I've got an hr bates bar frame with braze on boss for downtube shifters. I have some campag shifter but any I have Googled have a lever stopper that looks like it needs a square section to fit over which is part of the braze on boss. The one I have doesn't have that. Any ideas? Quite stumped at the moment. enter image description here

enter image description here

  • Have you tried fitting it up? what does it look like on the bike? The square section may not be necessary here as the protruding stub has the flattened sides to stop the washers turning and none of the parts you show have shaping to interact with the square in newer braze-on designs.
    – Noise
    Commented Aug 24, 2022 at 9:56
  • Yes it all fits nicely, but I can push the shifter lever forward without a stopper so that it scuffs the frame. Not a big deal I suppose. Commented Aug 24, 2022 at 11:44
  • It's possible you are missing part of the shifter
    – Noise
    Commented Aug 24, 2022 at 12:30
  • They would have been on a band clamp orginally with the stop as part of the clamp
    – Noise
    Commented Aug 24, 2022 at 12:34
  • @Noise not if you have brazed on bosses Commented Aug 24, 2022 at 18:03

2 Answers 2


I'm not an expert on the history of downtube shifter bosses, but what's going on here may be the bosses on this frame were made to emulate the boss part of certain Simplex band clamp type downtube shifters. If you google around, you can see various evidence of Bates often speccing Simplex.

enter image description here

If the dimensions/threading of the bosses were enough like a standard modern one in every other way, you could look at getting some downtube shifter bosses from a framebuilding supplier and simply cutting off the post part, leaving you with just the square, getting the hole just right, then taking the paint off the frame in just that area and epoxying or brazing them on.

enter image description here

It's also possible they're meant to be used with some shifter or another that simply doesn't have a stop.

  • Tangential: Are those springs? I'm in no way a friction shifter expert but I don't remember my old Suntour, Simplex, or Shimano non-SIS shifters having any spring action. Though I admit I'm too young to have seen any high-end friction shifters in my life, as even the lowest end rear derailleur available was the good old RD-TY20 and its horrible switchable friction/SIS lever.
    – jayded-bee
    Commented Aug 24, 2022 at 7:30
  • Yes possible that it isn't meant to be used with a shifter with a stop. I just can't find any example of it online. Commented Aug 24, 2022 at 11:46
  • @AndrewWelch as you can see in the catalog diagram above, there were some Simplex shifters that used a spring instead of a hard stop, and the spring was I think that's another clue it could be Simplex. The spring can use the flatted part of the post as its anchor. Commented Aug 24, 2022 at 16:20
  • 1
    The shifters are definitely Campagnolo. Commented Aug 24, 2022 at 18:03
  • @AndrewWelch Ah, I didn't understand that these shifters definitely went with this frame at some point. Commented Aug 24, 2022 at 19:28

I believe the shifter boss is made for Huret shifters. This link may help: https://www.disraeligears.co.uk/site/huret_accessoires_cycles_cyclomoteurs_motos_-_1975_page_13.html

  • I actually own one of those shifters as well coincidentally! but this frame has the bosses brazed onto the frame. However, maybe the bosses were used for cable stops and not shifters at some point ? Commented Aug 24, 2022 at 18:04
  • I look at the linked diagram and see the square that's missing from Andrew's brazeon is actually part of the Huret band clamp, so I'm not sure how this answer helps.
    – Noise
    Commented Aug 24, 2022 at 19:45
  • You are correct. My error. Looked at the wrong picture.
    – P. Barney
    Commented Aug 25, 2022 at 3:43

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.