removing the tank.
With the preload rings wound right down, (this is best done while the shock is still on the bike), the c-plate holding the spring in place is loosened...
...and, with a bit of wiggling, it's removed.
You can see the generous length of preload thread once the spring is removed.
For comparison, here is the Öhlins spring next to the original Sachs unit. You can see the Sachs spring is progressively wound with the coils tighter at the bottom, while the Öhlins is linear.
The Öhlins and Sachs springs are actually almost identical, sizewise. Inner diameters are the same and the Öhlins is just 5mm longer at 170mm. So there's no reason why you couldn't run an Öhlins spring on the Sachs shock, which could be a pretty cost effective way of improving the ride without splashing out on a complete new shock.
At £75, the Öhlins spring is an affordable upgrade.
Note that there are a lot fewer preload threads on the Sachs, so I'm not sure you could release the c-plate just by backing off the preload; a spring compressor might also be needed.