Early 80s. Just like WW said. That is the bumper that was being used.
Indeed, that bumper and weight bolt were used in the eighties.
But I believe that bumper and weight bolt were also used in the seventies as well. No?
The black bumper like that has exactly the same dimensions as the KU bumper.
The Diamond Series cues, for example, had both the brown Brunswick KU bumper and the black version. That is how they are pictured in the catalog, and I have seen them with both.
I do believe we have seen original Joss cues from the seventies with the black bumper as well as the brown, no?
I am not entirely sure that the bumper color alone can be used to accurately date a Joss.
I do not wish to argue with you, just discuss. You have been a wealth of information on Joss here on AZB and I respect your opinions. You have owned a number of them and certainly know a lot about them. I will stand corrected if you have definitive information.
Back in about 1992 when Janes made my jump cue I ordered a new bumper for my old Joss at the same time. When I ordered it he asked "black or brown?" and he said they were the same bumper in dimensions and the cue might have had either one originally.
My cue had a brown bumper. I ordered black. I didn't know it would matter many years hence but I still have the original anyway as well as several brand new KU bumpers to replace it if I want to. The bumper he sent was an exact match to a KU but black.
My cue currently has the original brown KU on it which shows its age. I will keep one new KU in case it ever needs replaced.
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