Why do chains get stiff links?

Ruined my cx race today. 10 yards from the start and chain starts jumping. Get off, find link has gone solid, couldn’t move it at all. Chain is still straight, didn’t even get to change gear before it went so can’t blame that. Grrrrr!
Doesn’t help that I didn’t get to use up my caffiene dose, so eyes are on stalks at the mo too.

Corrosion and lack of maintenance.

Free it up by using the chaintool from the back i.e. if you used a tool to push in a connecting pin, a light push from the opposite direction frees it up.

you can you the chain tool method as that works but the first way i was taught to do it which works and doesn’t require fishing in your bag for a tool was to push against the link from the side with your thumbs one way and then the next

10 yards from the start and chain starts jumping.

Sounds like a twisted link due to ham-fisted gearchanging, learn how to change gear properly ie not under full load 🙄
Was the bike in the correct gear at the start (actually in the correct gear and not just the correct gear selected).

It’s the temperature.

The cold water from riding can cause slightly stiff links to sieze up; I’ve had it a couple of times; chain working perfectly in the house, then gets splashed with water or even just ridden in the freezing cold and it jams up.

Dibbs

As I said “Chain is still straight, didn’t even get to change gear before it went”
and I was in the right gear.

Oh well, first time it’s happened in 15 years of ‘cross racing, just hate having to pack.