It's a long time ago - I was amused to discover over the summer that I'm a 'veteran' - but I used to do some cycling road racing / time trialing. And the experience still proves useful.
A while back, someone asserted the (somewhat sexist) belief that women get fewer miles per gallon when driving compared with men and saying it was because they use too low a gear when driving. (Americans: most UK cars have a manual transmission, so gear selection is down to the driver.)
Well, most cyclists use too high a gear.
It's much more efficient to have your legs go round and round quickly, pushing against a small resistance, than have them go slowly, pushing against a large one. Racing cyclists have a cadence - the cyclist version of revolutions per minute - of 120 or more. Slow ones do about 60.
A rule of thumb is that if your knees ache more than your legs after a ride, then you used too high a gear.
Apart from reducing knee ache, why is this important? It means you can accelerate quicker for one thing.
There are about ten traffic lights at the start of my route home that are timed so that if I'm stopped by one, I should be able to cross the next set, but be stopped by the one after that.
One evening, there was another cyclist going the same way.
As usually happens between cyclists of roughly the same speed, there was an element of 'I'm faster than you' between us.
It's a bit pathetic, but fun. And the competition gets you home quicker.
We had a more or less identical cruising speed, but what was happening was that I'd get to a set of lights on red and stop (this will shock some London cyclists, but they're busy crossroads and you'd be silly to ignore these red lights).
Then as the lights were changing, he'd arrive at them and sail past me while I accelerated up to our mutual cruising speed.
At the next lights, as he was ahead, he'd be caught and stop and it'd be me who would go past. Because he was using too high a gear when moving off, he'd accelerate more slowly, but the end result would be the same: back to me getting stopped and him going by.
Up until the one before the bridge across the Thames we were both going to cross.
This time, although it changed to green before I arrived, I was the one already at speed. So there he was, moving off slowly, up a rise = even more hard work. He really really needed to be in a lower gear.
Whoosh, there goes Ian, already going faster than he is up this small hill of a bridge, legs moving around, and then... I change up a gear, so I'm going even faster.
If you lose "the wheel" in front, ie you're not close behind someone, you have to do extra work to catch up. When someone goes straight past you like this, especially on a hill, there is a huge temptation to say 'sod it, I'll go my own pace'.
It's how Lance Armstrong wins the Tour de France. He's a very very good time trialist, but what destroys the confidence of his rivals is that he can just leave them for dead up the steep slopes of the mountain stages.
And this is what happened here - by the time I was going over the top, he had hardly moved and he was still off back in the distance at the last few sets of lights of this section... Result! :)
There were some kids on bikes doing a slalom course along the road. They had some markers down on the middle of the (very quiet) road and were seeing who could weave along them the quickest.
In out in out in out.
Because they were very low markers (or it would be dangerous in case a car came along) it was possible to give them a demonstration of how to do it properly :)
If you go quickly, you can't turn corners very well. It's why F1 cars have brakes - to enable them to go around the corners, rather than straight off the track.
So if you keep your body moving in a straight line, you can go much quicker - your body is much heavier than the bike.
Whoosh. Up to speed, I get out of the saddle. Here come the markers and my body goes over them, while I move the bike from side to side. Legal - they all agreed I didn't miss one - but complete destruction of their fastest time.
There was a group of about a dozen teenage boys on bikes in the road, cycling slowly and chatting.
Whoosh. I went straight past them. They were not amused.
I heard the word 'batty' (Jamaican slang for 'bottom', hence the homophobic phrase 'batty man') and a quick look back revealled they were giving chase.
I wasn't scared - the day I can't outrun someone on a cheap (= heavy) mountain or BMX bike, on roads I know, given a small head start, I'll stop cycling.
But it did add a little extra push.
A couple of fast turns around corners - once you're out of sight, there's a temptation for those behind to slow down - and I have a quick look back.
Yep, they're all strung out, with only two visible and a big gap between them. Even if they could catch up, one-on-one is a much more risky proposition for the bad guys than twelve-on-one. There're no friends to be macho in front of, and you could get hurt.
A couple more turns and they've given up. Ha.
Part of me was disappointed as it meant they didn't get a lesson in how to climb a hill.
The rest of me was more sensible... and I'm somewhat glad that I haven't seen them since.