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I replaced my old chain with new one. Online chain calculators recommendation is 106 links. Currently the chain has 108 links. Do you think I should remove two more links?

smallest cogs

I'm not totally sure that I've correct chain length. It has just a little slack when the chain is on the smallest cog and lowest chainring as seen in the top photo.

Update: I removed two links (one inner and one outer link). Now it is 106 links as per @Michael's and online calculator's recommendation but unfortunately it didn't work out. Now the rear derailleur stretched out too much and the chain doesn't even properly sits or catches the teeth of the bottom pulley. Please see new photos bottom of the page. I think @Criggie was right.

big big

106 links big big

106 links small small

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    Sorry - we need a photo of the chain in the biggest tooth-count cog and the biggest toothcount chainring. That will show the angle of the rear derailleur when its fully "empty" of takeup. The angle and coverage of photos is spot-on
    – Criggie
    Sep 8, 2023 at 7:01
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    @Criggie There is a photo now. Doesn't look fully extended, still a slight bend in the chain as far as I can tell?
    – DoNuT
    Sep 8, 2023 at 9:15

2 Answers 2

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You could make that chain shorter, but its not overly-long, so while it errs on the slightly too long, I wouldn't bother with chain length changes.

There are two very minor positives about having a little slack in the chain:

  1. Your chain wear is spread over two additional links, which is about 1.9% improved chain life if we presume that more links means slower chain wear because it adds an extra inch to the chain.

  2. If you have an issue on the trail/commute that damages some of your chain, it is possible to use a spare master link to make something that is still rideable while removing the most damaged sections.
    If the chain were tight, you can't remove any and still have full range of gears.
    I've personally done this on my recumbent, where the chain is around 275 links.

Downside to a slightly too long chain:

  1. Weight - you're carrying another two links around. Perhaps 5 grams?

  2. Sag - as noted, the spring in the derailleur is a little weaker at the end of its travel, so it can't pull the bottom stretch of chain as tight. This lets the chain slap around a little more when in some gear combos.
    I can't speak to how a clutch derailleur would handle this situation.


As pictured, your chain reaches around both big-tooth-count cog and chainring without being too tight, AND it does the small-small pair without letting the chain rub on itself passing under the derailleur.

I think your chain is a fine length as pictured.

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    You were right. Please see new photos.
    – Ender
    Sep 9, 2023 at 8:43
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From the photos it looks like you can and should make it shorter.

Most chain tools come with a chain hook which is really handy not only for shortening and closing the chain but also for seeing how short you can make it in the big-big gear combination. If you position the hook right you can even check that shifting from the second largest sprocket to the largest sprocket still works with the hook installed (i.e. chain on its new, shorter length). Pulling on the chain while the hook is shortening it to its future length can also help to gauge how much slack the derailleur still has.

Generally you should make the chain as short as possible while still allowing smooth shifting from second largest to largest sprocket while in the big chainring.

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  • Unfortunately I don't have a chain hook. Why do you think I should make the chain shorter?
    – Ender
    Sep 8, 2023 at 11:08
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    Why you should make it shorter: In your photos in the big-big combination it looks like your derailleur still allows a good amount of movement and in the small-small combination there is very little (too little) tension. I think you can even see that the chain is sagging slightly.
    – Michael
    Sep 8, 2023 at 12:12
  • You were wrong mate. Please check new photos.
    – Ender
    Sep 9, 2023 at 8:43
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    This answer isn't wrong. The new chain length is fine as well. Yes, the derailleur is extended quite a bit to the front in the big-big combination, but neither the derailleur nor any other part is in danger of being damaged, and one shouldn't use the big-big combination anyway (it's inefficient and bad for the chain). There are pros and cons to shortening the chain. Michael's and Criggie's answers are both reasonable. Sep 11, 2023 at 14:15

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