Canon FD Question: aperture ring setting does not always transfer to camera? (3rd party 100/3.5 macro)

[dynachrome]

I have a collection of 100mm f/3.5 Macro lenses made by Cosina and sold under other names like Vivitar. Some people refer to the lens as the "plastic fantastic" because of its build and appearance. I have had fun with them and I think I have at least one in every mount that was available. Recently I found one on the auction site in very nice condition and in Canon FD mount for a whopping $15.50. I took it on vacation this past week. The camera I used it on was a Canon New F-1 with the Finder FN. With the lens mounted on the camera, I rotated the aperture ring. The meter circle would not move past the f/11 position. When I got home I tried another example of the lens but on an F-1n. The same thing happened. I wonder why?

 

[koraks]

I've edited the thread title to add some more details; maybe this will help in getting some more on-topic responses.

Now you make me want to go shopping for one of those lenses...

 

[88E30M50]

My early F-1 does that as well, but I don't see it happen on my F-1N or any of my other Canon A series. I figured that it was a camera issue and sent the camera off for a $275 CLA. The issue is mostly gone but it will still occasionally stick. It never occurred to me that it might be the lens rather than the camera. I need to get that camera out again and look deeper into this to see if it might be lens focused and not an issue with the F-1.