At this point, I just figured that the sky was falling and ran scared for the Showa fluid.Įven now that the bike has been fixed, I'm still left wondering what exactly fork oil is. I see threads about people using ATF in their adventure bikes and swearing by it. I see threads about Goldwing riders using ATF in their forks, and saying that it's even in the manual. In todays modern race and road bikes this sophisticated range of fork oil offers optimum performance and reliability in suspension tuning. Many references to a chart from Peter Verdone, in which the Showa SS-8 is surrounded on both sides by oils that aren't 10W. Easy! But when my peanut sized brain types 'best 10w fork oil' into the internet box, I see threads discussing fairly significant sounding viscosity differences. My manual called for SS-8, which is sold as 10W. Unfortunately, I'm not sure how much I learned.Īt first, it seemed simple enough. Trying to pretend I'm a diligent consumer though, I did some reading and cross-shopping. With my rebuild, I ended up using the recommended Showa SS-8. Spent some time ordering parts, tearing down the front end, and got the forks sealed up tight. ‘cSt’ stands for CentiStokes, an accurate dynamic measure of viscosity ( ISO 3104:1994 & ASTM D445-04 ). Lost enough fork oil to soak my brake pads on the trip home, where I kept it dripping into a pan. Modern fluid viscosity ratings are on an ISO VG (visocosity grade) using test standards set down by ASTM D-2422-97 (2002) & ISO 3448:1992 system of: cSt40C / cSt100C / VI. After a nice weekend out, I noticed my fork seemed a little. I recently had some unplanned excitement, in the form of blowing out a fork seal real good.

Mtb fork oil viscosity chart