solution needed - campag record gear levers on shimano boss

[foz]

I could file the tab off, but then the base plate would just spin on the boss. I either need to make or adapt a base plate, or file both bosses off completely and use a clamp on boss. Will try the base plate first

 

[foz]

I've been looking at these again tonight, and a shimano 105 6 speed gear lever will fit directly on to the boss, without using the curved washer. There is a little play, but I can't tighten the lever down as the screw thread in the boss is 4.5mm, not the usual 5.0mm. I'll probably retap the threads to take a standard 5.0mm screw.

A quick comparison of the frame boss and the flat side of the curved washers makes me think they're the same, but the bosses on my frame are slightly smaller diameter.

Does anyone know the exact dimensions of the shimano type B gear lever bosses? Or can confirm that they're exactly the same as the curved washers?

 

[hamster]

Thanks for all this, I didn't realise the threads were different too. Something to check in a resto I am about to start - maybe I have to braze on new bosses before painting!

 

[foz]

I haven't confirmed myself but have read that the threads are 4.5mm. A 5.0mm bolt definitely won't fit in mine.

As soon as I can find some suitable material, I will make a set of new base plates with campag outer diameters but the inner hole will fit the shimano boss, not the much more common campagnolo square boss.

I have measured my bosses and also the equivalent part on some shimano curved washers. The bosses are slightly smaller, so I'm looking for a spec sheet or something to confirm what the dimensions should be.

If you have a frame with shimano type B bosses, could you measure them? diameter of the circular part, total length along the long axis (diameter plus however much the tab protrudes), and width of the tab?

 

[Midlife]

Isn't the "B type" boss the single one on the top of the frame for aero type levers?

Shaun

 

[hamster]

Foz, just been to the shed and had a check...mine are Campag and M5. Relieved but sorry i cannot help.

 

[foz]

No problem Hamster! Shaun, possibly, I don't know for sure... I've seen them referred to as B type on other forums

loosescrews has the A type (campagnolo standard) https://www.loosescrews.com/product/shi ... s-m5-each/

and "4.5mm" type (the ones I have) https://www.loosescrews.com/product/shi ... boss-each/

I have a plan, I just need some 2.5mm thick alloy plate!

 

[Midlife]

Blimey, I never thought they would still be available, if push comes to shove I might be able to get you a backplate cast in chrome.

Shaun

 

[foz]

Shaun, I'd be very interested, if you can! Can you check and let me know? Would save me trying to bodge one!

Thanks!