Clamp on downtube shifter bosses?

[otherself]

Do they even exist??? I'm seriously considering buying a Planet X Kaffenback frame as a winter road bike, cyclo cross and light tourer. The Kaffenback doesn't have bosses for downtube shifters, and -- due to funds -- I wouldn't be able to afford expensive STI or Ergo levers. However, I have a few sets of downtube shifters and I was wondering if I could some how fit them onto the downtube with some kind of clamp that has the bosses. Like 70's road bikes had band-on downtube bosses.

I know you can get "Pauls Thumbies" for donwtube shifters that mount on the handlebar n' all, but they're expensive too (£45 - 50).

 

[tee-one]

how come you cant use some from a 70s roadbike?

 

[otherself]

how come you cant use some from a 70s roadbike?

The DT on the Kaffenback might be a bit fat - there are some variations on modern steel tube diameters. I'll have to email Planet X to ask them the tubing diameter. 70s road bikes have quite skinny DT's, f.e. Reynolds 531 downtubes typically measure 28.6mm.

 

[ninety]

Can you maybe mod an old set of friction clamp-ons? I'm guessing that stem mounted shifters or gripshifts right up on the flats aren't options? Granted, it'd look a bit weird, but it'd be cheap...

 

[tee-one]

Can you weld? Get an old steel clamp on set, Cut it down the middle and weld a piece in to make it wider . Grind, Paint. done... Would cost as much as an inch of welding wire to do...

 

[hamster]

See the thread on retro MTB about bar-end shifters - there are some neat Jagwire wotsits to turn downtube levers into barcons..

 

[daccordimark]

It does look like the downtube is bit fat even though the seat tube is old school 28.6mm. I'm sure they'll tell you when you email them. The other alternative is a 2nd hand oldie or not so oldie with bosses of course.

Mark.