LouiseSJPP

I've usually taken my bike to the bike-shop for maintenance, but given that I have practical skills, this seems a bit silly (currently, I'm rebuilding a Triumph Stag differential...). My sticking point at the moment is that my Canyon Endurace must be coming up for replacement of parts of the transmission chain, but how do I tell which parts? How do I gauge the wear of teeth on the rings and cassette to make the judgement call for which need replacing?

Louise

Iride01 

It's all on you. What make you feel good about it?

I like to wait till something is actually exhibiting a problem before replacing something. Other than maybe the chain, which I'll replace when it measures 1/16 inch off in 12 inches.

If I happen to be changing something that is a lot of trouble to change and other things that aren't worn enough now, but might be later and are easier to get to because of the other work being done, then I change them out.

If I replace a chain and then have problems with chain skip or something that might be wear of the cassette or chain rings, then I replace them when they show that. Those are easy changes on my bikes.

If you choose to do something sooner I don't care. That's your business. But just don't become one of those preaching doom and gloom for all of us that choose to wait. It's not ever the doom and gloom imagined.

urbanknight

I suggest you start by reading some of the articles by the late, great, Sheldon Brown. https://www.sheldonbrown.com/repairs.html
One of the best things about bicycles is how simple they are. You will probably need some special tools, but after that you will be saving a bundle in shop fees.

Andy Somnifac 

Get a chain checker. Use chain checker. Replace chain when checker says the chain is worn.
Cassette will be replaced far less regularly than the chain. How often depends on how often you replace your chain and the environment you ride in.
Chainrings will be replaced even less regularly than that (I've never replaced a small chainring since it never gets used since I live in an incredibly flat area).

Some people do a cassette every 3 chains. Some more. If I replace a chain and find I have issues w/ skipping on the cassette, then I replace the cassette.
Chainrings would likely be on an XX,000 mile rotation. You can look at them and see if they are starting to look like shark's teeth.

If you have trouble shifting that adjusting cable tension won't tune out, it may be time for new cable(s). Sometimes crud gets into the housing that causes friction, at which it's time for new housing.
Friction in the cable causing your brakes to not release fully (assuming you don't have hydro brakes)? Same deal as above.

None of it is rocket science.

HTupolev

Replace the chain when it's elongated too much, which can be measured with a metal ruler.

Replace sprockets when they no longer shift or engage well with a new chain.

shelbyfv

Here is a good chain checker. I like these because they are "go/no go" and I don't have to read small numbers and think about it. Some folks prefer rulers. Replace your chain when it's time. Only replace the cassette if a new chain skips. I like chains with reusable links. There is a tool for those as well.

DaveSSS 

I've never owned or used a chain checker. I precision 12 inch rule can be used to check elongation. Place one end of the rule on the edge of a pin. The pin at the opposite end will be completely covered on a new chain. When that covered pin is half exposed, you have a little over 0.5% elongation. I also use calipers to take a measurement between the rollers, at the outer plates. The shortest measurement will be about 1.200 inch with a new chain. Since roller wear does not affect chain pitch, there is no prescribed limit, but 1.220-1.230 is a lot of wear.

urbanknight

I had a chain checker. The chain would start skipping before it registered anything. Now I use the ruler.

Kimmo

And to make it last, keep your chain clean. Wipe off excess lube several times after lubing - wipe, ride, wipe, ride, wipe.

You should be able to eat off that thing. If it's sticky, it'll pick up dust, which works it's way inside the chain and acts like grinding paste.