fork oil or sae 10-20 oil ?

mark1122 wrote: i would just use 20 fork oil. the damping in these old forks is almost none existant.

+1

These suspensions, and service manual recommendations, are prehistoric compared to todays standards. Its going to take alot more than oil to get these suspensions to perform. Im going to install the Race Tech emulators to get some sort of dampening in my suspenders.

30w synthetic motor oil

wireman wrote: 30w synthetic motor oil

Is still lighter than 20W fork oil. Make sure that it is straight weight and non detergent.

mark1122 wrote: i would just use 20 fork oil. the damping in these old forks is almost none existant.

On my 79 750 twin if I were to use 20w fork oil then I'd save money just by welding the forks solid, wouldn't be much difference in ride. I weigh near 250 lbs and changed from 50% 15W/50% 10w to straight 10w because every little crack in the road was making the front end jump. It was like the forks were almost solid. Progressive springs with 10w oil and I'm not getting beat up any longer, suspension actually works.

My 750 twin factory manual calls out 15W fork oil. That's what I am currently using and it seems right for me. I only weigh 175 and our operating temp range around here is from about 60F to 90F, so 15W works well. I tried 10W and it was a little too mushy for me.