Headshok techies - Custom Ti fork leg question

[AtomicAtom]

Greetings Headshok aficionados,

I recently acquired a Merlin Fat Ti Extralight. It has a 1999 Fatty Ultra on it. Since this is a special bike I wanted to add some special fork legs. I found a custom bike designer who wants to work with me to create some Ti fork legs to attach to my Headshok (Black Sheep). Only problem is this is my first Headshok and I am unaware of a few key technical aspects of it's construction.

-How is the shock assembly attached to the fork legs? Bonded? Threaded? Press fit?

-Has anyone been able to remove the legs from the shock assembly? Photos? Walk through?

-Would any of the newer Fatty models have the same shock assembly? In other words, if I had custom legs made would they survive to an upgraded model?

-Should I buy/ acquire a newer Fatty and ditch my old one before I even bother starting this project?

-Will Cannondale sell me a Headhok unit without the legs attached?

-Am I crazy? (You don't have to answer this one)

I wanted to ask this community before I attempted to take my own fork apart. As far as I know this bike has seen less than 20 rides in the last 10 years! It's a diamond in the rough, that probably needs some new seals and oil just for good measure. Thanks to anyone who can send me in the right direction. So far my asking at my LBS that deals Cannondales hasn't gotten me the answers I need yet. They are working on it and supposedly contacting their C'dale reps, but I don't know if they will just try and sell me a Lefty, which I do not want. I want Headshok with titanium fork blades. How cool would that be?


I realize this is a very specialized question. I have posted it on MTBR as well. Let me know if you can point me to someone on RetroBike that you think might be able to help.

Thanks,
Atom

 

[pete_mcc]

I always thought that the steerer tube of the forks was almost hexagonal to allow the use of strips of needle bearings down it's length so that it could slide in the shock.

There's a good breakdown here:

http://sheldonbrown.com/cannondale-headshok/index.html

Personally I wouldn't, it'll cost a fortune and not work as well as you think it should (especially with a noodly ti fork attached). Ti forks work well when they are in the form of truss forks but not so good as unicrowns.

 

[jonnyboy666]

i think you are asking for alot of trouble here, headshoks are very complicated, i used to work in a cannondale dealer who did alot of servicing.

1st things first, do not take it appart if you don't know what you are doing, if you decide to ignore that then buy all the tools first and then number and photograph every bit as you dissassemble it . . . . and then give up! seriously though headshocks are not for just anyone to take appart, meaning you need to be shown how to work on them otherwise you'll end up with a puzzle with no picture to work from.

the damper/air chamber screws in to the top section of the inside of the telescopic headtube and uses a specific tool to do that, they are about £170 iirc as a separate suspension unit, although since i left the trade more manufacturers are making them for cannondale. the fork itself looks pretty normal without the telescopic unit on it other than 4 flat edges for the bearings to slide up and down on (thus making it like an octogan when looking down on the steerer) on each flat surface is a "slat" then a bearing then another "slat" then the outer tube of the telescopic unit goes over that lot giving a sliding tube over the fork, the cartridge damper and airchamber go inside the inner steerer tube. sounds simple but it isn't.

if you are going to attemp to build this Ti fork i would suggest having a professional headshock trained mechanic strip the fork. then measure the entire thing, then build the new fork with exactly the same dimensions of steerer assembly not to mention internal threads, then have the fork reassembled by the same mechanic. if he knows what he is doing he will number certain parts to make sure they go back together in the correct order, mainly the slats as these centre one tube inside another without play but allowing smooth movement, not mixing these up is crucial.

i don't think building the fork will be too hard for the builder of your choice, they'll build something that works whether it is "fatty" style or whatever, i think the steerer tube is your problem, getting that shape and the bearing surfaces wil be hard.

hope that helps,

also, i notice you are in "NYC" i was there a few years ago and saw a merlin headshock frame hung up in Marty's reliable cycles in morristown, not the same one is it?

 

[AtomicAtom]

Thanks for all the info johnnyboy! I have already been told that the re-creation of the steerer is out of the question by the custom builder. It is too complex. That is why I asked for the technical specs on how the shock unit/ steerer tube is attached to the fork legs. Someone on mtbr said the the legs are press fit with red loctite on the the joint. I wonder how hard it would be to un press fit it? Any one ever try to remove something that was press fit? Or should I not risk damaging it and get a new shock assembly without the legs attached and send it to the custom builder?

 

[amedias]

If you were in the UK I'd send you to Tony at Thumbprint Tuning as he is our local Cannondale and Headshok service centre bod, he's been workign on them for the last 15 odd years and knows them inside out.

Going on the few I'vve had I'd echo the comments above, the steerer assembly is goignt o be the tricky bit, if it were me I would buy a knackered old fatty to use as a reference, you could possibly even remove the steerer and re-use but I'm not sure, I know some fattys had steel steerers, and some alu so they are possibly bonded to the lower legs...

Matt

 

[AtomicAtom]

Heading to my local c'dale dealer today. They supposedly have an answer from the guy AT c'dale. They had given me his direct email but he couldn't answer me directly because he doesn't deal with the public. A bit frustrating that he couldn't just answer my questions. The head mechanic at the shop supposedly knows all about headshoks but wasn't there for me to question directly the other day. Fingers crossed they can help me.

 

[AtomicAtom]

Huzzah! I braved a blizzard and rode across town to the local C'dale shop where I was able to talk to the head mechanic. He was MORE than helpful going so far as to literally hand me a set of legs with shock stanchion attached and say give this to the custom builder and it will answer all their questions. The fork he gave me had a broken shock unit and was completely stripped down to the legs and main stanchion. They can cut it up all they want and I won't have to worry about them experimenting on my fork. What luck, I'm closer to this than I realized. Perhaps I will even go to the NAHBS in Richmond, Virginia at the end of the month and talk to the Black Sheep guys directly.

 

[DM]

Result!

...and it sounds like a perfect excuse to visit the NAHBS show, too.

 

[mickey@spooky]

Dude, what? This project is going to eat a lot of paychecks.
You sir, are a pioneer.

 

[jonnyboy666]

i can just imagine, atomicatom is sat infront of his computer thinking to himself:-

naysayers!!!! yeah, damn the cost!!! i will proove you all wrong!!! :x :twisted:


that's the spirit, i bet the early pioneers of mountainbiking did something similar!