Old cannondale headshok help
#1
Senior Member
Thread Starter
Old cannondale headshok help
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?
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?
#2
Senior Member
Thread Starter
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.
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.
#3
Senior Member
Thread Starter
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.
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.
#5
Senior Member
Thread Starter
I'm proud I got it into a good usable condition, especially considering was my first headshok. The new owner is happy too.
#6
Senior Member
Join Date: Feb 2016
Location: SE Wisconsin
Posts: 1,851
Bikes: Lemond '01 Maillot Jaune, Lemond '02 Victoire, Lemond '03 Poprad, Lemond '03 Wayzata DB conv(Poprad), '79 AcerMex Windsor Carrera Professional(pur new), '88 GT Tequesta(pur new), '01 Bianchi Grizzly, 1993 Trek 970 DB conv, Trek 8900 DB conv
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 759 Post(s)
Likes: 0
Liked 810 Times
in
471 Posts
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.
#7
Drip, Drip.
Join Date: Oct 2020
Location: Southern Ontario
Posts: 1,575
Bikes: Trek Verve E bike, Felt Doctrine 4 XC, Opus Horizon Apex 1
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 1034 Post(s)
Liked 193 Times
in
163 Posts
I recommend that you saved yourself the trouble in the first place and found a rigid fork for the thing
.
.
#8
Senior Member
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.
#9
Senior Member
Join Date: Jun 2005
Location: Kentucky
Posts: 2,599
Bikes: 06 Lemond Reno, 98 GT Timberline mtn.bike
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 427 Post(s)
Liked 699 Times
in
436 Posts
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
#10
Senior Member
Thread Starter
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.
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.
#11
Newbie
Join Date: Jun 2022
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Delta V500 headshok
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
#12
Senior Member
Join Date: May 2022
Location: USA - Southwest PA
Posts: 3,082
Bikes: Cannondale - Gary Fisher - Giant - Litespeed - Schwinn Paramount - Schwinn (lugged steel) - Trek OCLV
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 1397 Post(s)
Liked 1,877 Times
in
1,080 Posts
#13
Newbie
Join Date: Mar 2019
Posts: 10
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 3 Times
in
2 Posts
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
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