datlas 

I noticed that my chain was slipping when on an easy gear (small front chainring and larger cog in back) but only under load, like starting from a stop or standing up on a hill and pushing hard.

After a few trial/error fixes, I believe the problem is a worn front (34T) chainring. The drivetrain is Ultegra 6700 and the chainring had no visible obvious signs of wear. However it does have about 30-35K miles on it. A new chainring has solved the problem. The larger chainring works fine and hypothetically should last longer, although I will be vigilant to watch for problems there too.

What lifespan have you experienced from your front chainring(s)?

GlennR

I have 26,000 miles on Sram Red and so far so good. no problem yet, But I got a killer deal on new chainrings, chain and cassette for the future.I do clean my drivetrain once a week and also replace the chain when worn so i'm not surprised by it being in good condition.

Question: Do yo ride in the small ring more than the large?

datlas 

I would estimate I am about 50-50 between small-big.

cxwrench

How much do you weigh? How much climbing do you do? How clean/lubed do you keep your drivetrain? It's a very hard question to answer. There is no single right answer.

datlas 

I weigh 140-145. LOTS of climbing. Typical rides have 100 feet/mile elevation. Slightly lazy with chain lube but lube after any wet ride or when chain gets dry. Chain gets replaced every 3500 miles or so.

Given the number of miles on the chainring I am not shocked that it wore, but it’s a first for me.

cxwrench

Now you know...replace chains more often and your (no need to say front...they're the only chainrings on your bike) chainrings will last much longer. I can't remember the last time I wore one out.

Reflector Guy

I wore out the large chainring on my old Sears bike listed in my profile. Just like the OP; chain would jump ahead when pedalling hard. It was OK if I was just taking it real easy, but eventually I'd come to a hill, or I'd have to get across a street quickly.... A real momentum killer.

Zaskar

I wore out a Dura-Ace 50t chain ring a couple years ago... that was painful. I think I had about 20,000 miles on it.

I weigh 175 and I'd estimate I'm in the big ring 95-98% of the time. Thinking about the time spent in the big ring was the impetus for two things...
- Switched to a 52/36 crank from the previous 50/34 crank
- Built a 1x road bike

crowbike

I've got 50,000+ on my Ultegra chain rings and no plans to replace anytime soon. Probably 70% of the time in the 39t ring. I am diligent about chain maintenance and replacement.

noodle soup

99.9% of my miles are in the big ring, and my current chainring has a little over 35k miles. Dura-Ace chainrings are a little spendy, so I keep them until they won't allow cross-chaining.

Beach Bob

30,000 km on Dura Ace 9000 rings, generally pretty well maintained and cleaned. They seemed fine until a new cassette and chain was intalled and then their wear became apparante (chain suck up the ring under load)

popeye

In my experience 40-50K. Less if you run the chains too long. I had a cassette that skipped with a new chain which clears up in a week or so I decided to just run out the cassette as it was toast anyway. Ran it long time but it turned out to be a bad decision as it took out the chainring. I didn't think you could have skipping on the big ring but you can.

vtje

Getting about 25k on a big chainring, never had to replace a small one though.

Litespud

I put on a new cassette and set of 3 chains every 12-14k miles. if either of the chainrings starts making noise with a new chain, I replace the chainring, even if there's no obvious "hooking" of the teeth.. I think I've replaced the small (39) ring once and the large ring (50 or 51) twice in ~60k miles. Given that I spend ~75% of the time on the big ring, this is reasonable - so we're looking at 30-40k for a small ring, 25-30k for a big ring

smashndash

So what are people's metrics for "wear out"? Your chainrings would have to get incredibly worn to start skipping, considering the number of teeth each ring has, and the fact that the chain wraps around half the ring.

Does nobody replace their rings once they get worn enough to cause inefficiency or accelerated chainwear? Is that not an issue?

EDIT: Seems like Litespud does this

cxwrench

Chains cause chainring (and cog) wear, not the other way around.

datlas 

You would think so. My front chainring did not look visibly worn. But it was skipping under load. Skipping under load with a new chain is a good enough metric for “worn” IMO, but I am willing to hear other opinions.

Theseus

Newbie in the Forums. Need some advice as per my title. I have a vintage (late 80's) road bike with Sugino steel 52-40t rings and cranks. BB is JIS square taper. I am 65 and want to lower the gearing. Running 6-sp 14-28 freewheel in the rear and prefer to keep it. Pondering if it makes good sense to buy a new, lighter crankset (possibly HT2)
or replace the chainrings - Gebhardt 44-33t for $78 all in.
Most advertised JIS sq taper cranksets are designated as 10/11 speed and specify short spindle lengths compared to mine (est.116mm) which raises chain compatibility and chainline concerns. Any thoughts?

datlas 

You will get a better reply in C&V forum. I suspect you can't get smaller chainrings than you have if you keep the crank due to BCD (diameter of crank bolts). You could get a newfangled modern crank but may need to get a new BB to go with it. Lots of options and much depends on your budget.