Advice for converting Cdale fork headshok to Lefty

The Headshocks and Leftys use the same headset and stem type, so you're fine there.

You'll obviously need a new front wheel, with a Lefty-specific hub.

And yes, Leftys are disc-specific, so if you don't already run discs, you'll need to, at least at the front. If you're coming from V-brakes, you can simply buy a mechanical disc caliper and rotor for the front wheel, and use your existing V-brake lever.

There are a number of Lefty variants about, some of them are longer travel which will play havoc with an XC race type frame geometry, and over-stress the frame. There's a tech document about this here:

http://www.cannondale.com/Asset/iu_files/tech_center/117706_Maximum_Fork_Length_EN.pdf

With all that in mind, it's all straightforward. Remove fork A from frame, install fork B. Done. The 'tech' section of Cannondale's web site has manuals and tech notes about things that may be useful.

I did a similar thing with a 2001 Cannondale hardtail I had (moved from 80mm Super Fatty to a 100mm Lefty ELO). I found the Lefty much plusher and in general a lot nicer than the Fatty. Enjoy! 🙂

The only limit to it being "worth it" is how much you pay for the Lefty. The Cannondale hardtail frames are excellent, despite later moving onto a Scalpel I really, really shouldn't have sold mine...