it is a 22.2 steel tube welded on at an angle to a clamp that grips a 22.2mm tube.. the upper portion of many seat posts..
the angle is such that it's tube is horizontal when mounted.. it is possible to have one made.
Maybe a dealer to dealer stock transfer is possible, have your people call their people... some other retail shop may have one..
By the way .. the older Mk 2 bikes were a little shorter... I had one (AW3 hub dated 94)
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Last edited by fietsbob; 03-30-18 at 09:07 AM.