Dwillems26

Got a 1993 or 94 Cannondale Delta v700 with a headshok. The bike was in decent shape, worthy of fixing, but the headshok was seized. If I can't fix this on the cheap the bike isn't worth it anymore.

I got the shock dismantled, except for the spring. It seems to me there's a plastic cup on top of the spring that's stuck in the tube. It won't budge in either direction. The very bottom cap will press upwards and spring back so i assume the spring is good. I just have to get it out... anyone have any good tips?

Dwillems26

It is an EDM, or MC50. One of the first and early versions. There's supposed to be an MCU damper (some sort of plastic/rubber. It's disintegrated. So I'm assuming that stuff along with the grease and water clogged everything up. I've had penetrating fluid soaking for a while now with no luck. I might try WD-40 or mineral spirits or some other solvent too. At this point I'm calling it a loss, so I won't be mad if I make it worse, but I'm trying to not go full on FUBAR just yet.

Just brainstorming here...

IF I can find a replacement piece, I don't mind breaking it up to get it out, but that's a big IF.

Drill through the bottom cap, insert long dowel, and try to tap it out. Then just braze on aluminum to fill the bottom cap.

Heat steering tube slowly trying to expand the tube and loosen up corrosion inside. Trying to not melt the spring cap/plunger.

Dwillems26

If anyone is following along, here's the update.

Nothing really was working, so I ended up drilling through the bottom cap. Then was able to pull the bottom cap out along with the MCU buffer/damper that sits inside the spring. Low and behold, there is no spring. Someone along the way stole it probably for their own bike since these are hard to find.

Once the spring was out I was able to knock the spring preload piston out from the bottom.

If I can find a spring I'm sure I can clean the rest up and put it back together, I'll just leave all of the bumpers and dampers out.

mzungu54

It's designed like that. Mine don't have a coil spring either. Just the urethane spring.

Dwillems26

I appreciate that. I finally realized that it didn't have a spring at some point. Replaced it with a blue spring and bumper and it works pretty well. Had to give it a good preload though. My interior wall was pitted like crazy (where the bearings didn't run, but it interfered still), but with a lot of effort I got it smooth at least enough for the headshok to ride smooth.

I'm proud I got it into a good usable condition, especially considering was my first headshok. The new owner is happy too.

fishboat

I'm guessing, as a result of this fix, you've spent a fair amount of time looking into options to keep a headshok working. Has Cannondale and/or aftermarket parts folks walked away from headshoks? Are there any parts available? I see some very nice looking bikes pop up on CL now and then for very decent prices, but I always steer away due to the unknowns of a headshok. I haven't take the time to scour the web for repair options. Are there documented work-arounds for the lack of parts? ..lots of questions..thx.

Moisture

I recommend that you saved yourself the trouble in the first place and found a rigid fork for the thing
.

TiHabanero

Two years ago a friend of mine asked me to rebuild the Headshok on his 1995 f400. Told him not to bother as rebuild parts are not available from Cdale. He talked with another friend of his that told him to go to a certain bike shop and they will rebuild it. They did so using automotive seals. It worked for about 6 months and the seals failed. He now just rides it in the collapsed position. Smart move. Surprisingly, my F500 from 1995 with the Headshok was still working when I sold it this summer.

freeranger

Wonder if an elastomer, such as used for a thudbuster seatpost, could be modified to work (I have no idea of the dimensions needed): cane creek thudbuster elastomer - Bing

Dwillems26

My hardest part was that there's not a lot of documentation or how to's to rebuild these shocks. I was able to find parts fairly easily except for 1. Mine was the old version that had just elastomer, no spring, and they don't make that anymore. I found new old stock, but that was ridiculously expensive so I replaced it with the newer version spring/ elastomer combo. Luckily everything else worked fine. The latest version (after 94 if I remember) uses air pressure and those are prone to failure, you'll be fixing that one more often than riding it. The parts can get expensive too. I think my spring wasn't bad ($40), but bearings are $60+. I just took my bearing apart and cleaned it up, didn't have any pitting it was just dirty.

I recommend not bothering with the headshok unless you find a really good deal or just have some sort of personal value for it. This bike was given to me for free so I enjoyed the challenge, but i don't think I'll be buying one.

Chasemon42

Hi guys just curious about possibly rebuilding this headshok. I believe the delta 500 has the simplest least advanced of the headshoks. Atm it's just a bit on the soft side. Any tips a plus. Thanks

t2p

https://vintagecannondale.com/info/headshok/

https://headshokexpert.com/people-as...e-same-things/


https://www.sheldonbrown.com/cannondale-headshok.html


HeadShok maintenance / service :

https://www.mendoncyclesmith.com


.

cycology

Yes, old thread but fyi, just did mine, same 3 elastomers .suspensionforkparts dot net has top elastomers, only $9. Before I knew that I got the spring/elastomer bottom, for $30, performancebikes (remember them? )
My bearings were OK, a pain to get them back in OK. Needle nose pliers for inner top, happened to have park pin tool for old bottom bracket