Similarly, steering is a challenge. If you drive a car, and you start to skid, the standard advice is to steer into it, even if that's not the way you actually want to go. If you don't do that, you may wind up swinging the car around so that it's broadside across your lane. On a bike, steering involves leaning as much as turning the handlebars. So, if the wheels are starting to slide to the right, and I lean over to the left, I'm going to wind up flat on my face in the mud. So, you basically have to "suggest" things to the bike, to guide its path rather than forcing your will onto it. More specifically, you can make gentle adjustments in the direction you want to go, but you have to be attuned to the bike and the terrain.
I've found that I'm getting better at this, although the snag is that it's becoming subconscious, so sometimes I can detect a change but I can't isolate/describe it. That happened recently with the Boris bike, and a couple of years ago with my Brompton. There was also another incident with my Brompton a couple of months ago.
I was going downhill, but I was pedalling rather than just coasting. Suddenly the bike "locked": that's the word that instantly popped into my mind, but I couldn't immediately list the clues that had let me to that conclusion. I couldn't pedal, but the bike was still moving. The back wheel was sliding side to side a bit, but it wasn't in a complete skid. Fortunately there wasn't much other traffic around, so I was able to get the bike over to the side of the road, then stop and lift it up onto the pavement to figure out what was going on.
My first guess was that the chain had derailled, but it was still in place on the front/rear sprockets (cog wheels). I then suspected a flat tyre, but that was fine too. I tried lifting up the back wheel and then spinning it by hand, but that didn't work either. I eventually realised what had happened: my pump had fallen off the frame and got stuck in the back wheel.
The rear of the bike normally looks like this:
Once I'd got the pump out of the frame, it looked like this:
It took a fair bit of tugging to get the pump loose; I didn't realise I was pedalling hard enough to crush it so tightly! The wheel seemed fine after that, and I've replaced the pump. Still, it's something to watch out for if you have a pump mounted on the seat stay rather than the seat tube; my Roberts bike had a similar design. Now that I've encountered this issue, hopefully I'll recognise the feeling if it happens again, so I'll be able to identify the problem more quickly.
