staehpj1

I am fixing up an older touring bike (late 80's Nishiki Cresta frame). It currently has a Crane GS deraileur and a 7 speed freewheel with bar end shifters. There are no down tube shifter bosses, but I want down tube shifters. I have seen clamp on shifters on ebay.

If I buy the clamp on shifters what are the odds that I can take the levers off and fit some 7speed 105 dt shifters on the bosses of the clamp? I am thinking that the bosses are pretty universal, is this true?

If I use a Deore xt 7 speed rear deraileur and a set of deore xt hubs that I have sitting around will that index with a sis 7 speed 105 downtube shifter?

top506

Why not just get a set of 7-speed index clamp-on shifters?
https://harriscyclery.net/itemdetails.cfm?ID=1018
I'm upgrading an old Shogun with a set of these.
Top

staehpj1

Sounds like a good answer. I had looked there and somehow got the idea they were 6 speed only.

Cynikal 

I'm using the same frame for a single speed CX bike. I was going to do some research on the frame. Can you post a picture of yours?

Here is mine

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HillRider

I'm not sure about Shimano clamp-on downtube shifters but the Sun Tour clamp-ons I've seen had bosses that wouldn't accept regular downtube shifters.

staehpj1

Mine is different. It is set up for caliper brakes and has old Dura Ace side pulls on it. I will snap some pics if I get a chance, but I am on a really crazy schedule for the next month or so (getting ready for upcoming surgery) so I may not get to it right away.

Well I may find out since I bid on a set of 105 clamp on downtube friction shifters on ebay before I saw Top506's post. If they have "normal" bosses I may put a set of 105 7 speed sis shifters on them. Otherwise I may just stick with friction only.

staehpj1

Mine is a bit different than yours. Caliper brakes, shift cables under BB, etc.

simplify

I think it will work, even though the shifter/boss interface may not be perfect. I just did this with an old clamp from a set of early 80's Shimano 600 friction shifters. I used that clamp and bosses to mount a set of NOS Sante 7-speed indexed shifters. The left shifter fit *perfectly* into the old mount. The right shifter does not fit perfectly into the mount, but it fits well enough to work flawlessly and it's very secure.

Edit--just realized that the clamp and bosses I ended up using were from a set of Dura-Ace 6-speed indexed shifters. It's exactly the same clamp as the 600 friction shifters used, but included the sort of flat chrome base thing that the shifter unit mounts on. Similar to the half-moon shaped base that sits against the downtube with a braze-on boss, only these base units are made to fit on the clamp. I've seen shifters sold with a choice of either type of base.