4K miles on my 105 11 speed chain.

Shop sez i need to replace.

What happens if i don't ?

1. I agree it's time to replace
2. It will continue to work ok for another few thousand miles but your cassette and chainrings will start to wear prematurely. Chains are much cheaper to replace than gears.
3. Eventually it will start to skip in the back, but by then it's too late and you will need a new cassette.
4. DIY if possible. It's a good skill to have and a chain pin tool is not terribly expensive.

/thread

Hey thanks, i'll get that taken care of.

Changing the chain in time means new chain every 2 to 4 k miles. If doing that (changing before it's too worn, too "stretched"), one cassette will last up to 3 chains (changed that way) without skipping. 4th chain will probably skip on the old cassette, so the minimum is one cassette every 3 new chains if changed in time.

Front chainrings will last a bit longer. Steel ones almost forever while modern aluminium ones probably about 9 to 12 chains (if changed in time), that is about 3 to 4 cassettes.

Method a)
That would be rougly one new chain every 3 k miles.
One new cassette every 9 k miles
Mostly used chainring every 30 k miles.


Method b)
The alternative is riding one chain until it starts slipping or until it breaks. That would mean some 10 to 20 k miles, but then having to change all the chainrings (front and rear).


Method b is cheaper in the long run for most drivetrains, but a worn chain will shift gears less crisply, so that can be a bother. Another worry is a very worn chain is more likely to break - not a nice experience if pedalling hard - usually happens then.

Awesome thank you ... !

I find that I get far more miles than that out of my cassettes(20-25k miles) and chainrings(40-45k miles). My small chainring might last a lifetime. In this part of AZ it goes months without ever seeing use.

That is great mileage IMO. Just curious: is your riding mostly in dry weather, or does that include rain (perhaps winter as well)?

I hardly get more than 3k miles out of a chain, but I ride in rain regularly, plus sand and dust are not too uncommon.

It's nearly all dry weather. I don't avoid riding in the rain, but we rarely get any in the Phoenix area.

The big ring starts showing wear around 30k miles, but doesn't cause any issues until about 50k miles. I have 22k miles on a 6800 50t ring, and it looks like new still.

I've also noticed that 6800 chains last a little longer than 10spd Shimano chains, but that could be due to maintenance. I used to thoroughly clean the chain every couple weeks. Now I just add lube as needed(and wipe off), and thoroughly clean the chain at about 2200 miles. It seems to work well, but it's hard to look at the chain sometimes.

Lifespan of chain/cassette/chainrings is variable and depends on conditions and chain maintenance.

Just like in life - there are no absolutes when it comes to bicycling.

Saying that a chain lasts for a specific amount of time is simply wrong - in my opinion at least and in my experience.

Too many factors go into the lifespan of any component. Things like riding style (masher or a spinner)...maintenance, riding conditions, how you use the equipment etc etc etc.

I've gotten 17,000 miles out of a chain and cassette, but I regularly spin high rpms, thoroughly clean and maintain the drivetrain, never ride in wet conditions and back off pedal pressure for every shift (I never shift out of the saddle or when applying heavy pressure). I've got the original SRAM Rival chainrings at 31,300 miles on my Lynskey and they shift perfectly every time and show little signs of wear.

Scroll down to "measuring chain wear" on this webpage: https://www.sheldonbrown.com/chains.html

Basically if you take a ruler and measure from pin to pin over 12 links, a new chain should measure exactly 12 inches. Once the chain wears to measuring over 12 1/16 inch over those 12 links, it's worn enough to start accelerating the wear to your cogs and is a good candidate to be replaced. If it measures 12 1/8 inch, then you might've worn down some cogs too and definitely should replace the chain.

As noted, riding style and conditions are more important contributors to chain wear than simple miles ridden. I have chains that are around 5k to 6k miles old that are still in good shape and in service.

Looking in awe at all the stated mileages. My chain is giving me a nasty judging look.

I just wipe and oil the chain about every 100-200 kilometres (roughly 100 miles), depending on the amount of rain and dust. Lots of it where I ride so I hate removing and washing my chain every week or two - bike is my main transport, used every day of the year. Good chains last up to 3000 miles, while the cheap ones go in about 1000 kilometres - measured by a ruler for 0.5% "stretch".

I use 8 "speed" chains (6 to 8), so they are rather cheap. It seams to me it would be a lot more hassle and expense to clean the thoroughly chain often enough for it to last longer. I'm also sceptical on how much more miles I would get.

changing a chain before it skips is a waste of time and money IME. like changing a light bulb before it burns out.

if you want longevity, keep it clean.

It's your extra money spent on a new cassette and or chain rings if you leave your chains on until they actually skip.

And although unlikely, if you ever have a chain breakage, if it's been on the bike for donkey's years, you will have to buy a new cassette also cuz the new chain will skip on your worn cassette-which will cost x amount depending on the cassette, and from a tourers perspective, might not be available when the broken chain scenario happens.

You pays yous money and take yous chances.

I stopped tracking mileage when my last speedometer/odometer broke down after a heavy downpoor I rode in. After several years. That was a 3x8 drivetrain. Experimented before with a 3x6 drivetrain. I also fix bikes for friends and acquaintances and work part time in a LBS. My calculations are mostly based on cheaper drivetrains For those: if you want minimal investment of both time and money, it is cheaper to use one chain until it starts skipping. Yes it does require a new cassette, sometimes even a new set of chainrings - but it is still cheaper than changing chains regularly. The price paid is less crisp shifting and a higher risk of chain breaking. So it is out of the question for riding with lots of climbs. But for flat land riding - it is both quite safe, convenient and it is cheaper. Not sure about highly priced aluminium front chainrings (and cranksets). Haven't done any math or testing on those.

