Crank Help!

Those are Williams AB77 cranks - the finest British cranks available in the 1960s:

http://www.classiclightweights.co.uk/components/williams_identification.html

You often see them installed on Moulton "S Speed" factory specials.

The bolt circle is the same as the TA 5vis/Stronglight 50.4mm, so you can fit the adapter and ring to TA Pro 5vis or Stronglight 49D cranks or a host of clones and copies. The ring is probably a 151mm bcd, which was the old track standard before 144mm took over.

In terms of splined crank history, Williams weren't the first: Gnutti were doing it in the fifties.

Good information one-eyed - I used a set of AB77s when I was racing in the late 60s. They had the advantage of being able to use the popular TA rings (either their 50.4mm 5-bolt rings or their 6-bolt rings on their adapter) or Campagnolo rings (151mm BCD in that era) using the Williams adapter that pjoseph29 has.

You're right that they were the finest British cranks of the 60s but I went back to a Stronglight 49D/TA set-up after a couple of seasons due to the design flaw in the AB77s: because of the splined axle the corresponding splines in the cranks opened up at the pointed tips.

The problem for pjoseph29 in getting a period replacement is the crank extractors. The Williams AB77 extractor (which I still have) was more or less the same as Campagnolo's. The TA (a French company) extractor of the time was 23.0mm, Stronglight's (also a French company) was 23.15mm whereas everyone else was, and still is, using 22.0mm - aren't the French great?. Stronglight extractors of that size are now quite rare and relatively expensive. VAR do an extractor tool (no. 393) which is double ended: 22.0mm and 23.0mm so TA would be an option otherwise there were some Japanese cranks produced which used the 50.4mm BCD and so would take the TA rings which achieve the right look.