Commuting is a completely different animal to road cycling, in my opinion.

It is very much utility cycling, but the interesting thing is that commuters over a year probably ride their bikes much further than the normal sports cyclist... they ride everyday... in fact, twice a day.

And commuting cyclists get to know their bikes extremely well. The bikes usually are built for reliability. The riders can tolerate little changes to the point of not noticing them. So, for me for example, I would think nothing of riding a commuter bike until the chain, cogset and chainrings all needed changing because they were worn out. Heck, I've ridden a commuter with a broken spoke (actually, removed) for several months because I knew the bike could handle it.

The toughest little bike I had for this purpose was an Australian Apollo MTB with Hi-Ten steel frame and seven-speed freewheel cassette. It was retrieved from the local rubbish dump, and as I said in a previous post, it did over 6,000km of hard commuting. The weakness was in its wheels, which were single-wall, cheap ones, but even so, I only had to go to the dump and get another one when either gave up. The chain was lubed, but not routinely cleaned (only after rain), with bog-standard motor oil, and it lasted a long, long time.

My other long-term commuter was my touring and randonneuring bike, but the roads on my commutes then were all sealed, and as also mentioned above, it got a good once-over prior to major events (and tours). It, in fact, was the reason why the old Apollo took over the commuting gig -- I didn't want to destroy the Velocity Aerohead rims on the tourer on the rough gravel road.