Fork damper upgrade

I made some fork damper improvement tests.

With used stock components and 20 wt oil you can pull the damper rod up by hand in about 3 seconds.

With a new top cap and the cup flaired to .680″ you can pull up the damper rod in about 5 seconds.

With a new top cap and the cup flaired to .685″ you can pull up the damper rod in about 9 seconds.

Those are significant improvements.

The top cap should be sleeved with brass tubing as shown at:
https://jsmotorsport.com/js-motorsport-technicalmore-norton-fork-upgrades/

The brass tubing tightens the clearance at the damper rod and provides longer life.

Very good Jim.
Thanks for the enlightenment. Would you use the progressive spring instead of the stock.
Cheers,
Tom

CanukNortonNut said:

Very good Jim.
Thanks for the enlightenment. Would you use the progressive spring instead of the stock.
Cheers,
Tom

Click to expand...

I haven't used progressive springs so can't advise. But the damping mods work great.