COMEDY REVIEW : Smothers Brothers’ Shtick Still Works--in Small Doses : Their sibling rivalry was well-received by the family-oriented crowd at Knott’s Berry Farm, but 55 minutes of it proved too much.

Halfway through the Smothers Brothers’ late show at Knott’s Berry Farm Friday, Dick (in case you forgot, he’s the one mom always loved best) tried to make a point with Tom (he’s the one she didn’t) about how comedy needs to keep evolving to stay fresh.

As primly condescending to poor Tom as ever, Dick said vaudeville may have had them roaring years ago, but it might have them snoring today. These hip, know-it-all, contemporary audiences want something different, he said, not the same old kick in the pants.

Dick should have taken his own advice. The Smothers spent most of their 55-minute set offering up the well-traveled basics of an act that, according to Dick’s reckoning, has been around 32 years.

The family-oriented crowd loved it--proving once again that nostalgia is as good an entertainment hook for middle America as any--but it was a pretty tired business, big on practiced delivery and low on inspiration. As usual, the guitar-wielding Tom played the puckish but always confused schlep to the exasperated, sometimes downright nasty Dick, his big bass at his side.

Come on! You guys are over 50; haven’t you found a way to get along yet? Family therapists are good at this sibling rivalry stuff.

OK, that’s flip. The Smothers Brothers have made a long and successful career working off that one premise, following in the tradition of Abbott and Costello and even the great Laurel and Hardy, other duos that turned misunderstanding and the art of not getting along into a cartoonish primal condition.

It worked well for the Smotherses on their many folk-and-comedy records and especially during the run of their popular (and, to their credit, political and controversial) television variety show during the late ‘60s.

But those forums gave them to us in punchy, tightly controlled doses, from three-minute gag songs to three-minute TV skits. A 55-minute helping in a large venue like Knott’s Good Time Theatre--where, except for in the front rows, it was nearly impossible to take advantage of Tom’s signature face-making--can be too much.

The routine lacks exploration or new angles. Tom still fights to find the right musical key while Dick waits impatiently. Dick still gives self-satisfied renditions of popular tunes (this time out, he served up a spirited, intentionally mawkish “You Light Up My Life”) as Tom watches, appropriately cowed by Dick’s talent.

Nevertheless, the show was genuinely amusing when Tom, as he always does, got his one chance to turn the tables. Speaking in elaborate and apparently correct Spanish, Tom gave a speech while Dick gaped, obviously the butt of the joke.

As “The Yo-Yo Man,” Tom displayed a series of accomplished yo-yo tricks that held the audience’s interest, especially the children’s. You could almost ignore all the silly patter--”We are now entering the state of ‘Yo’ “--and just enjoy Tom, an overgrown kid if there ever was one, doing what every talented kid loves to do: show off.