Norton Roadholder forks are fitted to Domi’s, Singles, Commando’s and also to several 1964 onwards AJS & Matchless models.
This is a very good design and when in good condition give excellent performance. One of the biggest complaints is that they lose damping performance, as evidenced by the “clunk” at full extension.
There are several internal devices on the market to improve the performance of these forks however the damping problem is usually caused by wear in the alloy damper caps (Part No 06-1347). The damper rod passes through this cap and the rod to cap clearance should be .002″ approx. These caps do wear and clearance of .020 – .030″ is common, providing very little restriction to the flow of oil, which controls the dampening.
Mike's British Motorcycle Thoughts 