Handlebars on London's rental e-bikes are carrying far more bacteria than a public toilet seat, according to laboratory testing commissioned by the Daily Mail, which sampled bikes from Forest, Lime, Voi and Santander Cycles, also known as Boris Bikes.
The newspaper said the average handle it tested carried more than 100 times as many germs as a toilet seat, while the single dirtiest bike was 418 times filthier. Testing also turned up bacteria indicating recent "faecal matter contamination."
More than 100,000 Londoners use rental e-bikes to get to work each day. Transport for London estimates that rentals account for roughly 10 per cent of the 1.5 million cycle journeys made across the capital every day. Lime introduced the first e-bikes in the UK in 2018, and rental schemes have since spread to nearly every major British city.
How the bikes were tested
The Daily Mail used a method called surface-swab enumeration testing, which gives an indication of the overall bacteria present on a surface. A sterile swab was used to sample the handlebars of one bike from each brand, and the swabs were sent to a professional laboratory, where the bacteria were transferred to a petri dish and incubated at 32.5C for three days.
Scientists then counted the visible colonies that had grown, producing a score known as the aerobic colony count. A toilet seat in an office gents' bathroom was also swabbed for comparison, returning a reading of 430,000 colony-forming units (cfu).
Results by brand
The cleanest bike tested was a Voi, one of the less common rental brands, with an aerobic colony count of just 1,010. Every other bike tested carried significantly more bacteria.
A Santander Bike returned a count of 2,700,000, 27 times dirtier than the Voi and more than six times the reading from the toilet seat. A Lime bike came in at 60.6 million, more than 140 times the toilet seat figure. The dirtiest of all was a Forest bike, with an aerobic colony count of 180 million, 418 times greater than the toilet.
Dawn Mellors, technical director at Melbec Microbiology, the laboratory contracted for the tests, said heavier contamination could explain the higher counts but cautioned that other factors "need to be reviewed." She said that if some bikes had not been used recently and temperatures were high, organisms on the surface would start to die off, making the numbers appear lower.
Faecal bacteria found on Forest bike
The Forest bike was the only one for which the lab was able to isolate specific bacteria, which Mellors said does not mean Forest bikes are dirtier overall, but likely reflects hot weather and postal delays killing off bacteria in the other samples before they reached the lab.
The lab found more than 1.3 million colonies of Staphylococcus aureus on the Forest bike, the bacterium that causes staph infections. Mellors said this usually indicates skin bacteria and, while typically harmless, is classified as a pathogen that can cause infection if it enters the body.
The tests also revealed Faecal streptococci and E. coli in considerably high numbers. Both can cause infections or food poisoning and indicate faecal contamination. Mellors said the contamination could come from humans or from animals such as bird droppings, and that because such organisms do not survive long in the environment, they usually point to recent contamination.
The findings echo an earlier study of 50 e-bikes across London by Initial Washroom Hygiene, which found many of the rentals "riddled" with germs, including biological residue from skin cells, sweat, saliva and food, and in some cases faecal matter.
The Daily Mail noted its results are not on a par with peer-reviewed research and were based on a small sample of just one bike per brand, meaning it is not the case that every Forest bike will be filthy, nor that every Voi is guaranteed to be clean.
Company and TfL responses
Mellors said the results indicate bike handles can be a source of pathogens, and that handles should be disinfected before use or hands washed afterwards.
Lime said its bikes are washed regularly but that members of the public should still wash their hands after use. A TfL spokesperson said the findings related to a very limited sample and did not appear to show E. coli, faecal streptococci or Staphylococcus on the Santander Cycles sample tested. The spokesperson said cycle handlebars, like any frequently touched public surface, can naturally carry environmental bacteria, and that TfL encourages customers to wash or sanitise their hands after a journey where possible, adding that touch points including handlebars receive regular cleaning as part of its maintenance programme.
A Voi spokesperson said any frequently touched public surface, from door handles to Tube poles to shopping trolleys, carries some level of bacteria, and that the data did not support the idea that Voi bikes pose a particular hygiene risk, though the company takes vehicle hygiene seriously. Lime and Forest declined to comment on the specific findings.
