Mavic compact (94mm bcd) chainrings

[one-eyed_jim]

I've just got back from a day at the cycle jumble with a good stack of chainrings - mostly Mavic and TA, and mostly in road-appropriate sizes. But there are one or two exceptions.

I bought two 40t rings thinking (sleepless night) that they were Mavic's oddball big 74mm bcd granny rings - like this 38t example:

Getting home and having a closer look at them, it turns out they're actually 94mm bcd. I've never seen a 94/58 Mavic crank, and I don't think Mavic were ever big in the aftermarket chainring business, so what accounts for this oddity?

If I'd known, I'd have had the whole stack (at 2€ a pop). I think they're the prettiest chainrings I've ever seen.

 

[one-eyed_jim]

Another interesting thing. While the bolt circle is 94mm, the metal of the chainring tab extends about 0.5 mm further inward from the bolt hole than on other rings (Sugino, Shimano, TA, Race Face) meaning that they won't fit most Compact Drive cranks. It may be that they missed a final machining operation to trim the tabs to size, or it may be that Mavic had their own crank to fit these rings. If so, I've never seen one, but BikePro mentions that:

Mavic USA is waiting for the French engineering group to come
up with something startling and new, which will probably have a
58mm/94mm bolt pattern.

http://www.bikepro.com/products/cranks/mavic.html

 

[cchris2lou]

yes , i would have though that mavic had stopped making rings and cranks before compact appeared on the market .

 

[one-eyed_jim]

Here they are. Pretty, eh?

 

[cchris2lou]

weird as Mavic MTB rings were black .

 

[one-eyed_jim]

Not all of them. I've got a new-in-box 637 chainset with silver rings, and I'm pretty sure the Bridgestone MB-Zips I've seen with OEM Mavic cranks had silver rings too.

Here you go:

http://www.firstflightbikes.com/1991_Br ... ne_MB0.htm

http://4.bp.blogspot.com/_yMWpZFzpA8s/S ... CN4410.JPG

http://yoeddy.blogspot.com/2009/05/pers ... -mb-0.html

 

[one-eyed_jim]

Here's a footnote.

Tidying up an old hard drive, I found this picture I must have saved from the St John Street Cycles website.

So I shouldn't have been surprised to discover that Mavic had made 94mm pcd chainrings: I'd seen one already.

 

[pete_mcc]

EDIT: Just reread your post and realised that the 38T at the top isn't yours, d'oh! I've amended my post accordingly!

were these used on a 631 road chainset with the 'triple-izer' middle ring that converts from dual to triple:

 

[one-eyed_jim]

EDIT: Just reread your post and realised that the 38T at the top isn't yours, d'oh!

I borrowed the picture, but I've got a couple of those rings somewhere too.

were these used on a 631 road chainset with the 'triple-izer' middle ring that converts from dual to triple:

Yep, except that the Mavic triple-izer wasn't incorporated into the middle ring. It was a separate spider that replaces the spacers between the two outer rings.

http://velobase.com/ViewSingleComponent ... aa38991e6a

I still don't know why Mavic made their granny rings in such outlandish sizes. Tandem timing rings for use without a crossover drive?

 

[dbmtb]

were these used on a 631 road chainset with the 'triple-izer' middle ring that converts from dual to triple:

Is also pretty much what I was going to put forward as a qualified guess.