[Closed] Correct Chainlength For 1x9 Setup?

Simple answer is as short as possible.

Remove as many links as you can, get that chain nice and tight. If you remove too many, add one back in.

No magic formula or anything, just as short as you can get it.

Best and most trusted 1x9 chain length calculator I've used is -

Shift the bike into 1st.
Remove shock spring/air from shock.
Compress the suspension.
Fit the chain, add or remove links until the mech is almost at full stretch.

If its 1x9 on a hardtail then

Shift the bike into 1st.
Fit the chain, add or remove links until the mech is almost at full stretch.

job done.

been using this method for 10 years

you will find if you "guess" the chian length the chain maybe too short this will have a massive effect on suspension action. the chain may stop the bike getting full travel. leading to snapped chains or at worse ripped off mech hangers from frames. too slack and the chain will flap around all over the place

large to large, not thru the mech and 2 links. If its a full susser compress the suspension to the point chaingrowth is greatest

simple and just works

the old rubish add two links rule what a load of balls

Cheers i had a feeling it may be done by the big/big combination. Its on a hardtail so no suspension gubbins to worry about 😉

14 foot 6.

I use the following method...

Wrap the chain round your chain ring cog (without going through rear mech. Then around the largest cog on the cassette, note where they meet add +3 for shimano chains without quick link and +2 + quick link for KMC/SRAM chains.

always worked for me.

the old rubish add two links rule what a load of balls

just out of interest why is it balls? what 'should' I be doing?

just out of interest why is it balls? what 'should' I be doing?

doesn't take into account mech length.

Nothing wrong with the add 2 links rule & no reason it shouldn't work on a 1 x 9 set up just as well. Been building & fettling bikes for nearly 40 years & always worked for me.

add two links is how I have done all my bikes for many years, it ensures the chain is as short as possible

Should be using a short cage mech on a 1 x 9 set up anyway

Should be using a short cage mech on a 1 x 9 set up anyway

not all people do

why does the mech length make a difference?

why does the mech length make a difference?

think about it......

more or less chain passing through the mech depending on the mech length. adding two links maybe too much for a short cage mech - leading to incorrect chain length
and maybe too short for a long cage mech leading to incorrect chain length

@ Greeble, thanks for the explanation. But i thought adding in the 2 extra links accomodates the rear mech? I actually add 3 as this is what it said to do in a book I had. 3 for shimano and 2+ quick link for chains with quick link.

Cheers Dicky... I'll stick to what i know then.

don't agree greeble - the mech length makes no odds at all - + two links works fine for a long cage and if you go short cage you would not want the chain any shorter

+ 2 links we know works for a long cage mech on a 3 x 9 or whatever setup, with a 1 x 9 setup the overall tooth capacity is smaller so a mtb short cage mech can be used & because of the length of the mech a shorter chain might be able to be used - I would go with +2 links, try it & if too long take another link out (easier to remove 1 than add 1 afterall)

TJ, you're talking tripe again

Mech length of course makes a difference. Shorter cage mech is going to have less chain running through it...

Trying to use a formula to work out chain length isnt perfect. Just shorten it to as short as it can go, whilst still being able to get every gear. If you shorten it too much, add a link back in...

Mboy - sorry I don't see it - when in big / big the chain is almost straight along its bottom run - the short road mech and the long mtb mech I have are both the same and taking another link out would make the chain too short on the road mech despite it being much shorter mech - its still big / big + two links is the shortest chain possible

Edit - the plus 2 links is not a good start for 1 x 9, the formula for 3 x 9 is big to big plus 2 links is only okay because you should never actually ride big to big. Setting up a 1 x 9 in the same manner will prob result in too short a chain when riding on the largest sprocket.

Edit - the plus 2 links is not a good start for 1 x 9, the formula for 3 x 9 is big to big plus 2 links is only okay because you should never actually ride big to big. Setting up a 1 x 9 in the same manner will prob result in too short a chain when riding on the largest sprocket.

Hense why this...

