The original Ace used the Crane derailleur. The EX was a completely new group, that was out by the year I got my first 10-speed, 1979. Readily-visable features that distinguish from it from original DA include:
Crank: recess in arm near axle bolt to increase heel clearance, self-extracting bolts (recently revived for 9-speed group, also seen in an improved form on C-record).
Ft Der: All allen fittings, no holes in cage, pebble-finish triangle on outer cage.
Rear der: Marked "Dura Ace," in big raised letters, had funny Hatch Plate mechanism to free chain from pulley cage.
Hubs: The first cassette design, availabel as 5-speed or 6-speed. Shimano's first Uniglide (twisted tooth) cogs, plastic dust caps, D-ring deleted from QR. Cogs went to 11.
Heasdet: alloy as opposed to steel of orig. DA. Funny flower-shaped "flats" on adj cup and locknut. Note that these are designed to allow use of a standard 32 mm wrench, or the proprietary Shimano tool.
Brakes: levers were slotted instead of "drilled." Caliper had very distinctive triangular bridging where rear arm extended up to the adjusting barrel. Deleted the traditional locknut/adj nut pair, for a less convenient design that required removing the caliper to adjust the centerbolt. No big deal once you figure out how to do it, but hardly Service-des-course.
Goup included an all gold Uniglide chain.
No pedal, stem or seatpost in group.
As I recall, before the AX came out, the DD cranks, areodynamic post and stem and the direction 6 hubs were available as additions to the EX.
Tom Dalton
Emmaus, PA
, It had cassette hubs that were availabe as five or six speed, a cran.
Jerome & Elizabeth Moos <jerrymoos@sbcglobal.net> wrote: I've always had a very cloudy picture of the EX group. Does anyone have photos of the complete gruppo (since it has been confirmed that it is well within the CR timeframe)? Was the EX RD the Crane that they finally got around to marking Dura Ace? What about brakes and hubs? I've seen a lot of Shimano pre-index stuff that is newer than original DA and which is not AX, but I've always been unclear as to which of it is EX and which is some other unnamed Shimano variant.
Regards,
Jerry Moos
ABB3330002@aol.com wrote: Sharp eyes, Tom! The AX design followed the EX by a couple of years. With the EX design, Shimano was feeling its way forward trying to fit the radical design ideas of the AX group into a the EX campy-copy group. The fit bulged all over. By the time the AX group was released at the New York Bicycle Show in 1980, it was totally aero and all the design ideas merged( though the actual on the road experience had to be jigged somewhat-- frames were fitted with stiffening plates in the bottom bracket extending into the rear triangle and silly ideas had to be dropped i.e. "aero" pumps faired around seat tubes<Miyata > and tiny water bottles.) All inall the AX group holds together visually on an aero frame in a way that the EX assortment never did. Alan Bernstein, the best of fall in NYC (except Bush is in town so noone can move on the roads.)
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