1980 BMW R100T Fork Spring Preload Questions

[pglaves]

Just curious why the additional 20cc?

The added oil volume reduces the volume of the air column above the oil. The air compresses to a higher pressure with less fork travel, which reduces dive.

 

[barryg]

This is a good thread. I've rebuilt a few airhead forks, but it's been over 20 years ago. Nice to get a refresher tutorial. Thx Guys.

 

[20774]

Just curious why the additional 20cc?

The added oil volume reduces the volume of the air column above the oil. The air compresses to a higher pressure with less fork travel, which reduces dive.

Another way to think about it is that the air acts like a spring. By reducing the air, you reduce the effect of that spring, making it stiffer.

 

[nevadaslim]

This is a good thread. I've rebuilt a few airhead forks, but it's been over 20 years ago. Nice to get a refresher tutorial. Thx Guys.

Yes, thanks to all that took time to reply! I appreciate your knowledge, and wisdom.