Can you fit a headshok fork to any other frames? Is it a 1.5″ standard sizing?

No

Yes you can, with a kit..”lefty for all”

A Lefty is not a Headshock.

Yeah, I have a normal headshok not a lefty. The trouble is that I am not sure if the frame is damaged at the seattube as there is a slight lightening in the paint work as if the tube wall has bulged out a bit. I am going to monitor it, but may have to get a new frame if it gets worse. I wondered if the 1.5″ headtubes could take a headshok, that’s all.

well i should read more thoroughly..oops

yes you can*, and no it isn’t, well not quite… **

* Some merlin frames (US Titanium Merlin) frames were built wiht headtubes that took them, and I believe there is at least one Seven frame out there too.

** the headtube itself is the same size as 1.5 inch headtubes, and 1.5 inch headsets will fit, but headshoks use a proprietary headset which is 1.56inch on the internal diameter of the bearings and it’s an interference fit on the steerer, so not like normal headsets.

You could also get a frame built with a headtube that would take one, I’m also pretty sure any 1.5 inch headtube of the correct length (this is critical due to the interference fit mentioned above, the bearing sits at specific spots on the steerer) could have the headshok/cannondale headset cups fitted as it’s the bearings that are different, not the internal diameter of the headtube itself, although from memory they might use a different cup insertion depth…

Maybe they have improved over recent years but my old headshok was horrible. I sold it on eBay though for £170 (!) and replaced it with some rebas. It transformed the bike and made me want to ride regularly again. 🙂

I’m off to pastures new where there are not many hills but plenty of rolling forests. So my Soul will be a little bit overkill and as I want to get back into XC, a cannondale with headshock will be just right for that sort of thing