Faulty brakes have forced Lyft to remove thousands of its electric bikes from three US cities.
Riders complained that front braking was “stronger than expected” on the assisted bikes, it said.
About 3,000 Lyft bikes currently in use in New York, Washington and San Francisco, are being removed.
It said an “abundance of caution” led to the withdrawal of the bikes from the 17,000-strong fleet which it operates across the three cities.
The assisted bikes, which are fitted with an electric motor to help people get around urban areas, will be replaced by traditional pedal-powered alternatives.
“Safety always comes first,” said Julie Wood from Lyft partner Citi-Bike, which operates the services in the three locations on behalf of the ride-sharing company.
Ms Wood said riders had made a “small number of reports” about the problem, which led to brakes being jammed on sharply during some journeys.
Updated electric bicycles which do not suffer the glitch are being prepared for deployment in the cities, she added. No date was given for when the replacements will be available.
Lyft debuted on the New York stock exchange in late March.
Reports of problems with the bikes came soon after the scooter hire firm Lime reported that a software bug led to injuries for a “small number” of its riders.
The bug meant that the scooters suddenly applied the brakes when riders were travelling at full speed downhill.