[Bonked]

i'm not sure how many people are still reading either, so thought i would try both!

i purchased a fondriest off of ebay a month or so ago and would like to cut the fork, but i am having trouble removing the headset expander. the pic below shows where i am, although it was difficult to get a good shot (both pictures are of the same thing, just with different lighting). both the center and outer nuts (i'm not sure what the "outer nut" is, but had to give it a name!) spin freely, but don't seem to be loosening anything. i have also tried grabbing the whole assembly with a needle nose pliers, but it is wedged in there pretty tightly. any thoughts?

thanks a bunch!

<img src="http://gallery.consumerreview.com/webcrossing/images/fork(44).jpg">

 

[Bonked]

sorry about the double image! n/m

and you have to type at least 5 characters??? that blows.

 

[Bixe]

Expander Assembly

This is a typical expander assembly… exploded view. Assuming that your fork uses a similar type and in the situation you describe, the bottom cone is spinning with the bolt. If you can pull up on the bolt while unscrewing it, the bottom cone might seat enough in the expander assembly to allow removal of the bolt and upper cone. The lower cone will come out through the bottom of the steerer. Then with a little mechanical agitation or coersion as necessary, the remainder of the assembly will have little choice but to comply....

 

[Bonked]

thanks for your response!

from what i can see, my expander does look a lot like that one...it is good to see the whole assembly. i had thought about pulling up on the bolt, however, and it didn't seem to do much. however, now that i know what i am trying to do, i will try it again to see if i can't get it to work.

 

[divve]

Why not just slam it in deeper where it has to go anyway?

 

[Bonked]

that's an interesting thought

i guess the main thing is slamming around on a new (to me) bike with a hammer! i guess the other question then would also be how would i get it tight again as the lower piece isn't tightening or loosening anymore.

 

[divve]

Considering that I'm awaiting Fondriest I have a question of my own. I can't see any threads in the center part. Where does the top cap bolt thread in? Thanks.

 

[C-40]

no top cap bolt...

The top cap for a Fondriest/Mizuno fork is a different animal. It is tubular in shape below the top section and it's the just slightly smaller in diameter than the inside of the head tube. There are large diameter threads on the inside of the tubular portion corresponding to the large diameter threads on the plug in the steering tube. You tighten the 6mm hex in the top of the cap to adjust the headset tension. There is no top cap bolt like other designs.

 

[divve]

Is this tubular shape removable, because the stem I'm thinking of using has a closed top and uses a standard bolt? If not, is a regular carbon steerer expander compatible with the Mizuno fork?

 

[Bonked]

so, have you seen the whole thing out of the steering tube? does it look like the four piece exploded image above (i.e. would you agree that the bottom piece spinning is what is going wrong)?

thanks.

 

[divve]

I'm thinking if you don't care whether the top cap gets damaged you can do the following:

take an old stem or section of PVC pipe
slide onto steerer
tighten top cap to expander
use old stem or PVC tub as a slide hammer to knock the expander out

From what I've found by searching for the past hour you can use any carbon steerer compatible expander as a replacement in combination with a regular top cap and bolt.


(yes. it's probably spinning loose)

 

[Bixe]

While the function of most expanding units are the same, C40 is right, the Mizuno unit is a bit over the top.

The assembly on the left is out of the Mizuno/Domina fork on the P4. The right side is out of a Look HSC4, nearly indistinguishable from the FSA expander on the Domino Carbon. The problem with the unit on the P4 is that the expander consists of two long pieces rather than the four shorter pieces that the Look and FSA use. Because it doesn’t collapse as easily as the four piece units, it can be a real pain in the… uh, to remove.

Put the cap back on. Insert the 5mm allen drive through the 6mm hole in the top of the cap and unscrew the bolt while pulling up on the cap. Pulling up on the cap will seat the lower cone in the expander sections until the expander bolt is free. The Lower cone will drop out the bottom of the steerer or land on the brake bolt if it’s still in place. What’s left will be the expander segments in the steerer and how you might shake those loose…. Use your imagination. I wouldn’t be inclined to get very physical with anything inside of a carbon steerer tube though….

If the expander is stubborn, then I'd go along with Divve's inclination to use PVC coersion....

 

[Bonked]

please repost the pic!

thanks for your detailed response!

 

[C-40]

not removable

The top cap is one peice. It won't work with a stem that does not have an open top. Try Supergo for a universal expanding plug. It should work.