Riverman said:btw in the muppet video magmatom, you don't look over your shoulder that much. It's just something I've noticed watching your other videos.
As I've said previously, if I notice a problem behind me I will look behind more. If I don't then I look behind less. However, the frequency varies depending on traffic conditions, location, speed etc. On the quiet back roads that I cycle on, I look behind less. In heavy traffic I probably look behind more.