Bicycle Mechanics - Mounting DT Shifters w/ no Braze Ons!

I am trying to upgrade the shifters on an old Nishiki I picked up. It's currently a five-speed setup, but I would love to put 7 speeds onto it. I'm used to downtube shifters, but this particular International frame doesn't have braze-ons. I'm not really interested in the Sora shift/brake levers; I like having my shifters and brakes separate. Is there any sort of adaptor that would let me mount braze-on shifters onto my braze-on-less downtube? I've done some looking, and found nada.

Unless of course someone wants to sell me some 7-speed bar-end shifters:D

Am I screwed, or is this possible?

Entirely possible. In the seventies and before they made bands with shift bosses brazed on. You simply clamped them to the downtube. Only problem was that there usually was a boss brazed on the downtube that kept the clamp from sliding down the tube. Here is a pic. http://cgi.ebay.com/CAMPY-DOWN-TUBE-SHIFTERS-VINTAGE_W0QQitemZ180112347085QQihZ008QQcategoryZ36140QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Tim

My bike does have some heart-shaped braze ons that kept the housing guides from moving around. However, I don't really want to used friction shifters anymore; they're better for long relaxing rides, and I'm riding mostly in heavy traffic. I'm preferential to indexed shifters because I can just flip the lever without fiddling too much.

Any other possibilities short of having stops brazed on?

I think you can get clamp-on down-tube shifter mounts that work with standard down-tube shifters. However, a lot of clamp-on DT shifters use proprietary mounting design and won't work with standard indexed-shifting design. Harris Cyclery is probably your best bet here.

One option is to get old mtb trigger-shifters and use a flat bar, kind of like the setup I've got on my commuting bike. It's excellent for this application - commuting in traffic.

http://www.unc.edu/~cupery/pics/bikes/Schwinn_commuter/small/02_IMG_8405--bars_top-view.jpg (http://www.unc.edu/~cupery/pics/bikes/Schwinn_commuter/small/02_IMG_8405--bars_top-view.html)
http://www.unc.edu/~cupery/pics/bikes/Schwinn_commuter/small/03_IMG_8407--front_view.jpg (http://www.unc.edu/~cupery/pics/bikes/Schwinn_commuter/small/03_IMG_8407--front_view.html)

SunRace makes 6 and 7 speed clamp-on DT shifters. You can get them from Harris and bike Tools.
Top

SunRace makes 6 and 7 speed clamp-on DT shifters. You can get them from Harris and bike Tools.
And these should be Shimano-compatible.
http://harriscyclery.net/itemdetails.cfm?ID=1018

Another possibility is to buy the bar-end adapters that Rivendell sells and mount 7-speed indexing downtube shifters on them. Check with Rivendell to see if they will accept the backing plates that come with the shifters and are required for the indexing to work. Rivendell also sells a clamp on downtube cable housing stop which you will need with barcons.

And, yes 7-speed barcons seem to have disappeared from the world. I don't know why they are so hard to find these days.

And, yes 7-speed barcons seem to have disappeared from the world. I don't know why they are so hard to find these days.
I've seen NOS sets go for around $130 on eBay.

I've seen NOS sets go for around $130 on eBay.

OUCH! New 10-speed barcons don't cost that much.

OUCH! New 10-speed barcons don't cost that much.
They're not rare commodities either :)