Best and most trusted 1x9 chain length calculator I've used is -

Shift the bike into 1st.
Remove shock spring/air from shock.
Compress the suspension.
Fit the chain, add or remove links until the mech is almost at full stretch.

If its 1x9 on a hardtail then

Shift the bike into 1st.
Fit the chain, add or remove links until the mech is almost at full stretch.

works best

Plus 2 links does not produce too short a chain on a 1x9 - it makes one exactly the right length - 2 bikes I have set up like that

Plus 2 links does not produce too short a chain on a 1x9 - it makes one exactly the right length - 2 bikes I have set up like that

keep kidding yourself

greeble - I have had two bikes running 1x9 with chain setup to big / big plus two links using long cage mechs and it is perfect

TJ - sounds like your mech is near horizontal when in biggest sprocket which aint right in my book

Yup - thats right - as short a chain as possible is best in my book. Less chain slap / less chance of the chain coming of.

http://sheldonbrown.com/derailer-adjustment.html#chain

i thought you were a big fan of a granny ring TJ, or is that on other bikes?

The 1x9s are / were commuters. (one got nicked)

I agree with the general consensus but be careful when setting up a full suspension bike as the longest effective chain length on many bikes, including mine as I found out to my cost, is not at either end of the travel but about 1/3rd of the way through. My bike has a VPP link system so the path of the rear wheel is backwards and then up in a sort of C shape. As a result there needs to be enough slack in the chain to allow for the suspension to follow its path.

Plus 2 links does not produce too short a chain on a 1x9 - it makes one exactly the right length - 2 bikes I have set up like that

tried that on my 29er with a short cage mech and it was way to short..

What have i started?? 😆 😆
Its an old school M952 long cage mech

Its an old school M952 long cage mech

Oooh, if you want a tatty, but functional, short cage version of the same, I still have one kicking about somewhere I think from when I ditched 9spd to go to 10spd. Short cage definitely helps reduce chain slap and aids keeping the chain on in a single ring setup.

Just checked mine & with the rear mech as taught as I'd be prepared to go (ie still making a S shape in the chain) mine is just about big to big plus 3.25 links with a short MTB mech - on a hardtail frame.

this is pretty much how I did mine.

holy mother of erroneous thread resurrection batmen..

this method of largest chainring and largest cassette cog +2 is for a 3x9 set-up yeah..? Where you'll never be in largest/largest..?

so..
how do we find the correct chain length for a 1x9 set-up..?

or a 2x9 set-up for that matter..?

I took Mrs Yunki's bike to an LBS that I haven't used before recently, and they gave me her bike back with a ridiculously short chain.. brought about by using the 3x9 method on a 2x9 set-up..

I'm about to fit a chain on a 1x9 set-up and would like some sound advice please.. 🙂

On my HT with a 32t front & a 36t rear with a normal (probably long) XT mech I'm on "big/big +3" and it works just fine for me

Yunki - listen to greeble.

TJ was talking pish yet again

On my 2x9 I use big,big +3 then add a powerlink.

My 1x9 is probably about the same.

"brought about by using the 3x9 method on a 2x9 set-up.."
So?

TJ is right no?

If you were setting up 3x9, ignoring full suss extensions for the minute, youd go big big (not through r.mech) and overlap 1pair/2links(inner+outer) and chop chain, to make sure it shifts properly (sometimes youll get away with 1.5links or so overlap (3/4pair)

If you were setting up (bash+)2x9 or 1x9, you still go biggest-biggest (not through r.mech) + 1pair/2links(inner+outer) overlap and then chop chain

Cage length makes no difference to chain length
No you shouldnt ride big-big for cross chain inefficienencies, but setup right you can ride big-big
With 1x9 and/or short cage mech as it wont slap around the same as a long cage on a 1x9 setup you want the chain as short as possible but still want all your 1x9 gears
In biggest-biggest in both 3x9 and 1x9 the mech will be almost flat/parallel with the chainstay. The 1pair of links/2links(inner+outer) makes up for this almost straight bit

