GRedner

I waited a bit too long to replace the chain on my commuter, and now both the chain and the cassette are shot. They're not so far gone that I can't ride on them until replacement parts arrive (i.e. no skipping, yet), but the chain-wear gauge does fall rather easily into the gap.

So...question: Do I need to replace my chainrings along with my freewheel? The bike is a double, but I use the big ring almost exclusively.

operator

Yes.

matimeo

I don't know. I've never changed chainrings on a bike unless they were rendered useless by a crash or something. I just upgraded a bike and used an old shimano 105 crankset with chaingrings that were probably 10+ years old and they work just fine with a new cassette and chain. The same is not the case with a worn cassette and a new chain, you get slippage. My experience is that nothing will happen if you stick with the old rings.

notzofast

Chainrings and casette wears down because of the chain. Replace chain, SRAM with EzLink. Then take your chain off every 100 miles or so and wash it well.

It's clean when you feel no sand or dirt inside the chain, when you take it in both your hands and bend it side to side slightly. When dirt you'd feel like there is dirt inside the chain. Clean until it feels like brand new chain. Then lube.


Cross chaining, bad chainline, cheap chainring are also factors.

Wordbiker

In my experience, chainrings wear about two to three times slower than cogs and chains.

The torque load is distributed over a greater number of teeth, and on a double, you are not "shifting through" any chainrings as with a triple. With triples the middle chainring seems to get the most abuse as you can't skip over it to go from large to small, or vice versa.

I'd replace the cassette and chain, then replace the chainrings if necessary.

GRedner

Thanks for the feedback. I'll probably go ahead and replace the chain and cassette, and see how things go.

I will attempt to procure replacement chainrings in the event that they are needed. I need 144mm BCD rings though, which all seem to sell for big $$ (at least, bigger than I want to spend on a commuter bike). Argh.

Wordbiker

Good call.

I can't say you won't need the chainrings. A client and friend of mine that is a high-mileage roadie replaces cassettes and chains together nearly every year, and chains inbetween cassette replacements. He'd never replaced his chainrings and when I recently installed some new Salsa rings, he came back and said his front shifting was better than it'd ever been before, even when new.

At least you can spend some time now to find a deal on the chainrings.

San Rensho 

Chainrings last a long time, especially if you change the chain regularly. Eventually, you will see that the CR teeth look shark-finned, that means they are starting to wear. Sure fire way to determine is to put a new chain on and if you hear noise from the CR, time to replace.

I've had chainrings last 10 years+ with regular riding.

HillRider

No.

Sluggo

I agree. My experience is that chainrings last a very long time.

idoxlr8

Have 100000+ miles on my fleet of bikes, and have never replaced a chainring. I still have Biopace on some of them.

barba

Unless I see that they are obviously worn (shark fin teeth, etc.), I leave them alone.

capwater

+1 on the sharkfin appearance. They do last a long time, but folks that hammer on their rings will wear them out much sooner than a tourer.

ScrubJ

+1 Purchased a 53 tooth Ultegra chainring once thinking I'd need it some day. Many miles later, and I'm still sitting on that ring.

operator

Thanks for missing the point.

How can you make a diagnosis without even seeing the bike? You guys clairvoyant all of a sudden?

supton

What about shifting ramps? Or whatever these are called: I've looked at the Alivio crankset on my bike, and there are these notches running down some of the valleys, in four locations. The notch is flared a bit, presumably to help the chain ride up on upshifts (this is an MTB, so big jumps). The teeth near there look very shark tooth, but the rest just look somewhat worn. I have ridden the bike with a very worn chain in the past, and the current one is worn out also (but not as badly).

Wordbiker

How can you?

All that was related was experience. Chainrings last a lot longer than most people think...apparently including you.

And yes, my telepathetic powers are formidable.

Tapeworm21

Like already said.... you too made a diagnosis as well. A wrong diagnosis, but a diagnosis.

GRedner

I'm not sure why there's attitude seeping in from all corners, but it doesn't help anything.

The chainrings don't look worn. They're only one chain old, so to speak (and the small ring has barely been touched - I may replace it with a bigger one eventually). I did once ride a drivetrain on another bike right into the ground - the jockey wheels were so worn that the tips of what once had been gear teeth were needle-sharp! By comparison, my current commuter is newer-than-new

A tangentially related question - does cross-chaining increase wear on chains/cassettes/rings?

mollusk

Yes, yes, and yes.

ZanesGrandad

There seems to be some debate concerning chain ring replacement. Can anyone post a photograph of what they consider replacement worthy wear or damage? I'm considering replacing my outer ring on my Madone 5.0 commuter (and backup). Having some difficulty finding a replacement. It is a triple crank, 52 tooth. Can it safely be replaced with a 53 tooth ring?

HillRider

A truly worn chainring will have sharply pointed teeth like a crosscut saw and/or heavily shark-fin shaped teeth. The real test is does the chain skip on the chainring under load.

Crank makers typically design their chainrings in pairs so the shifting enhancements (ramps, pins, shaped teeth) line up for best results. Changing to a chainring from a different set will compromise shifting somewhat. So, using a 53T chainring intended for a 39T small ring will not shift as well as the matched 52T that is provided on a triple crank.

FBinNY 

like tires, brake shoes and cables, there's no scheduled replacement involved. Replace as needed. Meaning when the chain slips and won't transmit power, or when teeth break or bend. On a road bike, this may happen at 40-50,000 miles or so. On a mtn bike the granny or middle ring can wear out in less than a year of hard riding.

hueyhoolihan

wait for it....

fietsbob

Steel and 7075t6 aluminum is pretty long wearing .