Cannondale Headshok salvageable?

After years of working beautifully, the headshok in my wife’s Cannondale F400 finally gave up the ghost and completely depressurised on a ride. I’ve subsequently pumped it up again and it is holding air but I suspect it will fail again when out on the trails.

It’s an old bike now (maybe 2004-ish, we bought it used so not totally sure) but the frame is really light and comfortable so she is keen to repair if possible.

Does anyone know what our options are here? I’ve found this on ebay but don’t know if it will fit:

https://www.ebay.co.uk/itm/Cannondale-Headshok-Air-Cartridge-Cylinder-Upgrade-KH005-Fatty-Ultra-DL-DLR/283859714437?hash=item42175b8185:g:ybUAAOSw-bNdj9rP

The valve plate does match the diagram with the green tick (see pics in eBay listing) but I have no idea if the headshok itself is even a DL/DLR. All I can see is that it says Ultra on the side of the fork (no mention of fatty).

I guess two initial questions:

1. How do I identify what headshok we actually have?
2. Is there anywhere in the UK still servicing these?

Thanks.

I can’t really help with where as we got some parts from Thumbprint Tuning, but I’m not sure they’re in business still.
http://www.retrobike.co.uk/forum/viewtopic.php?f=41&t=396743

Parts were often very specific with internal changes in model between years.

You can get a reducer cup from Cannondale 1.53″ to other sizes for a new fork.

They were great suspension in my view, sadly typical Cannondale in using proprietary parts and tools, designed for professional servicing only.

I think a headshock would be perfect for a gravel bike. They did make CX and ‘silk road’ touring bikes with them.

Our old F900SL was the lightest bike (by quite a way) that we’ve ever owned.

Something similar came up a couple of days ago, try a search. My input was to contact https://qwertycycles.co.uk and see if they can help (no connection to me).

Sent them an email. Thanks.

It’s a beautiful bike you ride, with a fork which it was born with. Just don’t get rid of the fork or replace it, like some do for the sake of available maintenance. .
There are many ways to repair your fork and bring it even to better-than-new condition.
You will not find lighter yet so flex-less fork anymore.

But I can’t stress it enough for guys without experience with Headshok -do not try to fix it on your own without proper tools and experienced guidance. I’ve seen a lot of attempts on YouTube, most of them totally misleading!

But I can’t stress it enough for guys without experience with Headshok -do not try to fix it on your own without proper tools and experienced guidance. I’ve seen a lot of attempts on YouTube, most of them totally misleading!

Yes, I’ve pulled one apart and you can’t re-assemble it without special tools!

Sent it off to be re-built in the end.

for the OP (a while ago), it’s likely just needing a new air seal kit.

easy enough if you have the castle tool to remove the damper cartridge. There are other ways to remove them, homemade tools, but if it’s not removed right you’ll chew it up.

I’m an old cannondale-aholic, currently with a 2003 F600 super fatty headshok as my gravel/mtb/roady bike. I too need to chage the air seal. did the cartridge when I got the bike a month or so ago, but it’s started to lose air over a week.

🙂

Lovewookie, if your air cylinder is integrated (not separated) you can’t find quad seals anymore except in the kit KF236 which is getting rare and expensive. Although there are some solutions…

nah, it’s an air cylinder separate, though I never normally bother to try to drive it out of the fork. I fear the earings will shift with the cartridge out if I start tapping on the bottom of the air cylinder, and I really could do without having to reset those as it can be a total pain. 🙂

I’ve got spare seals accumulated over the years

out of interest HSE, as you seem to be relatively new around here and have a very specialist user name. are you able to offer a service to old lefty/headshok owners?

Being new on this forum doesn’t mean I’m new with headshok… 😉
I’m here to try to help riders make better decisions with headshok forks. I’ve realized people get lost too often trying to figure out this specific fork. Not to mention what local bike shops can do to it, while thrilled rider thinks his fork is in good hands for repair. Even Cannondale couldn’t handle it. So many complains after service. If more enthusiast like me got live earlier, maybe Fatty woudn’t die.

Btw, Google makes wonders 😉

Cheers
HSE

Btw, Google makes wonders

Haha, yes.

Great that your on here and willing to advise. Most online guides ran out in the late 90’s!

Headshok forks are great. Lefty’s even more so. 🙂

Here is my Killer V Resto from another forum

Some Headshok service manuals on Sheldon Brown’s site

https://www.sheldonbrown.com/cannondale-headshok/headshok_service_manual_en.pdf

I’ve just picked up a 2006 F600 Frame with a DLR80 headshok, air pressure was low when I got it, but seems to be holding OK (roughly a week), though it’s not been ridden, so I’m sure I’ll be back on this thread 😉

It’s pretty much a bare frame & forks I got for the next winter/lockdown project. Very impressed with the weight though.

I’m pretty sure that Dave at RSF can help you. Certainly worth giving him a call.

Headshok forks are great. Lefty’s even more so.

Thanks for the inspiration Lovewookie.