Informative Link Regarding Fork Oil

[Ratchet_72]

http://www.peterverdonedesigns.com/lowspeed.htm

Worth a look guys. A member on another motorcycle site pointed me in this direction

[Mark Olson]

wow that link has a lot of chedder.

[markmartin]

OK, an oil thread,--I'll bite.  Yes - Alot of chedder - most of it over my head, however I did find the info on VI with reference to changes in viscosity over temperature ranges interesting. When I re built my front forks and installed cartridge emulators, you can imagine I was a little anxious to try them out when the job was finished. Well, it was 31*F outside, spitting snow, but the roads were clear and dry so away I went for a quick 5 mile loop.  I was expecting a new plush ride, and imagining myself smirking while the front end soaked up all the seasonal frost heaves.  I was disconcerted when I experienced a really firm ride--not harsh, but, well kinda 'springy'--too much damping in my amateur opinion.  After wringing my hands for an hour and considering changing oil viscosity, preload, emulator setting etc. , the concept of molasses in January occurred to me. Now riding at normal outdoor temps the forks work like I'd expect---  a very noticeable difference.  This is with Klotz 15w synthetic fork oil which has a  VI of 400, which according to the article is supposed to have a very stable viscosity through temperature ranges.  Christ, now I'm gonna sound like an oil snob, but if I can tell the difference when using one of the better oils, I  wouldn't want a to go to a cheaper or lower VI oil.