Uber’s Jump Bikes unit has gotten a green light from San Francisco to add 250 electric bikes to its free-floating rental service, doubling its quota in the city.

“The No. 1 thing people have been asking for since we launched is more bikes, more bikes, I can’t find a bike,” said Ryan Rzepecki, CEO of Jump, which Uber acquired in April. “It will be amazing to have more.”

Since starting service in January, the bright red e-bikes have averaged eight to 10 trips a day, he said. Rzepecki thinks usage will stay that high even with the new allotment.

Jump plans to start adding more bikes immediately following the approval from the Municipal Transportation Agency and expects to be up to 500 within a week. (In September, it added 50 more in the Presidio, which is administered separately.)

Most of the new cohort will go to the existing service area — the north part of the city, extending west through the Richmond District and south to Bayview, and ending just short of North Beach. Some may go to adjacent neighborhoods, Rzepecki said.

The MTA administers the 18-month pilot program under which Jump operates. Its mid-point evaluation was positive, finding that public demand for the shared e-bikes is high and complaints about them blocking sidewalks when parked are low. Jump’s bikes must be locked to a pole or rack, reducing the chance that they’d sprawl across sidewalks.

The MTA’s only quibble was that some lower-income communities have reported under-service, although the agency said that 55 percent of Jump trips start or end in such communities. It will work with Jump “to improve geographic equity and distribution,” spokesman Ben Jose wrote in a blog post.

Jump now operates about 4,000 e-bikes in 10 cities, including Santa Cruz, Sacramento, Santa Monica, Chicago, New York, Washington, Austin, Texas, Denver, and Providence, R.I. Rides average about 2.6 miles, which Rzepecki said shows that they are replacing car trips.

Riders can book a bike either through Jump’s app or Uber’s. Rzepecki said the majority of riders use Jump’s app, but he expects to see more shift to Uber over time.

Acquiring Jump is part of Uber’s push into more forms of transportation other than cars. Through Jump, it applied unsuccessfully to run an e-scooter rental program in the city. Jump is now appealing its rejection.

Rival Lyft likewise is branching into two-wheeled transport. It is buying Motivate, which runs the Ford GoBike docked rental program and other bike rentals, and it also applied unsuccessfully to rent e-scooters in San Francisco.

Carolyn Said is a San Francisco Chronicle staff writer. Email: csaid@sfchronicle.com Twitter: @csaid