Shifter boss compatibility

rkunkle said:

I just got an '85 Trek 1000 with one of the first Shimano
600 6spd indexed rear levers. It's busted - the teeth that
used to engage with indents in the shifter boss broke off.

Yes, this is the usual failure mode for those. Almost all of
the 6-speed 600 shift levers have failed this way by now.
That was the only model to have this particular problem.

Quoted message said:

It looks like the boss is made especially for indexed
levers, because of those indents where teeth fit, so I'm
wondering if I have to get an old Shimano indexed lever to
replace it - if I can't just get any friction shifter (I'm
fine with and appreciate friction) and make it work. There
is about half an inch of the usual cylinder with a flat on
either side, kind of an AstroDome shape, but there's no
square part at the bottom for the limiter tooth thing -
instead there's a hollow cylinder the size of the shift
lever base around the base of the boss, into which a ridge
around part of the edge of the base used to fit.

Used to be that every derailer maker had its own proprietary
braze-on, you have the Shimano type.

Subsequently, the industry has adopted the Campagnolo-type
as the de facto standard, and that's what most bikes since
the late '80s have used.

I believe that you can use any Shimano down-tube shifter on
those braze-ons, just leave off the adaptor bushing that
comes with them.

Also, the Shimano braze-on used a 4.5 mm bolt thread, vs
the 5 mm bolt used with Campagnolo/standard braze-ons, so
you'll probably need to use the mounting screws from your
old 600 levers.

Shimano down tube levers are switchable friction/index, so
even though you are very unlikely to find any 6 speed ones,
you can use 7-, 8-, 9- or 10-speed levers, offering an easy
upgrade path in the future.

Sheldon "Standardization" Brown +----------------------------------------------------------
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Upgrade path? I'll not have my birthday present maligned! I love the derailer, and I'm glad the fix is easy - 2 bucks plus 5 shipping from ebay. Do you have anything around the shop, perchance, that would be cheaper?
(That asserted, I found a Mavic track hub I'm planning to build up when I stop daydreaming, graduate and earn more than forty bucks a week. I'll sell the Trek then, but for now I like its DeLorean aesthetic.)