Slipping clutch
 

During my ride down to London today my clutch was slipping badly in first and sometimes second gear. Seemed ok in the higher gears. Never experienced a slipping clutch before!
The only change that I have done is changed the levers for after market ones. I can't see how this can cause this and maybe this is a coincidence.

Clutch plates were changed a couple of years ago but not done many miles in this time.

Anybody any ideas what could cause this?

Been looking back through some older posts.
I found this comment from Nelly in 2008:-

"I've lost count of the number of slipping clutches and binding brakes that have been down to patterns causing pump up's in the master cylinders. Clutch you can live with, but if the brake pumps up..... then you'll lock the wheel."

Can someone explain please what "pump up" is and why this could happen with pattern levers?

Colin, when the new levers are fitted, the pins that accuate the cylinder need to have some free play in them. Only a couple of mm, but enoughto allow the piston in the cylinder to realese the pressure. If not, everytime you pull the lever, a little pressure continues to build. basically the slave cylinder isn't allowed to return fully and this can lead to slippage.
Screw the pin in to the collar a little and see if that cures the issue. Over do it if you're not sure of the free play to prove the point, then once/if it's cured, turn it out a little to reduce the free play.

Take off the spazzos and try the bike with the standard levers - if its cured you will have to modify the spazzo or stay with the originals.

Thanks Nelly that sounds like it could very well be the problem.

Just checked now. There was no play at all. Screwed the pin in a bit and now it feels better. Will try it tomorrow night on the way to the pub.

Had a lot of grabbing probs when first bought Mutts...bought new clutch set, which was close to 38mm limit, so took out one 2mm plain, and 2 springs. Now have the best clutch ever known on an Iti, and good round town too:)

Problem was the new levers. Thanks Nelly.