ahultin

Just got back from a trip to the LBS to have my rear derailleur adjusted as it was skipping on the 11 tooth rear. They tell me my chain is at .9% stretch and near end of life. The chain is a whippermann connex and was put on new May 12. I will have to go though mileage but would estimate about 1500 on the chain. Is this normal wear or should I go to a different chain? This is my fourth chain on this bike, previous two where ultegra chains that actually broke (put a new cassette with this one)

JavaMan

Not sure what .9% stretch means. The usual way to determine when to replace a chain is to measure 12 links with the chain under slight tension. It should be 12 inches exactly. If longer by 1/16 inch, replace it. But that works out to .52%.

A "stretch" of .9% would be .108 inch, a hell-of-a-lot for 1500 miles. BTW, I get about 5,000 miles out of an Ultegra chain (riding on the road in mostly dry weather, lubing every 100 miles).

Mr. Beanz

This link explains the 1% stuff

https://pardo.net/bike/pic/fail-004/000.html

park tool that checks this stuff.

gauge and video

https://www.parktool.com/product/chain-checker-cc-2

pdlamb

The answer to how long a chain will last is, "It depends." Some people get ungodly long life, some people kill a chain in 500 miles (usually riding in a lot of mud). 1,500 isn't unreasonably low, but you might want to check with a ruler. I'd suggest you replace it soon, so your cassette doesn't need to be replaced as well.

For reference, mine are usually good for 2,000-2,500 miles on hilly roads with occasional rain.

A bike chain is a consumable, like tires, so I like to buy cheap ones.

Seattle Forrest

1,500 miles seems a little young, but not that much. I tend to get 2,000 to 2,500 miles out of a chain.

I'd replace it if there's any question, because chains are less expensive than cassettes (if you run Ultegra) and, in the long term, chain rings.

CliftonGK1

On my commuter bike I get insane life out of a chain, but it's an 1/8" singlespeed drivetrain. Built for a beatdown.

My CX bike is the same setup, but due to CX race conditions (lots of stompy sprints, sand, mud, crashing in a big heap of bicycles) the race chain will last a single season.

Nightshade

Any chain will last "almost forever" if it is enclosed in an oil bath chain guard.

That said, just enclosing the chain will double it's useful life.

pbd

What lubrication are you using? Applying regularly? Do you mash, or spin? Climb hills or do much out-of-saddle work? Ride in bad conditions like wet/mud? All these things affect chain life.

1500 isn't shockingly low, but it's not great either. My current SRAM chain is it 1473 miles, and is somewhere less than .75% "stretched". I don't know the exact number, because I use this little chain checker that is simply a pass/fail test at .75%. But I'm definitely a spinner, not a masher, this bike has never even seen rain, much less ridden in it, and never any other bad conditions. I'm also pretty religious about cleaning and lubricating.




If the checker fits between links then the "stretch" is more than .75%, if it doesn't go in then it is less than .75%, and that's the threshold at which I replace the chain.

Seattle Forrest

Why do you use a chain checker tool over a ruler, pbd? Convenience, or something else?

pbd

It's convenient, very quick. Literally just put it on, there's no reading it or anything. Hook it on one pin, if it falls in then it's time to change, if it doesn't fall in then it's good to go. Takes literally 5 seconds, no tape measure required, I keep the little checker next to the bottle of chain lube with all the other frequently-used tools.

A tape measure works just as well, but the little checker tool is just so darn convenient.

ahultin

I lube and clean it a least weekly. Lube with Tri-flow.

I do ride in the rain on occasion which with this particular chain has been once (last sunday) But I also ride fairly early and near the coast so there is quite a bit of moisture (marine layer etc)

I believe I am considered a masher (average cadence is 75-85)

This chains life has been about 50% of the mileage climbs

Pinyon

I use a ruler.

Be careful if you have a rear derailure. I keep my chain so well-lubed and clean, that if I don't watch it, by the time I notice that it needs changing, I also need to replace the rear cassette. That is an extra $25 - $45, depending on how many gears you have in back (7-8 speed cassettes are cheaper than 9-10 speed ones here).

Drew Eckhardt 

Measure it yourself with a ruler.

Put some tension on the chain, measure between pins that should be 12" across, and don't worry unless you get to 12 1/16" (0.5%) because the pitch change causes the chain to ride higher up on the cogs + rings and wears them out too.

Your shop could be using a chain checker which is both convenient and increases chain sales - most (Shimano's measures pitch, but nearly all the rest don't) measure the total between rollers which includes designed-in clearances (even new chains are not 0%) and roller wear which won't affect pitch.

Replace at 0.5% or when you don't like how crisp the chain shifts.

I have 3500 miles on my current Campagnolo Record C9 chain and can't yet measure 1/32" of wear (0.26%) although shifting has degraded some from side-wear. Other lesser chains would be shot at this point.

Did the shop install the chains? They may have tried to rivet them instead of using the special non-reusable pins.

Drew Eckhardt 

Since the checker goes between rollers it's measuring the total of "stretch" (changes pitch and wears out cogs) + the manufacturer's roller size (may be > 0% on a brand new chain and has no impact) manufactured clearances (same) + roller wear (no impact)

The two ways to be accurate are

1) With a Shimano's TL-CN41 tool ($60-$80 depending on source)
2) With a ruler (I doubt I paid $6 for my nice stainless steel ruler with convenient 1/32" marks)

https://pardo.net/bike/pic/fail-004/000.html

https://www.greentirebikes.com/62634.html

ahultin

Finally figured out the problem. Checked the chain with a ruler (several actually) and the chain doesn't even show 1/32 wear. Since the problem was skipping on the 11 tooth I have just been staying out of it.
Had a little time tonight to research and determined that the connex link installed with the chain (by the LBS) was installed backwards!
https://www.velimpex.com/wippermann/connex-link.htm
Cleaned it, lubed it and reinstalled the connex link right and now all is right and well with the world

JusticeZero

Yeah, '.9%' seemed like a pretty odd number, and then you mentioned that they helpfully offered to sell you a new chain and shop time.. Time for a new LBS.