(santander being a chain of banks in the UK, they're called Santander bikes because they usually have santander branding. i think it was a sponsor or something)
calling them boris bikes in 2025 is so funny that word probably has not been used for 10 years and boris johnson is now so far away from their creation now that he was PM and stuff. but the phrase is so much funnier than the other term me and my friends used to use which was "Santander Bike"