As above – is there an easy rule to follow?
Thanks

Same as for any other system….
No calculation as such necessary at all.
Fit groupset, put chain round two smallest sprockets and cut so the mech cage is parallel to the floor (9 o’clock position) and the chain isn’t rubbing back on itself in the mech
1x and 2x systems usually work best with a link or two less then that to keep more tension in the chain. This is where Powerlinks come in useful: Cut chain as above and then see what it’s like on big/big. If the mech isn’t sitting at about the 4-5 o’clock position then loose another link.
Easy. I do probably 20 chains a week like this. Never fails. (Unless someone has incorrectly specced the ratios and mech capacities…)

Thought the normal rule was big big (bypassing rear mech) +2 links?

Stu – that’s the one I’ve always worked to. Seems about right on my 1×11

As above. Big-Big not threaded then add two links. You can get away with adding more on a 1x.

Big-Big +2. If its a full sus worth running it through full travel to check any chain growth, as may need to add extra links if it changes significantly through the travel.

If its a full sus worth running it through full travel

yeh, that bit
let out all the air (or remove spring) from shock & compress fully, then big:big + a bit

Same as for any other system….
No calculation as such necessary at all.
Fit groupset, put chain round two smallest sprockets and cut so the mech cage is parallel to the floor (9 o’clock position) and the chain isn’t rubbing back on itself in the mech

I’ve never heard anyone doing it like this before

Genuine question – why not thread through the mech on the basis that’s how the chain will be running in reality?

Only because threading it theough is harder to do and not needed. You don’t need to hold the chain in tension against the mech, just wrap it round and find the right link to remove. Pop the link out while it is loose then thread it all up and link it. Piece of cake

In big/big you still need a noticeable bend at the jockey wheels. Do that by hand and add a power link if you want.

If you’re taking an old chain off, count the links and put on a new one the same length.

I am very much in agreement with PP on this one.

Too tight is how you break rear mechs into spokes.

My only issue with PPs method is it seems an 11-28 cassette would have the same length chain as an 11-32 or bigger.

Yes but if you were on a 32 the length in the mech cage would allow for this.

If you set chain length small small as PP says, it will work fine. Problems arise when folk use the wrong rear mech for their gearing.

Unless you’ve put the wrong mech on. The big-big method would result in a sloppy chain, the small-small method would break the mech.

Sizing using the largest cog without threading the chain through the derailleur + 2 links is, in my opinion, the correct one.
SRAM recommends adding 4 links, but I suspect this is for allowing a larger chainring if you find you need one later – I went from 30 to 32 without any issues using large + 4.

I’ve never heard anyone doing it like this before

I’ve always done it, that’s the way I was taught for my Cytech and that’s how at least 3-4 other mechanics (that I’ve noticed anyway…) do it.
Reason? You leave as much chain as possible. It’s always at least a link longer than the mech can take in big/big (As long as you’ve worked your capacities out properly…) and leaves you the option of removing a link should your chain snap 🙂

My only issue with PPs method is it seems an 11-28 cassette would have the same length chain as an 11-32 or bigger.

Which is fine. As long as you’ve worked your capacities out properly….!

the small-small method would break the mech.

Absolute twaddle. I do this every…single…day….of….the….week and it’s never, not once, caused a problem.
How on earth do you come to that conclusion, anyway?

Genuine question – why not thread through the mech on the basis that’s how the chain will be running in reality?

No reason at all. That’s what I do. See above 🙂

I am very much in agreement with PP on this one.

Too tight is how you break rear mechs into spokes.

Cheers 🙂

Absolute twaddle. I do this every…single…day….of….the….week and it’s never, not once, caused a problem.

you fit chains on bikes with the wrong sized mech (which is the case you selectively quoted from) every single day?! Might be worth checking 8)

Bear in mind that fully compressed on a full suss won’t always be the position that requires the most amount of chain, it could be at some other point within the bikes travel, it may be more fiddly but check through the bikes travel for the point that uses the most chain
Big-big + 2 pins (1 inner set of links + 1 outer pair of links) worth of extra chain (assuming full suss requires no more chain) cant go wrong
why would you ever be running in small-small? unless you’re taking the wheel out?

I also use the PP method (as it will be henceforth referred) on a daily basis with no problems. It works perfectly for 1X applicationsas these use clutch mechs so there’s no need to keep the chain short to prevent chain slap (as some incorrectly do).

Yup, fully compressed is no good, you need to cycle it through the full travel.

Really no idea why anyone uses a method other than “Put the chain on the bike. See how much chain you need. Use that much chain” tbh.

you fit chains on bikes with the wrong sized mech (which is the case you selectively quoted from) every single day?! Might be worth checking

Oops, soory, didn’t read your post properly. Apologies. 😳
Yes, you’re right.
But nobody fits the wrong mech do they….?? 😉