How long should components last

Dave B wrote:
Hi folks,

I have been commuting on my bike since late June this year (a miserly
4.5 miles each way).

I had the misfortune of a broken spoke recently that forced me to pop
into the LBS. Whilst chatting with one of the bike gurus (who'd just
managed to save my wheel from buckle hell) we got talking about my bike
usage and components.

I've done about 700 miles in total (yes I've had some days off and
driven a few times :-)) and he suggested that depending on how much
washing and lubrication I was doing I should expect between 900 and 1200
miles out of most of the drivechain (i.e. derailleurs, chain, sprockets
etc). Does this sound about right?

If so (and my maintenence schedule suggests it will be closer to 900
than 1200!) I will have to budget for some purchases in the new year!

Dave

Oh and my cycling is mainly on roads with a little bit on a gritty canal
path.

Dave