Knightriders (1981)

A traveling troupe of jousters and performers are slowly cracking under the pressure of hick cops, financial troubles and their failure to live up to their own ideals. The group's leader, King Billy, is increasingly unable to maintain his warrior's rule while the Black Knight is being tempted away to Los Angeles and stardom, as they all have to ask why they were here in the first place.

Simple 3 ball and 3 club juggling appears many times throughout this film. Some examples are:

At 0:02:46, during the opening credits, a jester walks across juggling 3 balls for 2 seconds at an outdoor festival.
At 0:11:33, a parade is led by a 3 ball juggler followed by a 3 club juggler, shown for about 30 seconds.
At 0:37:48, the jester is seen again for about 15 seconds juggling 3 balls.
At 1:01:42, during another parade, we see a 3 ball juggler riding in a motorcycle sidecar.

The entire movie may be seen here.