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I have a modest commuter bike with Shimano 3x7-speed Tourney gruppo on and I ride quite a few miles on it. Compared to my 105 11-speed road bike, I noticed that chains don't quite last as long ... on 105, I get about 5000 km life out of it and it's not even worn to death, the 7-speed chain (CN-HG40) is pretty much done after less than a third of it usually and that's not much if you commute 100-200k per month plus some other rides...

Of course, just as I'm used to from my road bike, I try to keep it clean and lubricated within reason but that didn't change much in lifespan on the 2nd chain I'm through within the last year. Cassette is OK, looks far from pointy and shifts absolutely fine with new chain on, no skipping etc...

I'd like to get more life out of the chain, there is a CN-HG71 chain which should fit but seems to be e-bike spec. Is it worth a try running that one on a normal bike and get more life out of it or can I expect similar wear from it while its indeed a bit pricier (not that it matters at retail prices from 10-20€).

Are there some other fitting non-Shimano options, even if it doesn't shift as crisp, my standards here are not as high as for my other bikes, to be honest ... 😜

Thanks for your input!

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    Aside, consider that your commuter rides in arguably worse weather than your nicer bike, so accelerated wear is to be expected.
    – Criggie
    May 24, 2023 at 19:26
  • @Criggie Sure thing but it's not as is if I would grind out 1000 km on a gritty chain, I have my standards here as well, so I'd say that the 7/8/9-speed "narrow" chains just aren't as good as those on modern road groupsets, by a mile ...
    – DoNuT
    May 24, 2023 at 19:31
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    @DoNuT if you concern is wear, I recommend you to consider wax instead of lube. According to this website (zerofrictioncycling.com.au) it helps quite a bit (and having a clean chain is nice on a commuter too).
    – Renaud
    May 24, 2023 at 20:51
  • @Renaud Yeah but isn't that a bit over-the-top for a commuter at the end of the day? I mean reading the cyclingtips.com source quote in the answer below, it just seems that Shimano has improved the pin construction from 10-speed upwards and these older chain series are just expected to be wearing out fast. I'll try to find out of there was some technology transfer to the HG-CN71 model or if KMC etc. have durable alternatives, it's not about marginal gains and maintenance geekery on an everyday bike, I just don't want to swap chains 3 times a year. 😉
    – DoNuT
    May 25, 2023 at 5:31
  • @DoNuT good point, and that's why it's a comment and not an answer - that being said, there are some people here that are commuting on waxed chains. Seems to me like a "different time distribution" (slightly bigger chain maintenance operations, but more spaced, and some time gains on cleaning - I ride in dusty conditions, so wet lube is not ideal). I only started recently to wax the chain (drip wax though, not hot wax, but that's in the program), but so far I like.
    – Renaud
    May 25, 2023 at 5:59

3 Answers 3

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My experience with chains is that some simple chain care and selecting high-quality chains helps a lot.

I have gotten 4000 km from the original chain of my 10-speed e-bike (with Tiagra components but not sure if the chain is Tiagra or Ultegra or something else -- I'll replace it with Ultegra once it's worn). It isn't still 0.5% worn and I expect I do the next chainwear check the next time it starts squeaking which should be at about 4500 km. And note this is an e-bike and that I used to weigh more than 100 kg for most of that 4000 km I have ridden. Given those specs (over 100 kg weight, e-bike), chainwear should be very fast but I seem to be getting more kilometers out of it than would be expected given the strict 0.5% wear limit I adhere to.

There is a chainwear article with broken images here but fortunately Wayback Machine helps: https://web.archive.org/*/https://www.cyclingtips.com/2019/12/the-best-bicycle-chain-durability-and-efficiency-tested/ (select old enough version to see the images)

The 8-speed chain, HG40, wears indeed very fast. 9-speed HG93, 10-speed CN-6701 and 11-speed CN-HG701 have far longer lifetimes.

What they didn't test is equal spec 8-speed with equal spec 9-speed (if you can find matching pairs anymore).

