The short lived centerpull brake calipers with matching and distinct levers preceded the much more common model B-210 sidepull caliper and M-140 brake lever in Shimano's Dura-Ace grouping and were produced for only a brief period of approximately six months during the year 1972. This is not to say that those original Dura-Ace centerpull brakes were in production throughout that same year to the extent that they had already been deleted from reference by the time Shimano published their 38 page full color catalog in December of 1972 (...and remember, lead times required for production of such a catalog in those days would imply advance knowledge of their withdrawal from market at least a month or two in advance of the actual publication date).
As far as I understand (...and I would be quick to point out that I have never been privy to the internal planning and management decisions of the Shimano corporation), in the process of creating the Dura-Ace lineup, Shimano initially "borrowed" the model B-110/B-120 Tourney centerpull caliper and M-110/M-120 brake lever (...re-badged with Dura-Ace logos) for use while they finalized production details on their new B-210 sidepull caliper and M-140 brake lever which were to supersede same. In fact, a quick comparison of the forgings used to produce the early Dura-Ace centerpull caliper and its Tourney contemporary will show the only difference between the two to be the logo marking itself.
Robert "gimme a brake" Broderick ...the "Frozen Flatlands" of South Dakota Sioux Falls, USA
-------------------------------------------------------------------------
>From: "Mike Short" <avartist@gmail.com>
>To: classicrendezvous@bikelist.org
>Subject: [CR]First Generation Shimano Dura Ace Question.
>Date: Tue, 11 Sep 2007 13:31:46 -0500
>
>Hello,
>
>I was just wondering how the center pull Dura Ace brake set fits in to the
>early generation time-line. Sheldon Brown has a copy of a 1973 Dura Ace
>catalog but the brakes are side pulls and quite clearly better finished
>than
>the center pulls. Were the center pulls 1972?
>
>Thank You,
>Mike Short,
>Austin Texas.
>
>
>_______________________________________________
_________________________________________________________________
More photos; more messages; more whatever. Windows Live Hotmail - NOW with
5GB storage.
http://imagine-windowslive.com/