This is my about 0.5 link length(~0.2 pair of links length) overlapped SS
If it had a proper at least 1pair of links length/ 2 links length(inner+outer) overlap it would run properly with no tightness
Being Singlespeed its in biggest-biggest, so mech is almost flat. The cage length would make no difference to what length the chain should be:
[img] [/img]
(mech is too worn for geared use, and actually its a 2x1 .. but 22T ring is only for 'emergencies')

"+3 then add a powerlink"
?
I see, then you only need overlap '+1' and add a powerlink, as these 2 makes up your 1pair links length/2links length(inner+outer)

Hmm, I think what Ive written will read quite confusingly

I get the impression there is some confusion through this thread (other than whether cage length makes a difference to minium chain length) as describing length of chain regarding length
It seems 2 links means 4 chain pins worth of lenght to some, 1pair of links means 1 chainpins worth of length to others and 1 pair of links is 2 chainpins worth of length to some more ..

No TJ and now You too are wrong.

Why?
I dont get why cage length makes a difference to how short you can get your chain
Somebody tell me what Im missing here, I could be missing something, but I dont see?

Just to clarify - On my 2x9 I run big to big then add 3 links and a power link. So I'm adding 4 individual links (2 inners and 2 outers). No idea if the standard plus2 Is 2 individual ones or 2 pairs or even how the power link comes into the equation. Mine works so that's all I care about. 🙂

Greeble already told you, it's balls!

You've had 5 months to work out why, I'll give you another 5 and if you're still struggling with it I "might" tell you why then.

I don't know what reasoning there could be for big / big plus two links not being the right chain length - it works for any hardtail setup Teh plus two links gives enough slack for any mech in the gear combo tht has least chain slack

Sheldon Brown says it is right

The best technique for setting chain length is to thread the chain onto the large/large combination, without running it through the rear derailer. Mesh the two ends on to the large chainwheel so that one complete link (one inch, -- one inner and one outer half-link) overlaps. In almost all cases, this will give the optimum length.

You want a chain as short as possible. Stops it dropping off / slapping around. Usual load of pish on here from folk. 🙂

It works for 1x9
[url= http://farm8.staticflickr.com/7058/6984851070_4c88d99df1_b.jp g" target="_blank">http://farm8.staticflickr.com/7058/6984851070_4c88d99df1_b.jp g"/> [/img][/url]
[url= http://www.flickr.com/photos/25846484@N04/6984851070/ ]IMG_2687[/url] by [url= http://www.flickr.com/people/25846484@N04/ ]TandemJeremy[/url], on Flickr
It works for 2x9
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[url= http://www.flickr.com/photos/25846484@N04/7130935661/ ]IMG_2688[/url] by [url= http://www.flickr.com/people/25846484@N04/ ]TandemJeremy[/url], on Flickr

Note both mechs sitting at the right angle - not too tight - the 1x9 bike has the sweetest shift of any bike I have ridden.

Great reasoning here..."you're wrong because you're talking balls"

Thanks for that giggle!

"brought about by using the 3x9 method on a 2x9 set-up.."
So?

TJ is right no?

surely though... mech size is irrelevant to my query..

If you have 42 tooth largest chainring and 32 largest sprocket (a combination which you will never use)
that will give a certain length for the chain which works very nicely across a 27 gear spread..
I don't see the logic in applying that same technique when measuring a chainlength of 32/32 where you will often be using big/big..
the maths and physics and logic do not add up.. you're using the same spread of gears in that chainring, but with a drastically shorter chain..

teej, sorry mate, I didn't open this thread as an attack on you, just a genuine enquiry..

doesn't having your rear mech over extended like that put extra strain on cables/pods/spring and allsorts..? it looks all kinds of uncomfortable

i also have used the same method as TJ 2 chain links and its never failed on various bikes and mechs.

How many single ring set- ups have you fitted TJ?
- guessing not even in double figures, right?
Your "made up" rule is NOT even always possible never mind giving optimum chain length.

