R75/5 Fork Oil Level and Amount??

[Tom H Ca]

The Clymer and (IIRR) Chilton manuals state an amount of oil to use per leg. I bought new springs and the instructions say to do what the manual says for either quantity or level, but it has a recommendation for the oil level.

I have always used the quantity, but maybe it would be better to use the level (with springs removed) listed in the fork spring instructions???

What do you do? If you go by a level rather than quantity, what is the level you use???

Thanks you!!
Tom

[Kurt in S.A.]

Snowbum lists oil levels in this article:

https://bmwmotorcycletech.info/front-fo ... mounts.htm

Kurt

[melville]

Yes, I use 250cc per leg in my 1970s /6 and /7 forks. I don't drain and refill--if I'm replacing oil the fork came pretty completely apart.

[barryh]

Different forks but the same principle of using oil level to tune the forks should apply.

R45/R65 forks as well as having a fixed volume of 190cc also have a recommended level of 20mm - 50mm above the damper piston top. That difference allows for some tuning of the air spring effect. The 20mm level will produce the weakest air spring and 50mm the strongest. The difference between the two has a noticeable effect on the way the forks perform. 20mm for the most compliant ride and 50mm to stiffen the forks and reduce dive or somewhere in between.

I can't say I've seen a similar range of levels for other airhead forks but some variation in oil fill must be possible.

[Tom H Ca]

Thanks for the replies. I read the link, so I think I will pour in the measured amount for the drain and refill and then do the level check and see where I'm at.

Thanks again,
Tom