Is it cost effective to replace the drivetrain on an older mountain bike?

I have at least 5000 miles on my well cared for Cannondale F900. All other components are in excellent shape.

I would appreciate some opinions on whether it makes sense to replace the drive train, or if I will get better VALUE buying a comparable new bike.

EDIT: Cables and chain are newer and probably salvageable... so everything else in this case including the derailleur...

I'd replace what you need to in the drivetrain and keep the bike going....as long as you still like the bike and the rest of the components. You can buy a cassette, rings, and a chain for as little as $100 if you shop smart.....$150 to $200 if you buy better parts at normal retail. You can even find package deals with the derailleur, chain, and cassette for good prices online.

If you've ridden that bike very hard or had some tumbling crashes, then you might consider a new bike (or just a frame). Lots of bikes can go forever and never fail, but with hard use and aluminum frames, it makes sense to replace them after several years.....cheap insurance when compared with medical bills. :o)

I think it would actually be just as cost effective to go ahead and look at a new bike. If you're talking about a whole new drivetrain including derailleurs, cassette, chainrings, etc, you will be spending quite a bit of money not only for parts but also have them installed if you don't plan on doing it yourself. I would expect to drop at least a couple hundred dollars by the time it all adds up. If everything still works decently you might want to consider just getting a full drivetrain clean from you local bike shop. This will get all of the dirt and grime out of the drivetrain and almost make it seem new. Should come with adjustments also.

It would be to your advantage to probably just buy the drivetrain. If your bike is well cared for, it really doesn't madder how old it is. And you can get some good drivetrains for cheap

Drivetrain means exactly what to you? Crank, chainrings, cassette, chain, both derailleurs, both shifters, cables?

!

do not know good luck though