However, this shows that with the move to thinner chains, chainwear doesn't automatically increase. Better manufacturing can offset the drawbacks of thinner chains. I suspect if you choose CN-HG71, you can get some of that better manufacturing for 7/8-speed systems too even though it may not match HG93 and CN-6701.


About the chain care. What you want to do is to never add oil to an oily and dirty chain. All the oil does is to help attract more dirt, and help that move to chain innards near the pins where it can do the most damage.

What you instead want to do is to wait until you can hear the slightest amount of squeak. It means the chain is starting to run dry. Then the rollers are shiny clean. The chain innards near the pins are quite clean too, since there's little oil to attract dirt so there's little dirt too. Clean the exterior of the chain with stiff brushes and specially reinforced paper towels for about 10 minutes. Once it's acceptably clean, oil it with thixotropic motorcycle chain lubricant. This lubricant is good for about 800 km. Wipe the excess lubricant away with a specially reinforced paper towel. Then you're good for the next 800 km.

So the idea is that since it's hard and messy and requires lots of hard-to-dispose solvents to clean the chain innards, you use the natural cleaning action. Once the chain starts to run dry, the dirt isn't held inside the chain anymore and can find its way out. The side plates will be dirty though in the parts that don't rub against each others, but that you clean with brushes and paper towels.

The important thing here is to react as soon as you hear the slightest amount of squeak (best to react in 50 - 100 km since even 150 km of riding with a squeaking chain can do lots of damage). If you let it squeak for too long, the lack of oil wears the chain very quickly. So there's a balance. Adding oil every 100-200 km means it's continuously full of oil and full of dirt (fast wear), waiting too long to add oil means it wears from lack of oil (fast wear too). But an optimal oiling interval based on hearing a very slight amount of squeak means the wear is very low and chains last long.

Now, theoretically you could remove the chain away from the bike for very thorough cleaning every 100 km before adding oil. It requires lots of time so not worth it since you could spend that time riding instead of working on the bike. I suspect it would however increase chain lifetime somewhat over the brush/paper towel cleaning every ~800 km. Also theoretically you could use on-the-bike cleaning machines every 100 km before adding oil. However, they make a huge mess, require lots of solvent and oiling a chain that hasn't fully dried from solvent probably doesn't make sense and drying the solvent is best done on a hotplate and you can't obviously put a chain on the bike over a hotplate.

So-called dry lubes require so frequent application that I'm almost certain they make no sense, since even though they don't attract dirt as heavily, they can still carry dirt inside the chain, and it doesn't make sense to clean that dirt away so frequently and oiling a dirty chain with any kind of lubricant is a big NO! But it certainly makes sense to quickly clean dirt away every 800 km which is the interval needed for thixotropic motorcycle chain lubricant. Also dry lubricants probably are not as good as lubricants -- ever seen an internal combustion engine lubricated by a dry lubricant?

I'm sure this answer will be downvoted by a huge horde of wannabe racing cyclists who fear how many watts you lose by not oiling the chain before every ride. But once you stop fearing about watts, you will see that it's very simple to extend chain lifetime a lot, it doesn't require really much time, it can even save time since you don't have to change the chain so frequently.

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    Thanks for the comprehensive answer, but to be honest, as I'm an avid road cyclist, I'm aware of good chain care. I use dry lube on my road bike because I hardly ever ride in wet conditions (would rather go for a run, then) and am happy that I don't have a dirty drivetrain just from dust picked up by an oily chain. On the commuter, I do the opposite because I ride in every condition and the from-factory lube all over the chain protects the chain from rust etc (especially in winter). On my 105 group, if often clean the chain before even riding with the greasy new chain once. 😜
    – DoNuT
    May 24, 2023 at 18:15
  • I tried cleaning the chain so that it is never dirty and "only lubricate as much as need", i.e. links only and wiping off excess oil but in winter, the outer plates of the links started to rust (even though I wiped the chain dry when riding on wet roads). Now I'm back to an off-the-shelve lube/protection spray because it is easy to apply on the whole chain and blocks off rust - the flipside is the chain picking up more dirt but that can be cleaned, unlike rust ... problem is, CN-HG40 is just s**t compared to Shimanos newer and higher-spec chains.
    – DoNuT
    May 24, 2023 at 18:18
  • I just checked the cyclingtips article and the measure wear is higher than my real-world results but in the same ballpark if you add about 50%, so a CN-HG601 does about 5k to 0.5 wear and CN-HG40 is probably at 1k by that point and then falls apart even faster - with 300km more on the clock, it was more than read to go. At least the Tourney cassette seems to be sturdy and doesn't mind those ever-wearing chains.
    – DoNuT
    May 24, 2023 at 19:49
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(I will keep editing this self-answer with my experiences since I posted the question. Due to the platform's policy, this isn't meant as product recommendation, I just want to share my process in optimizing chain life on a common cheap bike and what I learned...)