Yunki - very little to do with mech cage length.

plus one for TJ's method.

i use it on all 9 bikes that i own (various mtb/cx/road/single/double/triple permutations), and have never had a problem in several years.

oh look..

there's an in depth article on how long a chain should be

http://www.pinkbike.com/news/Tech-Tuesday-Chain-Length-Basics-2012.html

again so many people don't have a clue and the who +2 links thing is utter rubbish

you will complain the suspension isn't working correctly so need a PUSH tune or a CCDB because the chain length is too short not taking into account the chain growth on a full sus bike and all you've done is got the chain length wrong

Greeble - I said you need to do this with the suspension in the position that the effective chainstay length is greatest with fullsussrers.

GW - how could it be not possible? teh plus two links gives enough slack for any mech to go in.

YOu need to provide some reasoning why this is not right as its the standard method

"complain the suspension isn't working correctly so need a PUSH tune or a CCDB because the chain length is too short not taking into account the chain growth on a full sus"
the biggest-biggest + inner+outer chain length overlap rule does work on a full suss, you just have to measure where the effective chainstay length is at its longest (wherever that point maybe within the suspension movement)
Its what the shimano instructions that come with chains/casettes/mechs/shifters show on them

" rule is NOT even always possible never mind giving optimum chain length"
When is it not possible?
With a lower roller front chain device youd have to loop through that to 'measure' I guess?

teej, sorry mate, I didn't open this thread as an attack on you, just a genuine enquiry..

no worries

doesn't having your rear mech over extended like that put extra strain on cables/pods/spring and allsorts..? it looks all kinds of uncomfortable

TJ - are you going to answer my question? (seeing as I'm about to answer yours)

firstly it seems you can't count, in both your pics you seem to have added 4 links. (one chainlink comprising of just 2 plates)

many suspension frames have too much chain growth for just 2 extra links or even 4.
some set-ups (hardtail or full sus) will work smoothly with just 2 extra links added some will need 4 or more to opperate smoothly.
even on a hardtail chainstay length variance can add up to an inch (or 2 links) variance between what length chain will run big to big and what won't.
size of the chainring and large sprocket also play a part in what works smoothly
Which particular mech you are using will also play a part.
even mech cage length and number of jocket wheel teeth play a tiny part
as does mech hanger bolt location and chainstay design.

Believe me when I tell you from a huge amount of experience it's not as cut and dried as you seem to think.

Ps. What would your beloved Sheldon say about running a worn out guide pulley on an ancient but top of the range rear mech?
I'll tell you, he'd probably say "it is not ideal" but he'd probably still run it being a bit of a pikey..
same goes for your "standard"

One chainlink is an inner and an outer link

I said yo have to measure this n full sussers at greatest cheffective chainstay length

even on a hardtail chainstay length variance can add up to an inch (or 2 links) variance between what length chain will run big to big and what won't.

How - the chainstay length is fixed on a hardtail - this is taken into account with the amount of chain big - big

Thats not a worn out jockey wheel - I have much used much worse 🙂

Ihave set up a goodf few bikes over the years no idea how many but not dozens of 1/9s

oh. FFS.

you seriously think every hardtail has the same length chainstays?

No I do not - but it is irrelevant. Yes a longer chainstay needs a longer chain - but you get the greter length form the length you measure on the big to big. then you add two links to get enough slack to fit a mech.

So a chain measured on a bike with a short chainstay will be too short on a bike with a long chainstay but the beauty of the big / big plus two links is that it takes account of this

Ps. thanks for answering my question.
You really don't have anywhere near enough experience to be blindly chucking "standards" and "rules" about ass gospel.

If yo could explain a situation where this wouldn't work..................

Ok, You don't "get" it, fair enough, why would you?

join the chain as short as you can SS style on a vertical (or fixed) drop-out hardtail, depending on gear and chainstay length, that chain is going to be anything from too tight to use to too slack to stay on. there's your variance!
some riders (not you, granted) will want as short a chain as possible, the variance I've explained above can mean the difference between 2 links to that rider's set-up.

