A very quick post about cycling, for a change.
I was discussing mileage records on twitter, and mentioned that one of the reasons I track my mileage is to rotate chains. This is a method of spreading chain and cassette wear over a number of chains, and I first saw it mentioned in Cycling Plus;
To maximise cassette and chain life, buy three new chains when fitting a new cassette. After 500 miles replace the first chain with the second. After a further 500 miles replace the second with the third and continue to rotate the chains every 500 miles.If you've got an aluminium cassette instead, reduce the distance between rotations to 250 miles.
I change my chains about every 300 miles, largely because, on the commuter, that equates to fortnightly. (The routine being to wash the bike, and change the chain at the weekend - it's easier to clean the bike without the chain on too, on the drivetrain side).
Note that it's just the same three chains being rotated - you don't have to buy a new chain for every change!
I use KMC X9.93 chains - as I said when I was first experimenting with this;
I'm using £10 KMC X9 93 chains, so assuming I go for £30 cassettes (Ultegra, at current CRC prices), the rotation method only has to make the cassette last twice as long to have paid for itself (excluding the possibility of chain ring replacement, which I would guesstimate at £36ish (Tiagra level triple) to £55 (Ultegra level).
The key is to make the change easy, and be organised - I use takeaway food tubs to store the chains (marked LHT (Long Haul Trucker) Chain 1, 2 and 3 for the commuter) and the KMC quicklinks make the chain change easy.
It's not something that's worth doing on 5 & 6 speed systems, in my experience, because they seem to last forever, but on 9 speed and above, you'll get a lot more out of your cassette by doing this.