Are shift lever "posts" universal?
 

I want to add a single-sided clamp-on down tube shifter to my bike.
I have a set of Suntour stem shifters, so all I need is the clamp, if lever posts are universal. There are lots of Simplex clamps available, no Suntour that I can find.
Thanks.

Yes and no. I'd think the French are different, but eventually everyone settled on the Campagnolo standard. Campagnolo single lever clamp-ons are sometimes on ebay...

Huret is different from Simplex too.

Suntour stem shifters are also not all alike, as time went on they changed.

I don't have Shimano on my bikes, but IIRC, they made their own shift lever "stud" style that does not work with most of the Euro shift levers.

Chombi

I agree. While most braze on post and shifters are pretty standard butmoving a clampon shifter from its brand of clamp to another brand clamp can be problematic.

Thanks ladies & gentlemen, I'll source a complete set.