probably way off topic but it will help my sanity. I bought a pile of stock recently amongst which was some kind of tool. The guy told me was a Campag one for removing thingies. he couldn't recall the name of the thingies. I said "do not worry I will work it out". Ha, famous last words.
Ok, a two piece tool. One male tread fits inside a flat knurled wheel with a female thread inside. The wheel is 30mm diameter, with knurls around it circumference. The centre threaded hole is 12mm.
The piece that threads in to it is a hole bolt. It is machine on its inside to take a 6mm Allen key. It is threaded at one, this threads in to the wheel. The other end widens out to a section with six machined faces on it, which taper slightly getting wider as you move away from the threaded end, 15mm across opposite faces. The opposite end to the threads has a flange with an overall diameter of 21mm. From the flange ends, three slots have been cut in to the bolt, along the axis of the centre hole. These slots will allow the six flat faces to compress slightly, fitting into a hex slot like a 15mm allen key. The six faces taper out slightly toward the flange so they would wedge in. The knurled wheel would allow you to pull these faces in.
It is obviously for gripping a 15mm socket and turning it with the 6mm key, but where on bicycle would you need to do this?
Regards
Martin Coopland