Bikes are not free. They're just free at the point of use, like the NHS or hotel toiletries or dinner at your mum's. You've already paid for it somewhere else. But they're cheap... aren't they?
Yesterday's Independent reckons London commuters can save a couple of grand a year by cycling instead of taking public transport. Their article is a bit light and could have done with some more case studies, but it's good to see another reason for cycling being pushed in the papers.
The Independent article quotes Sustrans's figure of running a bike as £75 a year. That's far too low if you cycle every day. In that case I'd put it more like £150-£250 per year.
It's hard generalising for all cyclists, but I keep a record of all my bike-related bike expenses for tax purposes, so can be pretty accurate with my own figures. (Obviously, as that's for tax, it's not in my interest to minimise costs.)
Last tax year I spent £360 maintaining my bike, accessories and bike clothing, for a total use of about 4,500 miles (7,200km). Most of that was for replacing worn bits (chains, cassettes, waterproof jacket, new wheel to replace the one turned into a Thomas Heatherwick-style sculpture by London potholes etc.)
Not cheap - but certainly much cheaper than if I'd done all those journeys by public transport, never mind taxi. A rough calculation suggests I'd have paid at the very least £1800 on buses and tubes for the same movements.
Though, in fact, about half the journeys I made would have been impossible or impracticable by bus or tube: short hops around town, jaunts out to places remote from bus stop or train station, or spontaneous side trips.
A separate question is: how much have I saved by making all my out-of-London journeys by bike and train, instead of car? Tricky to judge, as there are obviously lots of trips I might have done by car which are impossible or impracticable by bike; but as it happens all the places I visited (holiday, relatives, work) were convenient by rail and cycle. This boils down to rail fares versus car costs. I spent £640 on trains; running a cheap car for the same outcome would, a very rough calculation suggests, have cost me at least £3000 in petrol, depreciation, insurance, servicing and so on.
(I don't own a car because it's all hassle and expense and wouldn't enable me to do anything I can't or won't already do. I hire a car whenever I need one, which in the last five years has been once, for ten days; otherwise we simply don't need one.)
Which is all very nice, but saving money is not why I cycle. I cycle because it's fun and I love being in control of where I go and when.
Nevertheless, according to the above, I've saved myself something like £23,000 in the nine years since I moved to London. Which does raise the question: where's it gone?