I was just comparing some Campagnolo "Gran Sport" marked bar end shifter
bodies to the unmarked ones we are all pretty familiar with and was surprised
to see they are quite different. If you look at the lever, the later lever
has a larger diameter for cable take up than the early one. I don't have an
early one to compare it to, but the late one doesn't fit the early body.
Looking at the distance from the edge of the hole for the screw head to the
edge that is adjacent to the handlebar, the older GS measures 5.8mm, the
newer GS measures 7.3mm. They obviously moved it back to increase the cable
take up. Another difference is where the lock nut goes: the late one (1955)
is relieved so a Campy T wrench can be used to tighten the nut. The early one
is not relieved, it is the same hex shape as the part 139/2, "Dado di perno".
I don't have a parts catalogue covering the earlier parts (un-numbered 1951,
1952 or 1953 catalogue #12), but I suspect the equivalent part may be longer
so the lock nut (139/1) is "proud" and not flush.
The one other "visual" difference is the angle that the body has at the rear,
it's raked noticeably forward from the bottom to the top, whereas the late
ones are more symmetrical.
So the earliest Gran Sport marked shifters had the bronze chrome plated
levers and a different geometry than the later Gran Sport (unmarked) shifters
with the alloy levers, that were modified to provide faster shifting/more
cable take up (for 6 speed?) to go along with the "new improved" Gran Sport
rear derailleur (with the 8mm spring cover) and easier adjustment with
Campagnolo tools. The illustration in Catalogue #13 (1955) shows the later
parts along with the introduction of the "T" wrench.
The first iteration was likely produced from 1951 through 1954, at most.
Was there another variation in there? Does anyone know what year the alloy
shift lever was introduced on these?
There was a bronze lever shifter on ebay just recently <
http://ebay.com/
Stevan Thomas
Alameda, CA