Last week we sidled in from our new home in West Oxfordshire, for a sleepover back at our old stomping ground of Cowley Road.

The wives cycled down to Eau de Vie for a massage while the men babysat. When they returned, my wife was far from chilled: “Some IDIOT has locked their bike on to mine!” She’d left a stroppy note attached to the bike locked to hers, before stomping back.

This is an old bike thief’s trick. They lock their jalopy in a bike rack on to a nice bike as if by accident. The owner of the nice bike has to leave it in situ until they can resolve the problem, probably by waiting for the person who has locked their bike to release it when they ride away.

My wife’s bike is a sturdy Dutch Gazelle, the bicycle equivalent of a Volvo estate.

While it isn’t as thievable as a Pashley, it’s headed that way.

Immediately wise to this ruse, I rushed down Cowley Road to investigate.

The bike shops have huge bolt croppers they can bring to bear in such cases, but they were all closed by 6pm. And in any case, I am not sure morally or legally where you’d stand on cutting away someone else’s lock to free our own bike.

You’d leave their bike unlocked and vulnerable to immediate theft, unless you locked their bike with your lock – which all gets a bit complicated.

I was pretty worked up by the time I got down there but as it turns out, the Gazelle was fine. There was just a screwed up note on the pavement where the other bike had been.

It was a relief but brought starkly to mind bike security. Apart from malicious locking-on, how can you keep your bike safe?

At the risk of stating the blindingly obvious, never leave your bike propped against a wall and locked ‘to itself’ unless you don’t mind getting the bus home later.

Lock your bike to an immovable object. Use Sheffield racks – the black hoop racks. Avoid ‘wheelbenders’, the front-wheel-only racks whose moniker is self-explanatory. If you lock-on to signpost poles, make sure that your bike isn’t in the way of pedestrians. Also make sure there’s a sign at the top of the post. Bikes can be lifted up and over the top of poles as tall as three metres.

Lock the bike through a part of the frame and the rear wheel. Don’t lock just a wheel – this leaves your bike especially vulnerable, as wheels are easy to detach.

The problem with D-locks is that it’s easy to put car jacks into the space formed inside the “D”. Car jacks can shatter even the highest-rated D-locks in minutes.

With a D-lock, get your knees dirty and lock the bike as low to the ground as you can – i.e., lock it around the bottom bracket/pedals area. This makes it hard for jacks and power tools to access and break the lock. Also try to ‘fill’ the space within the D-shape with a combination of bicycle and fixed post. This again prevents anyone squeezing in a car jack or power tools.

If you are looking for a new lock, get a gold-rated miniature D-lock – these are too small to get a car jack inside and they are too tough to be cut with bolt-croppers.

Caveat: they’re heavy and too small to use as a normal D-lock, so pair this with a Kryptonite chain to go around wheel/frame/anchor.

onyerbike@nqo.com