Thanks Andy, I've googled Ceriani and I think you're spot on.

There are also plenty of threads on various forums regarding setting up Cerianis.

Here are a couple of pics. I'll also start another "does anyone recognise these...?" thread.

Cheers

What type and weight of oil would you recommend using in front forks please?

I have a C15T with non-standard front forks (I'm not sure what they are I'm afraid).

The previous owner had used 20W50 engine oil, but I feel that isn't giving sufficient damping. I used the bike on a long-distance trial at the w/e; I could feel the fork banging off the stops in extension while riding the trails between sections, so the rebound damping would appear to be insufficient.

From the dents in the mudguard caused by contact with the bottom yoke, the suspension evidently bottomed out as well, though I did take a pretty big 'hit' dropping out of a section into a gully.

I was going to replace the oil with a known weight - which is why I'm asking for advice - make sure the forks are properly bled, and then experiment with gradually increasing the oil quantity

Try NJB Shocks website He made mine for my C15 He makes them from 280 mm approx 11ins. Excellent quality

Thanks for that, I'll give them a try.

Thanks for that 'Thumper', I really should have given more detailed info about the bike.

It is 1961 and is actually a C15T engine in a B40 frame; apparently this was a favourite combination on the trials scene at the time. As both C15 and B40 are spec'd for the same rear shocks I didn't think it was significant - but I may well be wrong.

I hadn't appreciated that the extra length of the shocks currently fitted was the cause of the chain/pivot interference, but now you point it out it makes perfect sense. I'll replace with 11.9" and see if I get clearance.

I'm currently awaiting a reply from Bike Revival regarding what shocks they would recommend. I'm planning to ride the bike mainly at club days in forestry and some Long Distance Trials around Exmoor. I will be riding the LDTs for fun rather than competitively, but I'd still rather put something decent on it, not just the Emgo stuff you get on eBay.

Any recommendations would be appreciated.

My rear shocks are a bit pogo-ish so I'm after new ones.

The existing ones are 12'5", but all the info I can get (not much) points to the correct shock being 11.9". This is the length given for both the C15 and B40, but no mention mention is made of Trials. Is it the same for the T? Can anyone knowledgeable please confirm?

Also, the chain currently runs directly over/on the swing arm pivot and is wearing slight slots into it. Is this correct or should there be some manner of chain slider to protect the frame from wear?

The oil pump is a recently replaced recon item so I can't really get improvement there.

I have noticed that the level in the scavenge pipe (I have clear pipes) drops by around 5"over the course of a couple of days, so it is certainly leaking back through the scavenge side of the pump.

I'll put an NRV in the scavenge line to prevent that, but am not convinced that putting any restriction in the supply line is a great idea. I'll just buy Mrs B a replacement for the baking tray I've just nicked out of her range to park under the sump - problem solved (ish) 

Thanks for all the help & advice guys.

Trying as a PDF

That seems to work. I haven't drained the sump since identifying the leak; I'll give it a go now