The air valve on my wife’s Fatty Ultra DL fork snapped off yesterday when I went to add some air. Totally corroded and managed to let all the air out when it snapped…so is it a case of a new air cartridge? How much is that likely to set me back? Does the whole fork need to come apart to replace, ie meaning a visit to a cannondale dealer with associated cost? Or is it game over and best to whip them out and replace with a standard 1 1/8 steerer fork from the back of the garage using adaptors?

On the fatty I took apart, the actual spring/damper was separate to the fork/slider/steerer. I managed to do it with some bodged tools (the castle tool was the most complex bit IIRC). The main thing is to avoid separating the fork/rollers/steerer as that’s a pain to get back together.

FWIW, I’d be looking at drilling out the broken valve and getting a replacement to fit but I like bodging/fixing.

Part number KF237 is what you need. Sits at the bottom of the fork. Held in by a circlip so you shouldn’t need to take the damper cartridge out.

I knew I had a diagram somewhere

Legend thanks! Surely to get to it though I’ll need to remove fork from bike and remove the internals with the castle tool…no?

Don’t reckon so, I think that’s why the parts are sitting under the fork crown in the diagram.

Circlip out, and needle nose pliers to pull the old one out. Push new one in with shock pump attached (so that you can pump the new valve down into place using air pressure after you’ve fitted the new circlip)and fit circlip, job done.

Right cheers I’ll have a look and see. I don’t recall seeing a circlip but it might be buried under muck!

depends on age.

newer ones you can remove it without taking the cartridge out, older ones (around 10 year old at a guess) you’ll need to get a slightly different part and you’ll need to remove the cartridge, if it will come out. If it doesn’t want to come out with the damper you’ll need to tap it out with a drift, but bear in mind it may be quite stuck, then it’s off to thumbprint….

Hmm its a 2002 model F900 SL, Fatty Ultra DL. Its been too sodding wet to venture to the garage to check it out but thanks for your help all

John, part still sitting on my desk – but call anyhow, Murray can sort you 🙂