GW - Member
oh. FFS.

you seriously think every hardtail has the same length chainstays?

I do hope thats a tongue in cheek comment, if a chainstay is 17" long and you put the chain round the biggest front & biggest rear and add any number of links the chain will eb the correct length, the very same theory will apply to a chainstay that is 22" long.

GW - how do you set up yours?

Huh - and what does that have to do with anything? Yo still have not explained why big / big plus two links does not work in some cases.

yes I want a chain a short as possible which is why I set it up as I do. one link shorter and it would not go into first without straining the mech

I always had inner and outer plate, 3 roller/pins, equals one link. The half link chains tend to support that belief but I have never used one.

Not checked the instructions in a while now but recall that Sram supported the big to big plus 2 concept.

GW please explain how the chainstay length makes a difference on a hardtail when using the method suggested by TJ.

one chainlink comprising of just 2 plates

That's half a link

Big-Big + 2 rivets is the official recommendation from Shimano and SRAM (goes off to check KMC).
KMC helpfully suggest using the old chain as a pattern...hmmm.

It also happens to work.

Why all the fuss?

Only point worth debating is where to put the rear suspension to get max chain length position....it is not always at one end.

PaulD

If you use the big to big plus two links system on a 1x9 set up, it MAY leave you with too short a chain. This is because on a 2x9 or 3x9 etc you should never actually use the biggest chain wheel to biggest sprocket, whereas on a 1x9 you obviously will do. For a 1x9 set up feed the chain over the biggest sprocket over the chainwheel & actually through the mech, then tension the chain so you still have an S shape in the chain as it runs through the jockeys. TJ's photo above shows it as tight if not tighter than i would want to go & fitting a medium cage mech would leave you with a slightly more pronounced S, so mech length does make a slight difference too.

dicky boy - how can it leave you with two short a chain? the plus two links gives you enough slack to fit a mech, the big to big allows for the chainstay length. It cannot be two short and the shorter the chain the better so long as there is enough room for the mech

My pics show the same angle as the pinkbike recommended right chain tension

Tj/Avdave - re-read what I wrote.. take your times 😉

I have GW and it does not explain why big / big plus 2 links is wrong - especially as yo call half a link a whole link 🙂

Far too fast 🙁

that's ok, you have 5 months to work it out too.

GW - I have reeally tried to see your point and cannot.

"many suspension frames have too much chain growth for just 2 extra links or even 4"
Maybe from unsagged, but if you can work out where the effective chainstay length is at its longest and then hold it there then biggest-biggest + inner+outer links length overlap will work?

"on a hardtail chainstay length variance "
Eh?

"One chainlink is an inner and an outer link"
"big / big plus two links "
I see, Ive been thinking your 2 links are one inner and one outer
So youre setting up with 4 chain pins worth of length, when you could also use 2 chain pins of length (one of your chainlinks, rather than 2)

"one link shorter and it would not go into first without straining the mech"
I do with mine, they all seem alright

"MAY leave you with too short a chain. This is because on a 2x9 or 3x9 etc you should never actually use the biggest chain wheel to biggest sprocket, whereas on a 1x9 you obviously will do"
For 3x9 I wouldnt for crossed chain innefficiencies, but for (bash)2x9 I do go big-big. On short sharp up/down/up down type trails I leave the front mech alone and shift only with the rear
1x9 I go that short too?
How MAY it leave too short a chain?
"so mech length does make a slight difference too"
IF you set it up with excess chain like you describe, but if as short as will go with biggest-biggest + 2pins/rivets length, no?

Some 'knowledgeable' types making this much harder than it needs to be. TJ has got it right, it really ain't that hard.
1 link = 2 plates 😆 Bellend

on a 2x9 or 3x9 etc you should never actually use the biggest chain wheel to biggest sprocket

On a 2x9? Nonsense.

Anyone know the correct chain length for a 1x10? 😀

thanks Dickyboy.. you have answered my question.. 🙂