For sale is a used but good condition (a couple of fiiting marks but unused by me). Replaced with a titanium sping 21040-39/110 ... 225 - 250 lbs rider weight apparently Looking for £25 posted.
https://www.youtube.com/watch?v=NJysZQv7MKg Its an RCS Spring. I found by chance new and boxed. Not sure if they make them anymore. Cost me £68 but worth a lot more. The Ohlins spring weighed 999 grams and the Titanium spring weighs 639 grams.
Didn't even know you could get a Ti spring Bloody hell Si make sure you tie that blade down mate, I will blow away in the wind soon!
Titanium Springs 57mm Internal Diameter, 150mm Free Length by Reactive Suspension - Motorcycle Suspension specialists These guys do them