Mavic compact (94mm bcd) chainrings

[one-eyed_jim]

Just in case there's any confusion about the bolt circles used, the 631 was a 130mm bcd for the main spider, and 74mm for the triple adapter, so the 94mm bcd ring can't be intended as a granny ring for a 631 triple.

I did wonder if it might be from a 635 triple:

http://www.equusbicycle.com/bike/mavic/index.html

The main bcd of the 630/635 was 144mm, which takes a minimum 41t ring. Mavic list rings for the triple from 32t in one-tooth increments, so 94mm would be a plausible bolt circle. On the other hand, the bolt hole size, and the shape of the tab would seem to rule that out.

 

[one-eyed_jim]

So it seems my last guess was correct. MAVIC 635 triples used a 94mm bcd granny ring:

http://cgi.ebay.co.uk/270762462006

The catalogue shows the granny ring with rounded tabs, but they obviously went into production with a square tab, like the rings I bought.