How can you skid / How to do skids / skidding

What do you mean? That they didn't fade to amber like normal? You're going fast downhill on a busy road which is dangerous at the best of times, with no front brake and the lights changing take you by surprise. It's not your chain line that needs working on.

Especially in the current weather conditions. I find that skidding makes worryingly little difference to my speed on damp roads, even with bum firmly on the saddle. Still too lazy to fit a brake and too stupid to ride slowly though. Although there are no hills on my commute.