This seems like a bit of silly question, but in 25 years mountain biking I’ve never had a single freewheel problem, soÖ when they play-up or fail do they fail to engage or fail to disengage?

Also, is it likely that the freewheel might intermittently fail and give a skipping/drive failure moment?

And finally (sorry) is it possible that this is all a result of keeping the bike in a flippin’ freezing shed and it never having an opportunity to thaw?

Basically I’ve got drive skipping problems and I don’t think its the usual suspects, because rings cassette and chain are all new and correctly fitted/adjusted. I think.

It’s possible for them to fail in all three of the manners that you’ve suggested, it’s also possible for water to find it’s way into a poorly sealed freehub and freeze up too.Shimano, and other similar types, usually give warning of impending failure with a rumbling sound when freewheeling, usually a fair while before giving up the ghost.
If it’s a Shimano item then you may want to buy a complete hub, rob the bits you want(and maybe upgrade to a better sealed type if you have a lower end model)and sell on the skewer.

My XT freewheel skipped like hell last night, would only engage in one position per rev. Today it was fine. Last night was -5 and had been below zero all day, today was 3 degrees.
A google search told me that it was the lube in the freehub becoming sticky with low temps and the springs not being able to push the pawl out. Sound plausible to me.

Thanks, c and c-d.

Cold seems likely culprit. Needless to say its never been attended to in any way – being Shimano I naturally expect it to work faultlessly forever!

Cheers

It’s been known that peeing on it will give it just the heat it needs to free off. Oh yes !