GT85 400ml spray £3.69 from Halfords
Miles covered/time: I get through a can every few weeks.
What's good? GT85 is basically like WD-40 but smells nicer.
I use it for everything on my bike, especially cleaning my chain on a daily basis on my biking holiday.
Some people might call that OCD, but I hate the sight of a dirty chain. I use it to clean all of the non-painted areas on my road and race bike and of course it protects and is a water repellent.
It's also used by Virgin Airlines, the MOD, Porsche, BMW and Mercedes.
What's not? It's perfect