I love riding in the mountains and prefer crisp shifting to saving a few $, so I change my chains regularly when worn. But I understand houeyhoolihan's logic - it can make sense for some people, like I explained.

I'm not sure where you came up with that. That would mean I have to buy a new chain every 12-20 weeks. That ain't happening. My chains last many times longer than 4K miles. And before I buy a new chain I inspect the cassette with a magnifying glass. The teeth are almost never worn. A cassette will last me a couple of years, and I ride almost everyday in all weather. Chainrings aren't even on the radar. Just keep everything cleaned and lubed.

If a shop told the OP he needs a new chain and they didn't even inspect it or check the stretch then they're just trying to get his money.

I find that the old chain and cassette skipping due to wear is not as common as skipping after installing a NEW chain on an OLD cassette. So even if you changed out a chain before skipping started with it, you may be surprised to find that you can't use the new one until you also get a new cassette. Occasional measurement is much more reliable for sussing out a worn chain than going by mileage. Despite its well documented shortcomings the Park Chain Wear Indicator, Chain Wear Indicator - Park Tool, is a useful little tool that does the job, albeit a bit conservatively.

I use SRAM Red cassettes which are very pricey, so it is worthwhile to me to waste a few miles of chain life in order to protect the cassette. For that reason I go by the lower wear indicator on the Park tool when checking chain wear.

IME, there's no reason to believe that replacing chains early saves any wear on a cassette. how could it? the chain is still rubbing on the teeth of the cogs. think about it for a minute or two.

IMO, to save money on drivetrain components, clean the chain regularly and buy steel cogged cassettes. not advice i always follow WRT cogs. but all in all it's not much of an economical burden IME.

Right, but the mismatch in pitch between the elongated chain and standard spaced cogs causes more wear on them than when the fit is perfect. Just to anthropomorphize things a bit think of the chain trying to get comfy as it gets bigger and bigger and has to carve out more space between the cog teeth to sit properly in the groove.

i tend to think that it is carving out space with every turn of the crank... more so when dirty.

in my mind the chain is alternately applying varying amounts of force, depending on how hard one is pushing on the pedals, on the back edge of several teeth on the cog at all times, wearing that back edge. unfortunately, as it wears it also ramps up,

edit:



(two cogs, worn and unworn, superimposed, eventually the chain slips over the top given enough force and chain slack, and the feeble spring in a derailleur's chain tensioner can accommodate that with ease.)

end edit:

and the chain begins to ride higher and higher on the cog. eventually it begins to slip over top of the cogs. this is facilitated somewhat on bikes equipped with derailleurs and their spring loaded chain tensioners (the phenonenon is rare on bikes that lack them, in as much as it is difficult or next to impossible for the chain to skip over the teeth due to a lack of slack available in a properly tensioned chain), this is observable on a well worn cog/chain. in my mind changing to a new chain cannot stop the process.

like i said, it's not much, cost wise, IME, unless one is buying titanium cassettes, and if i did buy titanium cassettes i would probably think about the whole issue a while heck of a lot more than i do now. and want some serious independent studies that provide convincing evidence one way or the other WRT to longevity. i know of none, but i would find the reading of interest if i were to find any.

it's really just another of those "lube" issues.

My Red cassetes are about the same price as partial Ti cassettes so it is a big deal to me.

i feel your pain.

ya, i'm not sure what i would do if bike weight were a concern and i needed a cassette (and i'm not saying it isn't) ...

to come to a satisfactory i conclusion i suppose i would probably use two bikes and ride them on alternate outings. change the chain and/or cogs by whatever methods i was comparing. maybe one based on chain length measurement and replacing the chain accordingly. and the other on skipping, and changing the chain and cogs when skipping occurred. keep track of costs and wait five or ten years to even out the highs and lows, then compare costs.

like THAT's gonna happen...

really, until then it's a faith based question as far as i am concerned as to what's more economical.

Yeah but his 5800 cassettes are like $30 so chain wear doesn't have to keep him worrying at night.

I bet they used a cheap chain checker and it's only like half worn.

Using milage to switch or comparing your milage against others doesn't work. There are so many variables, it can't work that way. For example rider weight, amount of hills, seated or stranded climbing, spinner or masher, cadence, frequency of shifting, type of lube, frequency of lubing and cleaning, etc.

Just measure wear and replace when necessary.

actually, the whole question may become moot once Shimano comes out with their new electronic derailleur featuring a separate chain tensioner and derailling mechanisms. when that happens we can just about run our cogs and chains until the teeth on the cogs and the rollers on the chains wear completely through.

the tensioner, i expect, will mount on the chainstay, somewhere between the rear dropout and the BB shell. and it's single jockey wheel (with the chain running either above or below it) and sliding adjustment mechanism/motor will be triggered by shift changes. the necessary tooth count of origin and destination cogs are in a chip in the cassette.

and here's the important part. it will keep the chain rigidly fixed and with the proper tension at all times, with just enough slack to accommodate cog and chainring roundness and spindle and freehub concentricity errors. the advantage is that with a ridged and accurate tension the chain cannot skip unless the teeth on the chainring or cogs, or links in the chain are broken.

don't expect this anytime soon. because once the board finds out that they are paying employees in the engineering department to do something (i.e. prevent premature wear of chains and cassettes) that is at cross purposes with those they are paying in the sales department to do (i.e. sell MORE chains and cassettes), they will put and end to it, pronto.