A nice post Pat,

and it seems to agree with what I had in mind. Rig is 105. Chain will be replaced every 5000km, cluster 10000km or with chain replacement if required.

From experience from maintaining my old steelo the bottom bracket is the guiding light: if it needs service then retire the bike. You couldn't use this guide in the old days because bottom brackets were high maintenance. Nowadays they need (relatively) little maintenance. Let me know if I'm wrong...