Mark,
This sounds just like removing a broken light bulb base from a socket, except that you do not have to turn off a circuit breaker first. I have not come up against what you have, but have had similar encounters with household hardware of the electrical and plumbed varieties. I gather from your description that there is not enough dust cap left outside of the crank arm itself to successfully grip and turn the cap with needle-nosed pliers.
There are tools made especially for removing light bulb bases from sockets, and a tool that is made for chandelier-base or normal "A" base bulbs might do the trick for you. Check at your local hardware store in the electrical department. (Lubing the threads with Liquid Wrench or similar solvents first is clearly called for. What did you use on these threads?)
There are also spring-clamp, "hog ring," and other specialty pliers at hardware stores that are designed to open outwards. (Imagine a pair of inverted-vee needle-nose pliers with prongs that face out, away from each other.) You may even be able to get a pair of properly-shaped needle-nose pliers (with curved jaws, perhaps?) to grip on opposite sides of the inner surface of the remaining portion of that dust cap. Of course, one must take care using steel tools on softer duraluminum. But you knew that already...)
Plumbing valve extractors may have the shape and size that you need, too. Dental picks or plumbing washer picks (used in pairs, in opposition against the inner threads of the dust cap) also come to mind. If you have a great local hardware store in Minneapolis like Pagano's Hardware Mart here in Alameda, you will probably find what you need.
Best of luck to you on this delicate surgery.
Jon Spangler Alameda, CA USA home of Pagano's, an island institution
On Oct 13, 2009, at 8:29 PM, <classicrendezvous-request@bikelist.org>
wrote:
>
> Message: 8
> Date: Tue, 13 Oct 2009 21:36:26 -0500
> From: Mark Stonich <mark@bikesmithdesign.com>
> Subject: [CR] Help with DA crank dust cover removal
> To: <classicrendezvous@bikelist.org>
> Message-ID: <E1MxtfZ-0001MP-Ag@elasmtp-scoter.atl.sa.earthlink.net>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
> Help!
> I bought a bike with a nearly unused 1st generation Dura-Ace
> crank. One of the aluminum dust covers was shattered, with the outer
> cover gone and just the threaded bit stuck in the crank.
>
> Any suggestions?
>
> Mark Stonich;
> BikeSmith Design & Fabrication
> 5349 Elliot Ave S. Minneapolis, Minnesota 55417 USA
> Ph. (612) 824-2372 http://bikesmithdesign.com
> http://mnhpva.org
>
Jon Spangler Writer/editor Linda Hudson Writing
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