When to replace components??

I bought a bike with ultegra in august of 2000. in march of 2003, the bike had about 12000 miles on all its original equipment except chain and tires. I replaced the chain every 2500 miles+/-. at 12000 miles, I replaced the chainings and cassette and had the hubs overhauled (admittedly, the cones were pitted fairly badly). the shifters, fd, and rd I replaced about a month ago, all having 17000+ miles...everything still worked reliably, I just upgraded.

replacement should be when you experience trouble or wear is obvious. I replace chains, and clean my entire drivetrain, often to prolong cassette and chainring life. you can ride a chain, cassette, and chainring combo a long time and it will still work as everything wears out together. but when you replace the chain, it won't work with the other worn out gear, so the cassette and chainrings will then need replacing...a costly hit all at once. unless there's some sort of problem with your particular components, ultegra will give 2 or 3 times your 5000 miles, if you take care of them.

Quoted post said:

Originally posted by memphiscyclist
I currently have ultegra components which probably have around 5,000 miles on them. Since it's taken me a while to put this many miles on them, it is hard to tell how efficient they are compared to the way they used to be. I suspect they are not nearly as efficient. My question is, how do you know when you need new components? Does your drivetrain spin efficiency degraid as they wear, or is it just the gear switching that is affected? Is there a way to tell just by looking, other than noticing that you have worn down all of your teeth? What about chains? When should they be replaced...when they break?

You could stand to have a maintenance book. Chains need periodic cleaning and relubing,and replacement when they have elongated 1/16" in a foot of chain.New ones measure exactly 12", c-c of pins when tensioned. A too worn chain will trash both cassette and chainrings. The other stuff usually tells you when it's toast,because it quits working and cannot be fixed with simple adjustments. Cables and casing can also have a mal effect on how things work.