When to replace chain rings?

[Rideuphill]

I have over 30,000km on my sram red drive chain. I'm replacing a few items but the front end shifting seems to work fine. Sram red rings are crazy expensive so I dont want to replace them until needed.

When should one replace the rings? Can you tell by looking at them? Run them until they dont shift well? Can you use the km's as a reference?

Thanks for any help!

Link to pic below (not allowed to upload pic's anymore?)

https://docs.google.com/file/d/0B1KAmSlJbW-qYk9ENWktR1BwR3c/edit?usp=sharing

[quattrings]

If they are sharktoothed, I would replace them.
I'm always one to leave them on as long as possible as well but last time I replaced my Mtb drivetrain and skipped the chainrings and it wrecked the chain and casette in no time.

I'd say as a guideline:
2-3 chains per casette, 2-3 casettes per chainring.
Depending on the maintenance, your strength and style (the spinners amongst us tend to be kinder on the drivetrain stuff), and their purpose.

PS: don't forget the jockey wheels
Red is insanely expensive in this department too... 100 bucks for some pulley wheels, really?????
Good thing they aren't a proprietary part... oh wait...

[eric]

Pull up on a pin on the chain, where it wraps around the sprocket. If you can see half the tooth the sprocket is worn.

Or if it shifts poorly or makes excessive noise with a new chain.

Sram Force rings shift about as well as pre-2012 Red in my experience and cost less. They're lighter too.

[austke]

Quattrings is right, one worn part on your drivetrain will tend to prematurely wear the rest of your drive train.

[stella-azzurra]

I've never needed to replace chain rings.

[thisisatest]

Your rings look fine. if you know someone with new rings of the same type, you can compare them. Width changes. Worn chains wear out the gears, if you are good with replacing chains, rings will last a VERY long time. Mtb rings don't last anywhere near as long as road rings.

[prendrefeu]

Good thing they aren't a proprietary part... oh wait...

They aren't. Research does wonders.

[Frankie - B]

Jumping on the Sram pulley wheel discussion. I have replaced Sram red pulley wheels with Cf and alloy ones. Both lasted less km then the original Sram wheels. you can choose between either Rival/Force and Red Wheels. The latter have ceramic bearings in stead of steel ones. The complete groupset is expensive, don't go downgrading it with cheaper aftermarket wheels.

[DMF]

Aren't the RED pulleys made by Ceramic Speed? i.e serious high-end stuff and not just any generic chinese ceramic bearings (i.e KCNC, etc).

i

[sungod]

the red pulleys have 'blackbox' bearings, not sure who makes them but the seals are pretty draggy, when the wheels got worn i replaced them with ceramic speed ones, seem much better, still spinning freely after lots of wet dirty miles

[Mr.Gib]

Chainring life depends so much on riding situation.

I weigh close too 200 lb and ride in an area with some short but very steep hills 15 - 20%. I clean and lube almost every ride and if I am lucky I can get 10,000 km out of Sram rings. Shimano last longer.

I get about 2000, maybe 2500 km out of a chain. (I use Sram 1091R on my Sram equipped bikes and 7901 on the Shimano equipped bikes). Again Shimano lasts a bit longer. No idea on cassettes as I am always juggling them around.

If I hear any noise from the drive train I change the chain immediately. If that does not result in perfection than the cassette goes also. With rings I look for the shark tooth effect. Slightest hint and goodbye rings. I once had chain suck before I could notice the shark tooth effect.

[quattrings]

I thought replacing sram's pulleys for an aftermarket alternative resulted in play of one of the pulleys (lower?). Is this not true?

I'm not really an sram kinda guy. only have it on the TT bike as it looked better than Shimano and was cheaper than Campa, have to say on this build it works great though. Would never put it on a roadbike cause I don't like Doubletap.
On the MTB Sram came as standard but I feel Shimano would have been an upgrade.

[sawyer]

Strange - I never get the sharktoothing. I clean the bike whenever it is dirty, ride a pretty clean chain, and rarely ride in rain.

Oldest chainrings in service are 6 years and I'd estimate about 30,000km old

[sawyer]

To take this off topic since some of you have mentioned. How often do you replace your pulleys? I have about 10,000 on my current ones and they seem fine.

On said bike above (6 years, 30-40k kms) ... I put Ceramic Speed pulleys on at the outset and they have been there ever since.

Just cleaned once in a while.

Bike very rarely ridden in wet.

Still spin like roulette wheels!