Further and further, I am slipping into bicycling geekdom. And the further I slip, the more my geekiness is costing.

I’m used to doing rather well in the “What’s your bike like?” stakes. I’ve got six so far, and I say “so far” advisedly: that is, I haven’t stopped yet.

To be fair, two are “projects” – only four are rideable. The projects are both Raleighs, one of 1950s vintage and the other from the 1970s, both with Sturmey Archer hub gears and rusted chrome wheels.

I’m not quite sure how they’ll end up – one properly restored and the other a single-speed, I suspect.

Of the four that I do ride, the oldest, my first love, cost me a month’s wages at Bike Zone back in 1996. It’s a Kona, a real thoroughbred, with a long stretch to the handlebars, giving the ride a lithe, racy feeling. Its oversized tubing with matt burnt-orange paint job still looks the business today. It is perfect for flying over a quick single track in the Chilterns and skidding down stony bridleways up in Yorkshire.

Of the others, two are Specialized: the first, a shiny black Sirrus from BeeLine, is a racer with flat handlebars for city riders who can’t face dropped handlebars. Fairly new, with carbon forks and seat post, it is feather-light. It’s a show-off, bum-pinching, espresso-swilling Italian sports car of a bike, and it eggs you on to push harder and harder on the pedals, flying on what feels like a frame made from taught wires, not aluminium tubing.

The other Specialized was sourced by Oxford Cycle Workshop (RIP), who found me this late-80s Rockhopper mountain bike, like the one I first rode back in the day. It was stripped down, the gears removed and converted to single speed. The mudguards aren’t a great look but that doesn’t matter: it’s a workhorse, my “pub bike”, a bike I can leave anywhere and be sure it’ll still be there when I get home.

My fourth (rideable) bike is a Brompton. The acquisition of the Brompton arguably marks the moment I succumbed to geekdom, to bike-craziness, to the idea that the ideal number of bikes for anyone is the number of bikes you own – plus one.

It’s a pre-loved red folding bike with six gears, an extra-length seat post and a squeaky new saddle. I bought it from a friend, which is in my view the only way to buy a Brompton as new they are way too dear and any second-hand example is almost certainly nicked.

Do I ride them all? Yes, even the Brompton gets about 10 outings a year when I take it on the train to meetings in London and Cambridge. Do I need four (six) bikes? Well, you can answer that one yourself.

I fell further into geekdom this autumn. It was the Kona wot did it. It is well loved and well used, so well used in fact that over the years I have replaced every single part of it except the frame. There is literally nothing on it now that was there when I bought it. Then, on a bumpy track outside Charlbury, a crash bent the frame. That, I thought, was it.

Happily, an alchemist called Jim at Walton Street Cycles was able to bend and save the frame. And so I treated my first love to new gears. Not the cheapest gears mind, no, £350’s worth of Shimano XT.

Oh, my wife knows. I just tell her she’s damn lucky it ain’t sports cars or vintage planes that float my boat.