Blatting home along the Clapham Road a while back I encountered a new and terrible form of road user. The usual form along this stretch of road is for whatever bunch has aggregated at the Oval traffic lights to set off en masse and quickly thin out, the slower riders dropping back to leave the faster ones with the road ahead empty but for the odd traffic light jumper, who is invariably quickly hauled in. Half the pleasure of watching someone jump the lights is in the prospect of blowing past them yet again on the way to the next set…

At night, of course, the process is given added drama by the fact that cyclists further ahead are visible as red lights, which can be chased… One of them on this occasion took some catching, which was surprising given the upright, roadster-style riding position and bulky panniers sported by the rider in question.

With a big effort – who says commuting isn’t training? – I got within visual range and was able to identify a youngish, athletic-looking chap on … an electric bike.

Now, the year before last DA was sent for test a neat folding ‘leccy bike. To test the thing, he and I rode over to Kentish Town to visit Rapha, he on the ‘leccy bike, me on a Mezzo folder. It was an interesting ride, not least for the insight it gave into the strengths and weaknesses of electric bikes. Shiny Boy had a clear advantage pulling away from traffic lights and uphill; everywhere else, he was toast.

The reason was obvious; these things are restricted by law and can only be power-assisted up to 15mph. Go any faster than that and the electric assistance is cut, leaving the rider pedalling unassisted a 45kg behemoth. On a climb, the assisted bike will still go 15mph with a combination of pedalling and power; if that’s enough to outpace the unassisted bike, away you go. Away from the lights, the combination of pedalling and power makes them pretty nippy – but only up to the magic 15mph.

In the pub earlier this year, however, I found myself talking to someone who, judging by his claims, might be a leading light in the – er- underground scene devoted to “uncorking” electric bikes. I knew it was possible; the latest employ a programmable controller that can be used to raise the speed at which assistance is switched off.

Of course, the faster the bike will go with electric assistance, the more power it takes and the shorter the battery life, but this seemed to my advisor a small price to pay for the potential to go at – and my memory may be playing tricks – “over 40mph”.

That’s a bit faster than matey was going along the Clapham Road – or I wouldn’t have caught him – and maybe he wasn’t a part of this “scene”. But it was pretty disconcerting to see a big old trawler hooning along at 25mph, and not in an impressive way. Unless it hadn’t been “boosted” and the rider was simply pedalling it unassisted…