Please help with reusing a 1992 Cannondale DeltaV frame

[bikesandwatches]

I've been recently given a stripped down hardtail Cannondale frame. The serial says it is from 4-1992 so it is probably a Delta V 900, its suspended fork has been gutted and if I'm not mistaken, it was not serviceable anyway... I find the frame very nice and well made, I think it would be a shame to throw it in the trash pile.



I have a friend who's knowledgeable about older MTBs, but knows little about suspended forks. I've spend a few hours on the internet trying to find a way to mount a fork, but I've read conflicting things and did not find definitive answer.

My frame has the older headshok tube : the bottom cup is bigger that the top one. Somebody documented this : http://community.vintagecannondale.com/ ... lease.193/



Finding a good, working original headshok fork appears unrealistic.

1) I obviously need some kind of reducer cups or headset to be able to use a more standard fork (1 1/. Is it possible to find one that fits in this older headshok mount?

This one is often given as example : https://www.treefortbikes.com/Problem-S ... k-Headtube . Not sure how / if it would fit the bottom cup.

Same question with the FSA reducer headset...


2) A regular skinny fork like the Kona P2 may look strange with the frame and it may be easier/look better to find a short travel vintage suspended fork, I don't want to mess the frame geometry. Any idea about a model that may fit, and be serviceable? I do mostly asphalt or light trails with slicks, so I don't need a heavily reinforced fork.

Max fork length including the adapter should be 500mm.

3) the rear hanger would be an A239x?



Thank you for any input!

 

[focomat 1c]

Re:

Why not continue to use your existing forks with the headshok ' mechanism ' locked up solid ?

The bike would look original even though the suspension would not work

You just need to source some new top and bottom bearings ( almost certainly
imperial sizes ) as mentioned in your link

 

[bikesandwatches]

It is missing all the parts inside (spring, spacers, bearings, etc) so it wiggles inside the column, it is only threaded into the top cap without being guided by the bearing strips. I also can't lock the piston (or I have missed something). I really think this fork is a paperweight, I wouldn't try it on the road as it is...

I spent a day looking at SHIS specifications and diagrams, and ordered 20eur worth of FSA headset that might solve most of my problems (a standard headset might just fit inside those oversized cups). Time will tell. I wonder how it could look with a classic fork like a Rockshox or a Marzocchi.

Nice handle btw, I have a focomat 1a on my desk, I really should find some time to use it.

 

[1978]

Re:

After many replacement cartridges and long waits from the bike shop in the early 90s, I fitted a pair of Rock Shox Judy DH to my Cannondale Delta V, which had the same fork and headset set up as yours.

I bought a set of reducers which pressed into the frame in place of the standard cups and allowed a standard 1 1/8” headset to be fitted. The top one was flat and the lower one was extended so that the geometry wasn’t affected.

I’ll do some internet research and see if I can work out who made them!

 

[bikesandwatches]

Thanks, that is interesting!

I'm waiting for a FSA orbit Z that may fit into the existing cups, I'll report if it fits.

https://shop.fullspeedahead.com/en/type ... bit-z-4334

 

[1978]

I don’t think these were the ones I used (it was in 1993) but these are effectively the same thing.

https://www.treefortbikes.com/Problem-S ... k-Headtube

Correct me if I’m wrong, but the FSA headset in the link looks to be for a standard 1 1/8” head tube?

 

[bikesandwatches]

Re:

I don't pretend to have understood all the things I need to know, but this headset should press into a 44mm internal diameter headtube, so it should fit?

I'll probably find a set of adapters to be on the safe side, but a Q&A on the page says:

Q.
My Delta V has a wider bottom cup for the old Delta V headshok. Is there a reducer?
A.
If the bottom cup is wider than the Cannondale 1.5" you are most likely not going to find a non-custom reducer to work with your frame.

But the internal diameter being the same it should be OK.

 

[1978]

Re:

There is lots of information here:

https://www.cannondaleanswers.com/defin ... ain-bikes/

You may have already seen it, but your frame doesn’t have a 44mm internal diameter head tube, it should be 49.6mm. Quoting from the website:

Cannondale Headshok 1.5″ Head Tube

Going back to the early years of Headshok and Lefty, Cannondale standardized the head tubes on their mountain bikes that would use their proprietary forks. The actual internal diameter is 49.6mm. Long ahead of their time, 1.5″ head tubes were standard. Bicycles that came with a non-Headshok fork (Fox, Rock Shox, Manitou, Marzocchi, RST, etc) would use some type of 1.5″ reducer headset for use with the typical 1 1/8″ steerer and in more recent times going straight to a fork with with a 1.5″ straight steerer. Tapered forks can also be used on Cannondale 1.5″ head tubes with the right headset or combination of headsets.

Cannondale used a press in style headset, the QHDST/EBO, which takes a 1.5″ style head tube to the 1 9/16″ (or 1.56″) needed for Lefty and Headshok forks. These head tubes measure 114.3mm (4.5″) without cups installed. The Cannondale QHDST/EBO headset installed (without upper bearing seal) measures 134.6mm.

If you have the QHDST/EBO headset installed in your frame and wish to use another type of fork, you can replace just the bearings with one of Cannondale’s reducer headsets talked about on the SI Integrated Head Tube (Standard Height).

The FSA headset that they suggest for this purpose is not the one you linked to, but this one:

https://www.cannondaleexperts.com/FSA-O ... _3116.html

 

[James986]

Re:

I’m not sure if I can be of help - I’m just in the process of rebuilding a Cannondale M600 from 92. The bottom race crown on my fork was cracked, I picked up a brand new XT quill headset on the below link. My forks were just standard rigid forks, however I know the sizes of the cannondale headsets of this period were slightly odd. The headset fitted perfectly for me if your thinking of fitting rigid forks with a quill stem this headset may fit. Some carful measuring is just required.

https://rover.ebay.com/rover/0/0/0?mpre ... 3512125075

 

[1978]

Re:

Hi James, the frames that were fitted with headshok forks like the one in question here, had a bigger diameter head tube to accommodate the shock unit inside. Yours probably has a Pepperoni fork with an 1 1/4 steerer, great find on the new headset.