Ohlins Rear Shock spring rate recommendations?

[slabsideB12Kent]

I've been working on my Slabside GSXR1200's rear suspension today. Ended up taking the whole rear end to pieces to gain proper access to the shock (1200 Bandit loom is placed in that area).

I was very happy afew months ago when I saw an Ohlins shock for sale on Eblag. Today I went to fit it and now i'm unsure if whether I should swap the springs or not as I dont want to do this job again anytime soon. 

I just wonder if anyone knows how to decode the spring rates on an Ohlins shock? I have two springs one is labelled 01091 21/75 and the other is labelled 01091 34/100. And if anyone has experience which spring rate suits a 750 Slabside with an 1100/1200+++ motor it it. 

Done some Googling and it seems 01091 is the spring design

                                       12/75 and 34/100 is the spring rate

I probably weigh 125kg's/20 stone with all my clobber on but I am quite used to the soft handling of a 1200 Bandit. 

[dupersunc]

Go to the race tech website. Theres a tool on there to calculate the spring rate.

[slabsideB12Kent]

I've spent hours looking online and I'm settling with the 21/75 spring. I used this website https://j-techsuspension.co.uk/pages/spring-calculator to calculate the spring rate needed using a rider weight of 15 stone, rear wheel travel of 5 inches and a shock stroke of 2.4 inches to calculate a spring rate of 440 lbs/in. I found an Ohlins spring decoder which I've attached which says the 21/75 spring suits a 428 lb/in, so that's close enough. The 34/100 spring has a rate 571 lbs/in which equates to about 25kgs of clobber so if the bikes soft I know what to do. Not too bothered about the suspension being soft at the rear because it's what I'm used too and the forks are running standard springs.

[Nik]

That J-Tech site's spring calculator is generic. The one on Race Tech's site is model specific. For a slabby 1100 and your weight, they recommend 100 N/mm. 

Older Japanese bikes are typically designed for a 70 kg driver, and for a full-grown man, I'd say that 75 N/mm is too soft.