Downtube gear shifters boses identification

[predki]

I have these on my 50's Holdsworth (as the frame is made in 1951/52 it has some modification done later - like the mentioned bosses, horizontal dropouts, bottom bracket cable guides and brake cable top tube stops):

I tried to fit standard Campagnolo shifters but the fixing bolt is too big and the shape of the base is quite different. I tried to fit smaller bolt and it didn't engaged the thread, just slipped past.

They are placed quite high on the downtube:

So what it could have been made for? Is it for very modern STI? Modifications seems to be done in 70's

Brake cable stops:

Bottom bracket guides:

Dropouts:

 

[Ian Raleigh]

The bosses could well be for bar end shifters.

 

[Ian Raleigh]

You looked on the classic Lightweights site ?

http://www.classiclightweights.co.uk/readers_bikes.html

 

[predki]

Re:

Yes, it could be, but on older bikes I've seen stops on clamps only. Were there any braze on types?

 

[Ian Raleigh]

I'm wondering if they are gear lever bosses which had a P shaped gear lever screwed on to them!

 

[predki]

Re:

I'm wondering if they are gear lever bosses which had a P shaped gear lever screwed on to them!

You mean this very old 50's kind? Like this one:

but usually they were for rear only and there are both on my frame.

I'm going now through classiclightweights and velobase...

 

[Ian Raleigh]

Yeh like those! I'm liking this thread so much as its so different from your everyday easy to answer posts!

 

[predki]

Re:

This kind of levers usually were used for rear derailleurs and front was rod operated and I have two for front and rear. Who would made modernization of the frame (like vertical Campagnolo dropouts) and fit bosses for so "ancient" shifters... The shape seems to be Campagnolo, but the Campagnolo washer with rectangularish hole won't fit it's a little bit too tight.

And the hole is definitely too small for the bolt.

 

[Midlife]

Some of the early Simplex downtube shifter levers had a sort of "nipple" on the inside of the lever itself which limited travel.........if you have a look at the brazed on boss it has a guide at the top with stops on the end to engage the projection on the gear lever. (if that makes sense)

Mind you they do seem pretty far up the frame.

Shaun