How to calculate ch...
 

[Closed] How to calculate chain length?

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Hi Guys, newbie so sorry if this is a silly question - I have an SRAM 1X11 setup with 32T & 11-42T currently. I am maxing out on 2 hills on my ride so wanting to go to 11-46T for this. Before I purchase, is there any way of calculating whether I need a new chain or not? I've done some Googling but seems to be mixed results. It's a full sus bike (Bossnut Evo v2).

Thanks


 
Posted : 26/06/2020 12:31 pm
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How old is the current chain/cassette? If there's much wear you might need to stick a new chain on anyway.

I'd suggest you just buy a new chain anyway as you'll need it sooner or later. Try fitting the old chain on the new cassette, stick it in the biggest sprocket and carefully move the suspension through its full range (release one end of the shock to make it easier) to see how tight the chain gets.


 
Posted : 26/06/2020 12:38 pm
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Buy a new chain. Setup correctly your existing one shouldn't have 4 spare links in it


 
Posted : 26/06/2020 12:53 pm
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Setup correctly your existing one shouldn’t have 4 spare links in it

Isn't it more like 2ish links(i.e 1 thick/ 1 thin)? As the chain only wraps around half ish of the block?
Entirely feasible there may be an extra 2 in there.


 
Posted : 26/06/2020 2:33 pm
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Entirely feasible there may be an extra 2 in there.

I think the important part of the advice was "setup correctly".


 
Posted : 26/06/2020 3:01 pm
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Sram 1x

Measure psi on shock.

Deflate your shock completely, put a strap round it to keep it compressed.

Wrap chain around biggest cog and Chainring avoiding derailleur

Add 2 links.

Reinflate shock.

You'll find with inflated shock chain will be about 4 links long. But every suspension bike is different, hence you need to deflate


 
Posted : 26/06/2020 3:06 pm
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Air out of shock and work out where your maximum chainstay length is. On my (Horst link/4bar) bike it's somewhere around 2/3 travel if I remember right.

Then wrap as above round chain ring and largest sprocket and add 2 links past the point where the chain meets.


 
Posted : 27/06/2020 1:09 am
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Isn’t it more like 2ish links(i.e 1 thick/ 1 thin)?

That is 4 links. A link is quite literally the link between plates, eg the pins. It's nothing to do with the thickness of the plates etc.


 
Posted : 27/06/2020 11:02 am
 pdw
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Link is a bit ambiguous. Can mean from one pin to the next i.e. 1/2" or the shortest repeating unit i.e. 1" (although people typically say "full link" for this). The point is that if you add 4T to your sprocket, you only need to add 2T to your chain (i.e. 1" / 1 full link / 2 individual links)


 
Posted : 27/06/2020 5:09 pm