After my chain has broken what should I know about buying and maintaining a new chain (apart from lubing it and replacing when it 'stretches')? Do you keep a spare chain, or a spare link?
I have a commuter bike (a Kona Dr Dew) with Shimano dérailleurs.
The first chain was replaced "worn to at least 100%" after the first 6 months/5000 km. The cassette seems OK and not worn. This was the second chain, replaced two months ago. I noticed occasional slipping gears but don't know whether that was the chain, or the indexing of the gear shifter.
The chain (the replacement chain, which broke) is an SRAM PC-951 which Google says is "our most economical chain".
Update - it wasn't the removable SRAM link, it was one of the factory links that broke. Because it had been skipping and the previous chain worn more than 100%, I asked to replace the chain and the cassette (even though he agreed that the cassette didn't look really worn, he said 5000 km is too far for a chain); and got a chain stretch measuring tool, if replacing the chain every 6 months isn't often enough. Anyway it's tight again now. The new chain is a more expensive SRAM PC-991 (which cost more than the new SRAM 950 cassette). The original parts I think were all Shimano.