Chain Length vs Cha...
 

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[Closed] Chain Length vs Chainring Help

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Hi all.
I’ve currently the stock SRAM NX Eagle 12sp on my hardtail with a 30t chainring and 11-50 cassette.
My question is, if I swap the chainring to a 32t (or possibly 34t) do I need to extend the chain and if so by how many links?
Cheers


 
Posted : 06/07/2020 10:43 pm
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test it
pull the derailleur a little to simulate the extra couple of teeth, if it is still under tension nad not locked, your golden


 
Posted : 06/07/2020 10:54 pm
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Thanks - didn’t think of that!


 
Posted : 07/07/2020 7:04 am
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Hardtail or FS bike - don't forget that on a FS, depending on design the effective chainstay may change as the suspension moves through travel. So if it's at all tight you need to let the air out of the shock (or better, unbolt one end) and then cycle it through the travel.

Saving £25 on a chain by reusing it will be of no benefit if on the first bump you tear the mech off.

[edit, sorry, see you said hardtail but I'll leave this up anyway in case anyone else is reading it for a FS]


 
Posted : 07/07/2020 7:54 am
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Two teeth is an inch, four is two inches. Put it on the big cog and push the RD forward and pull a kink in the chain. What does the rear derailleur look like? For two inches (four links), I’d swap the chain. One inch, probably not.


 
Posted : 07/07/2020 7:58 am
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Saving £25 on a chain by reusing it will be of no benefit if on the first bump you tear the mech off.

It won't rip it off, it'll snap the chain and maybe bend the chainring.


 
Posted : 07/07/2020 8:58 am
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It won’t rip it off, it’ll snap the chain and maybe bend the chainring.

I've seen is snap the parallel linkage on the mech

Two teeth is an inch, four is two inches.

The chain only wraps half the ring so 30 to 32 is 15 to 16 teeth of wrap, half an inch


 
Posted : 07/07/2020 9:02 am
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Thanks all, On the 50t cog I have about 1 outer link of chain to play with before the derailleur locks out So I’m just going to play it safe and get a new chain. Cheers all


 
Posted : 07/07/2020 7:19 pm
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I’ve seen is snap the parallel linkage on the mech

Not exactly the same as "rip it off", is it?


 
Posted : 07/07/2020 7:25 pm
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You used the phrase rip it off!

Did the mech hanger on mine. ie, pulled the mech off. I know they're made to be sacrificial but if they don't go I'm pretty sure the mech would go quicker than a chain that's designed to have a large amount of stress through it!


 
Posted : 07/07/2020 9:00 pm

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