It's 6mm and the original came with a piece of steel tube about 5in long to put over the short end of the allen wrench to act as a cheater.
Steve Leitgen La Crosse, WI
On May 16, 2006, at 7:38 PM, John Jorgensen wrote:
> Don-
>
> The angled back cap is just a protective cover for the internal
> cavity. You need a long allen key, 6 or 7mm, I forget at the
> moment, a "T" handle type works well and the fasteners you need to
> access are buried in the tunnels, Undo the quill bolt as one always
> would and tap with a mallet if required. All this trickery was to
> provide
> an aero look and save weight. Pino Morrioni did his quill bolt the
> same basic way, just he did not bother with the hidden bar fixing
> bolt.
>
> John Jorgensen
> departing from Torrance Ca USA