[Closed] Chain line on 1x10

This isn't an answer as such, more an add on to your query (not very helpful!). I'm currently running a 3 x 10 set up on the middle chain ring as a result of a cock up changing the front deraileur cable and getting sick of it and removing the whole lot.

I'm considering getting one of these thin fat single chain ring set ups that everyone is raving about, but how is it supposed to sit in relation to the rear cassette, in line with the central sprockets I'm assuming?

Your original set up, were you running a bash guard as well as the 2 chain rings?

Im running a works 32t up front on a xtr m970 crank with 11-36 at the rear. The chsinline is terrible and you can actually hear the chain gripping the front ring in the largest 2 rear gears. This is without a spacer on the driveside bb aswell.

No bash guard, I've got slx m675 double cranks, not designed or an outer ring!
Hence the chain rings are aligned to maximise the two rings for positions.
I can imagine for a lot of my riding I will probably be using the biggest cogs on the back.

On a triple the rings are set out with the centre exactly in the centre of the cassette, and the inner and outer are set 5mm either side. IIRC the midline spacing on most cranks is 50mm, hence the rings will be at 45, 50 and 55mm.

On a proper double (as opposed to double + bash which is basically a triple) you have the same midline, but the rings, still 5mm apart, will be either side of the middle - hence at 47.5mm and 52.5mm

So end result - 1*10 using the middle of a triple, the chain line will be straightest in the middle of the cassette.

On a double, you'll be 2.5mm off, either to the low or high end depending on whether you use inner or outer ring positions. Which in turn might be dictated by the size of the single ring you use, but almost certainly will be the outer unless you're intending to run a very small inner.

This 2.5mm will make sod all difference in practice, but if you're obsessed and have an external bb you can adjust the position of the bb spacers to take that 2.5 mm back. Means your pedals won't be exactly spaced either side but you won't notice that either.......

Naffa - is the m970 a triple, and if so are you running inside of the mounting tabs, or outside?

Thanks for that, it explains a lot. I guess I'll consider getting the thin fat chain ring and see how it goes. I've only ridden my current set up twice at Dalby in appalling conditions and that place has a habit of making everything on your bike sound like it's grinding itself to pieces after a while because of the sandy mud.

In first gear especially it sounds like everything is rubbing way too much, but thinking about it logically, it would surely be the same on a proper 1 x 10 set up, so my bodged (i.e. cheap) effort will have to make do. I guess I was wondering whether the drive chain was slowly rubbing itself to pieces!

No doubt that the lowest gear (big, innermost rear cog) seems to be the least optimised. It's where the chain is most crossed and hence will be the one most prone to causing grinding. In fact the smallest, outermost cog will be equally crossed but when you're in that cog you're usually doing 20+ mph and wind noise and clattering over rocks etc. covers the grinding up. You use the lowest gear when you're doing 4mph uphill where the only sound to cover up the grinding is your heavy breathing!!

I'll try it as it is with my current set up.
I might try some spacers to push the chain ring inwards a bit to help with the chain line!
If it's not good, I'll have to look at different cranks.
Great knowledge 'theother' helped explain a lot

I'm running a 1x10 with the following:

Zee single specific crank.
RF Narrow Wide 32T.
XT 11/36 cassette.
KMC gold chain.
XO short cage clutch mech.

I do experience some noise in the lowest (largest) gear, however I didn't experience this with a 1x9, I know I have an extra gear but I thought the spacing on the 10 speed cassette was narrower but not as wide as the 9 speed, if that makes sense? I assumed 10 speed would be just as quiet as 9 speed, plus I was using a guide too.

I assumed the chainline would be the same running either 9 or 10 speed.

Still, I much prefer my current set up and it looks cool too 🙂

@theotherjonv, the ring is in the inside of the tabs. Funny thing is that running 1x10 with a cheaper triple crank and 32t non nw ring and the same cassette I didnt have any issues

I do think the nw rings are noisier than a standard ring, where they have thicker teeth there's less space for the chain to leave the ring at an angle, hence they seem to rub more at the extremes of the cassette. Trade off for the benefits that I'm happy to accept.

Tojv I think youre probably right there. Looking closely it is the wider teeth that cause the noise and slight chain pick up.

The issue 2x cranks is known by the ring manufacturers. It seems whatever you do will be less than satisfactory and it is not just a simple bolt on upgrade in the case of 2x cranks. Why none of them mention this or offer a solution is beyond me really. I had to ruin the granny ring and bolt to get it off, two mangled bolts are still stuck fast so I can't go back and now have to spend more to try and sort it out all the while loosing sunny riding time. Rubbish