Chain or chainring wear

wavey1000 said:

My boarman fsa crank is making a small wearing noise when I pedal, but only on the larger fron ring. The small ring is fine. I have bought a new chain, but was thinking the large chain ring may need changing as its 4 years old. To be honest so is the chain.

So do u reckon I need a new new chainring or should I try the new chain first?

Are you sure it's not the front derailleur rubbing on the chain?

If the rings and chain are four years old, would it be safe to assume that the cassette is also? If so, even putting a new chain on may not be the end of your problems. New chains do not run well on old worn cassettes. Putting the old chain back on solves the problem temporarily.

Chain checkers are cheap and cheerful but provide no progress between the intervals built in to the checker. The cheapest way to measure a chain for wear is to take it off and measure it. To facilitate this I use magic links rather than rivets to connect the chain. Lay the chain out on newspaper on a flat surface. Pull it taut and then with a metal tape, measure 100 links from pin to pin. A new chain will measure 50" bang on. Yiu will find that your 100 links will be more than that. The chain needs replacing for sure at 0.75% stretch, which is 50-3/8". Scrap it if it measures 50-1/2" (1%) Measuring over 100 links provides good accuracy with basic tools and is easy to do. Take care when measuring and maybe get someone else to hold the idiot end while you concentrate on the other end. To improve accuracy, I don't use the hook end of the tape measure. Instead I line up a major marking (say the 10" one to make the sums easier") with the centre of one of the pins.

A quick play will not put sufficient load on the chain to make it slip. I had a disastrous day out at Cannock because my new chain was slipping on the cassette. It hadn't done so on the street outside my house.