When you have a 6/7/8-speed bike, the recommended replacement part will be the "standard" HG-40 chain. This technology has been there since the 80s, since then we got up to 12-speed chains without cross-compatibility.

My results with the HG-40 are consistently bad and the wear test in the accepted answer shows that every improved design has better longevity than the "original" 7-speed chain design.

I've run 3 HG-40 chains in all-year riding and I pretty consistently got 800-1000 kilometers out of each. Since I usually clean the chain only once a month (worth 200 km of riding), I discovered between 0.75 and 1.0 wear on all of these. With stricter checking, I would have replaced chains earlier.

It is not a strict comparison because I am running the same cassette and chainrings but it is a budget bike but wear doesn't look too bad and I've never got any shifting/skipping issues.

Here just some images from an original (HG-40) chain after less than 1000 km, my BBB chain gauge slots in, indicating 1% wear.

enter image description here

I also did a bend test vs. a new chain to illustrate the wear.

enter image description here

Finally, my (updated) results with various chains used on the bike

Shimano HG-40

  • Original-spec Shimano chain for 6/7/8-speed drivetrains
  • RRP: 17,95€
  • Chains run: 3
  • Life: 800-1000 km, all chains were close to 1% wear
  • Prone to rust

KMC X8

  • RRP: 17,80€
  • Chains run: 1
  • Life: Swapped out after 600 km, close to 0.75 wear
  • Riding in all winter, definitely better rust resistancy than HG-40, still looks like new

Shimano HG-71

  • A refreshed 6/7/8-speed design from Shimano to meet the needs for e-bikes, potentially more durable due to that
  • RRP: 29,95€
  • Currently fitted (Feb '23)

(Prices are recommended prices, in real life, these are much closer together)

Conclusions

Summing up some aspects from discussions in comments here:

  • 6/7/8-speed is old-tech and not used on top-end bikes for decades, so there was no real need to refresh the technology or improve tooling for manufacturers. These chains are typically seen on entry-level bikes, if somebody is riding only once a week in good weather, replacing a chain every 1-2 years won't be a huge problem
  • Cost is low: You could argue that replacement parts are cheap, a HG-40 chain costs about 10€ on various online retailers in the EU. So, even if you need 4 chains a year, that is still cheaper than a single Dura-Ace chain
  • There is no interest for manufacturers to improve the design since the high-end market has long moved away from 6/7/8-speed. Shimano might still be running the same or similar manufacturing tools as in the 80/90s, additional engineering cost would not allow to hold such a low price. Alternate offerings (like the praised Wippermann chains) often cost 3-4x more, this is very likely a cost/scale issue: Other manufacturers don't produce at such large scales and if they invest in durability by using better designs/materials, prices go up - a 8-speed Wippermann chain costs more than 11-speed Ultegra CN-HG701!

However, on a budget (very likely on a 7-speed bikes), the best chain isn't necessarily the most durable or the cheapest one but rather a combination of the two. A 40€ chain that only lasts twice the distance will give you ease of mind because you swap chains less often but running costs are actually higher. I haven found the sweet spot, my hopes are that the HG-71 is the go-to in this scenario (yet to be confirmed)

Here is a link to a Zerofrictioncycling article:

https://zerofrictioncycling.com.au/wp-content/uploads/2018/04/chainlongevitypg1.pdf

This test backs up the bad performance of HG-40, ranking dead last in the wear test and also in the upper third in terms of costs, being outranked by most of its 10/11-speed Shimano friends. The 11-speed 105 chain is the most cost-effective chain in the test, so I was comparing extremes in my initial question, wondering why I got some much more milage out of my 105 bike.

