[Closed] Cannondale Single Thingy Fork serive/repair

http://www.fastglass.net/bike/headshok/repair.html

A guy called Steve Lockart : aka Spannerman used to service these but he's moved on from the bike industry.

I am still in touch with Steve on Facebook and can message him if that helps.

Interested ! Was he the guy who started a pic heavy thread just before the great STW site crash ? I could never recover that thread which was excellent.
Watching this with interest

You could try asking:

https://qwertycycles.co.uk

they know a lot about Cannondales / parts / servicing.

(no connection to me)

There's also Uncle Sheldon's guide (RIP):

https://www.sheldonbrown.com/cannondale-headshok.html

Thanks - very helpful - passing info on ASAP

"Clunking" can be dangerous to internals. Your friend better stop riding it before some greater damage occurs. Dismantle-Diagnose-Repair is the very next thing you should think of when you notice "clunking".