Hertz's e-bikes come in two slick-looking models, powered by lithium ion batteries and nearly silent motors.

BBC: Rent an electric bike in London

On 6 June, Hertz became the first major rental car company to offer e-bikes, stocking a dozen at its Marble Arch location.

BBC: Rent an electric bike in London

Barclays has made about 5, 000 traditional bicycles available at hundreds of docking stations throughout the city, which makes it a more convenient option than Hertz's mere dozen e-bikes at a single location.

BBC: Rent an electric bike in London

"When we put e-bikes in hilly areas of London I don't think we're going to have any shortage of riders... if anything, we're going to have a shortage of bikes, " says the mayor's cycling commissioner, Andrew Gilligan.

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