How easy is it to put normal forks on to a bike that has an old headshox? Advice on what is needed and pictures would be appreciated.

reducer headset is all you need (remove the C'dale one and replace it with this), check out the FSA pig reducer headset on CRC

http://www.chainreactioncycles.com/Models.aspx?ModelID=25722

Ok that seems quite simple, now if I put modern forks on it, how can I work out what travel I can get up to with out effecting the geomertry. The frame ia an old Super V 1000

measure the current forks Axle to Crown (from the axle to just under the crown of the headset), a typical modern 100mm fork is around 480mm.
Use this figure to work out what length of fork you need, adding a couple of centimeters will remove 1 degree to the headstock (IIRC), so don't add to much to the old length.

A 1.5" to 1 1/8" reducing headset WILL NOT WORK on a Cannondale headshok frame. Headshock is actually 1.526" diameter, ie not the same as the onepointfive standard.

I did the conversion last Autumn. What you need is a set of reducing spacers. CRC sell some by Marzochi which i used and worked fine. Problem solvers also make some, and I bought a set of those from Jensen USA for the other halfs bike in preperation for the same job.

The spacers from CRC add 4mm to the length of the headtube, but also allow you to use any 1 1/8" headset.

As for travel. I ran an 80mm Headshok DL, a 110mm travel Lefty DLR, and a 140mm Magura Thor on a Caffeine frame with no drastic consequenses to handling. Head angle was about 68deg with the Thor, compared to a standard 70 with the Headshok. And your SV1000 should work better with a longer fork than my hardtail ever would have done.

A 1.5" to 1 1/8" reducing headset WILL NOT WORK on a Cannondale headshok frame. Headshock is actually 1.526" diameter, ie not the same as the onepointfive standard.

your confusing steerer tubes and headtubes

Is it easy to convert a Headshok to a Lefty? I've always fancied one and they seem to pop up every now and then.

RegP – Member

Ok that seems quite simple, now if I put modern forks on it, how can I work out what travel I can get up to with out effecting the geomertry. The frame ia an old Super V 1000

what you want to do is turn it into an Uber V

if you fit a jekyll swingarm you can have 4-6inches of travel without affecting the geometry of the frame

No Im not. The original question was to run a normal fork on a Cannondale Headshok frame. The next post suggested a 1.5" – 1 1/8" conversion headset, this I guarantee would not have worked.

Then I explained why.

Up to you whether you heed my advice or not.

Headshok to Lefty is easy. Headset and stem are both the same.

All you need is a lefty, complete with both crowns, and the little spacer that sits above the lower crown (this is important, and often missing from ebay ones).

A 1.5" to 1 1/8" reducing headset WILL NOT WORK on a Cannondale headshok frame.

Yes it will. I've fitted them to two Cannondale frames. Worked perfectly.

the little spacer that sits above the lower crown (this is important, and often missing from ebay ones).

You can use a spare stem spacer ring. I did, and again, it's worked perfectly!

I converted a Cannondale F500 last year. Had to knock out the Cannondale cups and used a hope reducer headset. Running Rockshox Recon forks now without problems. All working fine. I wouldnt recommend the pig headset. the depth of that insert is quite long due to it's downhill application. The C'dale head tube is machined internally and the FSA pig "may" not work, the Hope one is a more standard length and worked for me.

I stand by my comment, that the reducer will work, yes a lefty steerer is 1.56 and the new 1.5 std is exactly 1.5" but those are the steerers not the headstock as mentioned.
I had a "1.5 STD" fork on one of my C'dale and then changed it to a Lefty, so the headsets do fit C'dales.

oh oh and I have a spare Jekyl swinging arm (the correct one, not the bonded one) if you want to turn yours into an Uber V (lots of info on MTBR C'dale forum about em), also have a spare lefty spacer if you need one (not ready to sell my spare lefty max though)

Your headset will not be a proper fit in the headtube Im afraid as a Headshok headtube is a tiny amount bigger than onepointfive, 0.026" bigger actually. It may well work, indeed it is a small difference, you may not even notice a problem. It is not right though.

The spacer is only really relevant to Lefty fitment, completely irrelevant to normal fork instalation. The spacer is needed to make the stem line up perfectly with the top of the fork steerer when it is assembled correctly.

Billy – I'm pretty sure you are wrong.

Headshock/lefty steerers are larger than 1.5", but the outside diameter of the headset is the same.

That said however, I'm led to believe that on some older frames the cup insertion depth can be an issue unless you get a headset with a low insertion depth.
Maybe older frames also have very slightly larger headtube diameters, but I doubt it.

p.s. there also was no spacer above the lower crown of either of my leftys (even as attached to a brand new c'dale bike).

Billysan, sorry, but you're talking cobblers I'm afraid. Have you actually tried this, or are you simply going by figures and numbers? I've done this to two bikes, without any issue. And I've seen other Cannondales with this done. And Cannondale were selling at least one bike with such a reducer headset.

A reducer headset is preferable to the reducer cups, as the latter increases the stack height and restricts you to using an 80mm fork max, without messing up the geometry. I've stuck a 100mm fork on a 'Dale with an FSA reducer headset, and it's been fine. About the same axle to crown height as a Headshock.

I think to be fair, it depends on the age of the frame.

Used both reducer cups and 1.5 step down headset without drama on mine. If memory serves, Cane Creek make the Double X headset specifially for Cannondale frames (although shite headsets).