BBB Cycling, ChainChecker Multi Tool for Chain with Bike Hook for Road and Mountain Bikes, Hand Tool, Measurement Repair Kit, BTL-125, Silver https://amzn.eu/d/gOMZdUp


KMC Easy Chain Checker Tool, Silver, Universal https://amzn.eu/d/e5HF8Gm

The KMC one seems to have accurate measurements, however it shows that if it's <0.8 then you're supposed to replace it but aren't you're supposed to replace the chain when it hits 0.75?

  • 1
    Neither. As mentioned in the answer. A ruler will always work. Jul 2, 2022 at 17:45

1 Answer 1


Usually, on this site questions that ask for specific product recommendations are discouraged. However, here it's important to note that most chain wear tools measure the incorrect thing. They do a measurement that's partially based on chain pitch, partially on roller clearance and partially on roller diameter. This measurement tells almost nothing.

You need a chain wear tool that does both measurements on the same side. As far as I know, there are only three families of such tools:

  • Shimano TL-CN40, TL-CN41, TL-CN42
  • Park Tool CC-4 (don't buy any other tool from the CC series, only CC-4 is accurate)
  • Pedro's Chain Checker Plus II

Of these, the Shimano ones have one threshold (probably 0.5%, not specified) whereas Park Tool and Pedro's have 0.5% and 0.75% specified thresholds. That shouldn't matter as you should be replacing your chain already at 0.5% so the 0.75% threshold most likely only tells if you already have destroyed your sprockets, which you will find out anyway after the chain change.

Here's more information about the problem with most chain wear tools.

So, to answer your question: neither. Both are crap.

  • They both measure 0.5% wear.
    – Sam
    Jul 2, 2022 at 8:50
  • 3
    @Sam this answer is trying to explain that whilst both chain checkers you linked may show 0.5% they are flawed in their measurement system.
    – Andy P
    Jul 2, 2022 at 8:53
  • @Juhist i believe the pedros branded chain checker also does a 'same side' measurement
    – Andy P
    Jul 2, 2022 at 8:55
  • I bought the Parktool CC-4, did I make the right decision? It is expensive.
    – Sam
    Jul 2, 2022 at 9:18
  • 1
    Buying Park Tool CC-4 is not a mistake, but using its 0.75% limit may be. However, it has a 0.5% limit too which causes less sprocket wear than 0.75%.
    – juhist
    Jul 2, 2022 at 9:26

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