After testing a new set of modified fare gates at Fruitvale Station — equipped with plates that pop up, like shark fins, once the gates close — BART officials made a conclusion: They’re not worth the effort.

The gates, installed in July, succeeded in at least one measure, reducing fare evasion by 17%. But they also created an “unreasonable maintenance burden,” largely because fare cheats kick the plates when jumping over them, Assistant General Manager Tamar Allen wrote in a memo to BART’s Board of Directors.

Constant battery by fare evaders upset the delicate architecture of the fare gates, which had to be synchronized so that the right and left plates would come up and retract at exactly the right time. Combined, those factors meant triple the number of repairs as normal gates.

Although BART engineers tried to strengthen the pop-up mechanism, they had to constantly fix damage, Allen wrote. Eventually, officials grew weary of the cat-and-mouse game.

“Keeping this old equipment that precise was just a real effort,” Allen said in an interview. She told the board the “modification” will be removed this week. Crews disabled it Monday morning, returning the fare gates to their normal state.

“It’s a learning process,” said Board President Bevan Dufty. “I never expected the first prototype or the second prototype was going to be the answer.”

Meanwhile, a set of stacked gates at Richmond Station are still operating, in spite of jeers from commuters and a slew of guillotine jokes on Twitter.

The double-decker version reaped better preliminary results, causing fare evasion to drop by 50% to 60% at the Richmond entryway, Allen said, though she cautioned that the data were based on a small sample in a narrow time window.

Some board directors have pressed for a full gate replacement, a move that they say would help deter transients from taking shelter on BART trains, and possibly curb crime on the rail system. Overhauling all 600 gates could cost $150 million to $200 million, but it might end a cheating epidemic that siphons an estimated $25 million a year, and it could make the system more attractive to paying customers.

The board directors will likely discuss the recent gate test models at their Sept. 26 meeting.

Rachel Swan is a San Francisco Chronicle staff writer. Email: rswan@sfchronicle.com Twitter: @rachelswan