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    I am about to do the reverse, going from KMC X8 to Shimano HG-40. Perhaps this comment will make me remember to post the results :)
    – WornChain
    Oct 4, 2023 at 18:53
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    @DoNuT did you try Wipperman Connex chains? From what I heard/read, their durability is very good — the TCO is between similar and lower than Shimano's according to what I could find on the web.
    – Renaud
    Feb 9 at 15:28
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    @Renaud I didn't because that sounded a bit too nichè for me, but I found a comparison in ZFC here. I'll consider it but my go-to shop has currently listed it at 4x the HG40 price and based on the graphics (2x the durability to HG40), I'm not sure if it'll live up to the expectations. If the HG71 sucks too, I'll give it a shot, though....
    – DoNuT
    Feb 9 at 15:40
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    @Renaud 90 percent of the internet's cycling community is US/UK-based (plus some Aussie folks on YT), the only decent German resources are some of the established magazines but they don't go into geeky details like chain life tests. I think 8-speed is just bad because there was no need to improve the design after road cycling has long moved on to 9/10/11/12-speed and you find these chains on cheap entry-level bikes like my commuter. Perhaps, there's also something inherently limiting with the pin/roller design that doesn't allow for good durability.
    – DoNuT
    Feb 9 at 16:02
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    @WornChain Very likely a cost/scale issue. I just checked, a 11-speed Ultegra chain I ordered for one of my road bikes is cheaper than the Wippermann 8s. I'm guessing, Shimano is making a lot more of these. My long-term solution will be commuting with my soon-arriving gravel bike and on GRX 12-speed^^
    – DoNuT
    Feb 9 at 19:30
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Try the KMC-X8.

After swapping chains a few days ago, my very non scientific and sloppy test shows almost no wear on my KMCX8 after 2000 km. (It is probably more worn than the picture indicates, and the method used is not very accurate). I never(in summer) clean my chain, but wipe after almost every ride and reapply lube 4-5 times a week since none of my lubes seem to hold out very well.

The image is a composite overlay of 2 pictures in which my 4800 km KMCX8 chain was used as a reference. The most worn chain ran a total of 4800km in both summer and winter(snow/salt/wet) with a mixture of lubes. The 2000km KMCX8 was only used in the summer and recieved a thin oily lube exclusively. I guess my cassettes (HG200-8) is my 8-speed weak point and winter/salt is a chain killer.

I've swapped to a Shimano CN-HG40 which feels smooth, but has a bit poorer shifting. This might be the new chain meshing less well with a worn cassette, so not conslusive.

Edit: As I pointed out in the comments, zerofriction put Shimano HG40 at the very bottom of the longevity test. HG71 might be better.

enter image description here

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  • Thanks! Already on X8, I know this question is on the edge of product recommendation but if I just come close to 2k, that's a lot more than I got out of HG40 chains and perfectly fine. Shifting performance doesn't matter, I mainly run 3 cogs on my commute. Not sure where I recently read it but it lacks hardened pins in comparison to up-spec chains and that's one of the reasons why HG40 wears out so fast .
    – DoNuT
    Oct 9, 2023 at 20:12
  • I'm swapping lubes, too. In the summer, I'm often running one of the oils I use for my road bike, in wet and cold conditions, I go a more specific product. However, I see no big difference compared to cheap off the home depot shelf...
    – DoNuT
    Oct 9, 2023 at 20:15
  • I am unfortunately not replacing the cassette so I will not be able to give a fair comparison on the chains after the next 2k. Winter is coming and I'm too cheap to put on a brand new cassette right before slush month begins. Going to avoid my own 3 favorite cogs instead and see how far I can go. I retracted my lube statement, so I deleted a previous comment regarding that.
    – WornChain
    Oct 9, 2023 at 20:33

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