Upgrade Now Or Replace as Stock Parts Break?

[rtsy]

One of the more common (and temptingly sensible) advise I get on forums like this is "get better components as your current parts break."

My question now is, if you are a typical, responsible rider using a generally well-accepted bike, how long before those stock parts break and in what order?

Specific to my case:

1--I ride my Giant NRS3 ~100km/wk,
2--I am not too adventurous an XC rider (no jarring jumps & falls)
3--Clean my bike decently and take it to the shop for tuning 4-6 times a year.

I like the "upgrade the parts that break" idea but I also don't like to miss out on performance improvements upgrades can bring about.

Aside from deciding when to upgrade, I'm also prioritizing what to do first. Will it be the drivetrain? the suspension? the breaks? etc.?

Any inputs from the more experienced bikers here are much appreciated.

 

[MidBunchLurker]

Generally the first stuff to replace (if you're not waiting for it to break) is those parts where you can score a major weight-saving, or a major performance increase.

Things that are often good candidates for upgrades are:
1. Wheels - depends what your stock wheels are, but a quality set could save up to 500g.
2. Tyres - often stock tyres are the steel-beaded versions. The kevlar-beaded ones are usually about 100g lighter per tyre.
3. Forks - some cheaper stock forks are poor performers. If you ride a lot you'll appreciate better performance here.
4. Some stock seatposts/stems/bars/saddles are quite heavy. You can save a bit of weight be replacing some/all of these.

Keep an eye out for specials on these things and you should be able to upgrade relatively inexpensively