fork oil-tires

Not open for further replies.
Sep 8, 2007
Country flag
I have a couple more questions concerning my '73 850. What weight fork oil do you recommend and is the Avon Roadrunner universal as good as or better tire then the Dunlop K81 for this bike?

Thanks again,Larry
SAE 20 is what I use. Some riders prefer ATF but you may find the forks top out with that. I think ATF is too thin personally, but others here may disagree, this topic having cropped up a few times before, you could use the search facility to find some of those posts about it.

The New Avon Roadrider tyres are now replacing Roadrunners and do seem to be pretty good (see kommando's post about them).
I've always used ATF in all my bikes and I change it often. ATF is relatively inexpensive and its performance seems to suit my riding style.
I find fork oil SAE20 possibly too thick for my bike set-up and my weight (150lb). I have progressive front springs and the Covenant conversion and SAE20 makes my forks harsh. It seems more compliant with ATF. You have to experiment to find your own preference for your own weight and fork build.
Avon rubber compound does give good grip once it has warmed up. I have had 90/90/19 Roadrunner front and 100/90/19 Super Venom rear. The Venom gripped really well but wears quickly, then causing less roll stability as you lean into corners, since you are on the newly formed corner on the edge of the 'flat' section. This is going to be true with all makes of tyres, I suspect.
I was less convinced with the Roadrunner and found it finicky on loose dust or gravel. The 90 section front does make for very fast and responsive steering, however. No problems on clean dry tarmac or in the wet.
I am currently back on to Dunlop K81/TT100 4.10x19 front and rear. The bike handles completey differently on these tyres. It is very stable and forgiving but much heavier to turn. It neads hauling into corners instead of merely giving it a whiff of a clue. The gyroscopic efffect of the heavy 4.10 section makes big flywheels!
I suspect a size narrower on the front might make the best compromise. TT100's are tolerant of loose surfaces. Both Avon and Dunlop tramline once the rears wear flatter.
The new Avon AM26 looks interesting and others have had great results with Bridgestone BT45.
Not open for further replies.