OK…just browsing the CRC website and Fox forks seem ridiculously cheap, some £500 off.
They have 1.5″ steerers and I wonder if anyone has ever swapped a lefty from a jekyll (or a prophet) and how easy it was. I hear good things about the fox forks and the lefty is due another service so that £90 would knock a big old chunk off a new fork.
The archive section of the Cannondale site does show the jekyll and prophet models with and without leftys so I presume its do-able?

If you change the headset and your stem as well, yes.

can you point in the direction of the headset needed?
seems to be a lot of variations of internal headtube diameter and stem diameter and cup depth.

The Cannondale headtube is 1.5″ so depending on the fork you want to buy, the best bet is to get some headset adaptors and fit a 1 1/8″ headset.
but if you want a tapered version, go to the Cane Creek website, and design your own headset.
They now sell all headset cups and the appropriate fitting kit separately.
So you can order what you need and collect it from your LBS.

Just put some F120s on my aluminium Rush that previously had a Lefty on it.

A standard 1.5″ headset will fit a Cannondale headtube. (Don’t know about integrated/ semi integrated ones.) I bought some tapered steerer F120s so got a 1.5 to taper steerer headset like this:
http://www.chainreactioncycles.com/Models.aspx?ModelID=48293

You’ll need a new stem (lefty steerers are slightly bigger than 1.5″), and at risk of stating the obvious, a new front wheel as well.

Worth mentioning that the clearance on the downtube for a normal fork crown is a bit tight as the “drop” from downtube to base of headtube isn’t as much as it is on may frames, so I’d suggest you went for a headset with as tall a lower race as you can. The NC17 I have is OK by a few mm – wouldn’t want to have much less clearance in there.

Hope that helps.

Yes definitely..

The headset came off my Gemini, a woodman Saturn 1.5 unit (huge lower race). Got the 1.5 Rev’s off eBay last year for a bargain, when the seals blew on my lefty & I was fed up with the basic damping. Have been reading a thread on MTBR saying you can plonk the new PBR/XLR dampers into any post 2005 lefty. Not a cheap option but I’ve two doing nothing, and like the lefty except for it’s damping. Though bear in mind 1.5 headset’s (or tapered) aren’t cheap either, additional ontop of the cost of a new wheel.

which for are you talking about on CRC? They have F100s and 32s heavily reduced, what out though as the F100s are tapered rather than 1.5

it’s the ones with the 1.5″ straight steerer. The headtube on the jekyll looks way wider than this.

if its definitely 1.5 steerer, you’ll need a 1.5 stem too and spacers, it can all add up quite quickly. Just to add insult to injury, if it the Fox 140mm 32 Van’s from CRC, you’ll need new brake adapter too…
I’m not trying to get you down, just trying to bring the reality of these ‘cheap’ forks.