Fork Fluid

[Jim Fontana]

I have a 1988 R100 RT with (gasp) Showa forks. Does anybody have recomendations on using automatic transmission fluid instead of the 7.5 wt fork oil?

[jdiaz]

I had a DRZ400 dirt bike for a few years, and the fork fluid that the local suspension tuner SWORE by was Mobil 1 synthetic ATF. It seems like ATF would act the way you would want it to....lighter when cold, heavier when hot, to keep damping relatively consistent, but I had never seen it recommended anywhere until I started riding dirt bikes.

Also, I don't think the R100RT ever came with Showa forks. I thought they used the same pieces as the K bike, and the K's were still getting Sachs forks back then. I thought the first K's didn't get Showa until 1990-ish.

[flash412]

I have a 1988 R100 RT with (gasp) Showa forks. Does anybody have recomendations on using automatic transmission fluid instead of the 7.5 wt fork oil?10 wt. fork oil works LOTS better than 7.5 wt or ATF. I use 10 wt in the Showa forks on my F650. I used to use it in all of the twenty-some airheads that I owned (except the ones with Earles forks).