Bicycle Mechanics - When is it time for new chain rings and cassette?

I have about 14,000 miles on my Shimano 105 chainrings and cassette. How can I tell when it is time to get new ones? What are the visual signs and what are the indications from bike performance?

Thanks.

Rich

If they really need replacement, a new chain will jump off when you accelerate! Look at the teeth and gaps between them. If the teeth are significantly shortened, and the gaps look ovalized, they're probably due for replacement. At 14,000 miles, you're certainly getting close.

If you replace the chain more often, the rings and cassette will last much longer. However, with 14,00 miles, just replacing the chain will cause more problems because it won't match the teeth anymore. I agree with roadbuzz, sounds about time. The sweet sound of new chain whirring on the new cogs is worth it alone!
So, when you do end up getting new rings/cassette/chain don't forget to replace the chain more often and you will get more life out of the rest of it!

When there are no longer any flat spots on the teeth of you cogs or chainrings. The teeth all come to a point, and resemble a sharks tooth!

At that point, they're toast!

If you've gone 14,000 w/o a change, you've gotten your money out of them!

L8R

Kind of off subject -

How often should I be replacing my chain. (105 Road Bike)

Thanks

For optimal performance I think it is every 3,000 miles. There is a chain stretch tool that will tell you more accurately. When the chain stretches to about 3-5mm (for 6? links) you replace it. I don't know the correct numbers, but that cheap little tool will tell you.

The teeth on my middle chainring are ovalized and sharky. The big and small chainrings are still quite rounded betweenthe teeth and look OK. Should I replace all three or just the middle?


Originally posted by RacerX
If you replace the chain more often, the rings and cassette will last much longer. . . . So, when you do end up getting new rings/cassette/chain don't forget to replace the chain more often and you will get more life out of the rest of it!

Actually, I'm getting close to buying my fifth chain since I got the bike. So that's a new chain every three thousand miles. Should I really be replacing the chain more frequently than that?

Thanks everyone.

Rich

I think I'd at least go ahead and replace the big ring, too. It's during a sprint or beating a car through an intersection that the chain is going to jump. It can only turn out bad.

Replace the middle only and the cassette. If you have problems, than replace the other 2 chainrings. It might save a few bucks that way.

3,000 miles sounds about right for the chain.

I don't know the correct numbers, but that cheap little tool will tell you.
Yes-that would be a ruler....
Chains should be replaced when they elongate by .5%. This works out to just about 1/16" over a foot. 12 links should be exactly 1 foot. Measure from the same edge of pins 12 links apart, under tension (on the bike is easiest).

There is a specific tool that accurately measures chain stretch. It has two pins that fit into the chain and tells you the exact amount of chain stretch down to the mm.
A ruler is so inaccurate because you need to know down to the mm and eyeballing it will only give you the a ballpark so you may end up chainging your chain too early or too late. Not that it's life or death :) it's only a chain but still;)

http://draco.acs.uci.edu/rbfaq/FAQ/8d.2.html

I'm now sure I need a new middle chainring, probably the big one, and maybe the small one.

Now I'm thinking about how to install new chainrings. I have a Shimano RX100 crankset. Will I have to remove the crank arms to remove the old chainrings and install the new? It appears that if I keep the old small chainring, the new middle and large ones can be slipped around the crankarm. Is that correct?

If I have to remove the crankarm, what tools do I need to do it?

Thanks.

Rich