seat post stuck

jhamling said:

My seat-post has jammed and I can't move it up or down - luckily its in the right position for normal use but I need to be able to slide it up and down - what's happened to it? Has it been caused by the hot weather?

It happens. It doesn't happen on bikes that receive lots of TLC, but with a little inattention and a touch of bad luck, any bike can start suffering from stuck parts. It could be a number of things, depending on what sort of seatpost and frame you've got, but most likely, you've fallen victim to some seizing. In the future, periodically remove, clean, and regrease the sucker (in case it's something else, though, do some reading... see below. Best to know).

Here; check out Sheldon Brown's site. He's got lots of tips.

Thanks mate,

I thought my bike did get enough TLC, I just didn't realise that the seat-post was classed as a moving part! - will try the link you posted...