My bike is mostly made up of carbon fiber and aluminum - never head anything rust, despite having to leave it outside daily for over a year (while at work). Before this bike, the commuter was titanium - also good. I have had very few repair issues. I also do very little work on my own bike, aside from flat repair, tire replacement, brake adjustments and lubing the chain... I usually do bring it to the shop 1-2x year for a general check-up or for specific issues + tune up... Mainly, this is because I am not very mechanically-inclined. But, I also think it is good to periodically get someone else's opinion on the state of your bike. I had always thought I did a good job of keeping the chain lubed, but the last time I brought it to the shop, the mechanic said my chain was unusually dry...