Kind of a technical item, but I wasn't sure anyone in Bicycle Mechanics could give me a straight answer, so: What kind of 4-speed shifter (Simplex, Cyclo, etc) do I need to look for
to attach to a brazed-on boss on my downtube? It seems all the ones I've seen have an attached (and attaching) metal clip to harness to the downtube, evidentally for bikes with no shifter mount braze-ons. Are these two distinct mounting systems, or will the ones with the circlip mount to the boss (after I take the clip off)?

198

I believe the shifter in your photo, once disassembled, can be reassembled on a Cyclo or Huret or Simplex boss. But I can't remember exactly how I know that.

I think it's as follows. I had a Lenton Sports that came to me with a two speed Cyclo derailleur and the Cyclo shifter in your photo on a Huret clamp mount. I later moved that shifter, and some of its associated hardware, onto a ca 1950 Holdsworth with the Simplex style boss. It was all compatible.

That's good news, RH. I don't know who made my boss, but it is cylindrical, threaded internally and is about 1/4" o.d. This is the matching shifter for my Cyclo Benelux Mk7 derailleur, so I think I'll try it out. Thanks for the tip.

198

I'm not sure if this is what you're asking for but I'm working on an old French bike now which has a Simplex four speed drive. The shifter boss cylindrical portion measures 9.0 mm in diameter and is 5.6 mm tall. There is a square base under this. The screw thread is 5 mm but it appears to more coarse than the normal 5mm fastener. I don't have a metric thread gauge.



This is the shifter.

No, that doesn't sound right. I'm not sure I've ever seen something like that.

Yes, that's the one I'm familiar with. I believe a Cyclo, Huret, or Simplex shifter will fit that boss. That's what I assumed [MENTION=160128]1989Pre[/MENTION] had.

Thanks for the information on the Simplex, 73S. My boss is identical to yours. I imagine the Cyclo shifter has the same mount as the Simplex. That's a great photo of the dis-assembled apparatus.
RH: The boss could well have an o.d. of 9mm, like 73 says: I came up with .25" with a tape measure, and 9mm is only .1" larger.
I think I'm 90% there. I appreciate it.


198