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Upgrading to 12s

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Old 02-22-22 | 03:27 PM
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Upgrading to 12s

Hello , i have a non-boost frame and in the next upgrade i want to convert from deore 2x10 to the 1x12 setup.
for the conversion i'm going to use those components
- suntace mz90 (12s cassette whitout the micropline or xd hub)
- my currently derailleur Shimano Deore M4100 (i read somewere in the web that derailleur has the same pulling ration of any 12s derailleur , basically with an extended hanger should do the trick).
- SRAM NX 12s as the right shifter.

but my main problem in the chainline , my actual crankset is deore 4100 2x10 (26-36) with a chainline of 48.8.
can a crankset with the chainline of 52 should do the trick?
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Old 02-23-22 | 03:39 PM
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Have you confirmed that the SRAM shifter will work with the Shimano RD? I know there is some serendipitous Shimano/SRAM cross-compatibility for a few specific combos, just not sure which.

I know 11 and 12 speed Shimano MTB RDs have the same pull ratios, not sure about 10. Goatlinks or some other extended hangar can work, but it depends how much you are trying to stretch it. The other issue is that the 11 and 12 speed cassettes are slightly wider than the 10. Does the Deore M4100 have enough horizontal movement for that?

As far as chainline, I can tell you from my experience putting an 11 speed cassette (same width as 12) on an HG hub on a non-boost wheel that my 52mm chainline was far too outboard. I had to use a 7mm spacer to get it centered on the cassette. Much less than that and I was dropping the chain on the biggest cog if I backpedaled. The issue is that the 11-12 speed cassette is wider, and the extra width goes inboard. Plenty of people just run these with lousy chainlines, though.
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Old 02-28-22 | 01:46 AM
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Don't mess around with the derailleur hack. There's more to compatibility than cable pull. Your current derailleur was never meant to clear that large a cog. A wolf link will make it clear but it will mess up the position of the derailleur to the rest of your cassette and it will shift like crap. If you're going to upgrade, do it to something that'll actually work well, in this case a Sram Eagle derailleur or some kind.

52mm should be the chainline with a boost hub, so your current chainline should be fine.
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Old 02-28-22 | 08:40 AM
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Originally Posted by cpach
52mm should be the chainline with a boost hub, so your current chainline should be fine.
He does not have a boost hub.

Edit: never-mind, I think you meant his 48.5mm chainline.

Last edited by Kapusta; 02-28-22 at 08:46 AM.
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Old 03-01-22 | 05:25 AM
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Originally Posted by Kapusta
He does not have a boost hub.

Edit: never-mind, I think you meant his 48.5mm chainline.
Originally Posted by cpach
Don't mess around with the derailleur hack. There's more to compatibility than cable pull. Your current derailleur was never meant to clear that large a cog. A wolf link will make it clear but it will mess up the position of the derailleur to the rest of your cassette and it will shift like crap. If you're going to upgrade, do it to something that'll actually work well, in this case a Sram Eagle derailleur or some kind.

52mm should be the chainline with a boost hub, so your current chainline should be fine.
Nope , i don't have a boost frame....
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Old 03-01-22 | 07:56 AM
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One thing to clear up about chainline: it means something slightly different with a 1x and 2x crank.

When talking about a 1x crank, it is measured to the actual chainring (or in the case of 3x, to the middle ring)

With a 2x crank, the chain line quoted in the specs is to a point halfway between the rings. So if you are running a ring just in the big ring position, the chain-line will be greater, and typically farther outboard than needed. In fact, after doing several of these conversions, I’ve found that the small ring position is usually a better chain-line with an 11 sp cassette, and pretty much perfect with an offset ring.

All that said, having a chain-line a little outboard of optimum is not the end of the world, and most new setups I see out there are in fact this way. The reason I believe has to do with frame and tire clearance.
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Old 03-04-22 | 02:34 PM
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Okay , the derailleur had to be replaced since this one i have can work max for 11s.
Also i noticed that all 12s works with 52mm chainline , do you guys think that can work even if i'am not using a boost frame?
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Old 03-04-22 | 02:49 PM
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Originally Posted by CrowSeph
Okay , the derailleur had to be replaced since this one i have can work max for 11s.
Also i noticed that all 12s works with 52mm chainline , do you guys think that can work even if i'am not using a boost frame?
All 12sp works with 52mm chainline? That makes no sense. It depends on the width of the rear hub (standard, boost, superboost….).
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Old 03-04-22 | 02:58 PM
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Originally Posted by Kapusta
All 12sp works with 52mm chainline? That makes no sense. It depends on the width of the rear hub (standard, boost, superboost….).
I mean , most of them seems to have 52mm chainline...
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Old 03-04-22 | 04:27 PM
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Originally Posted by CrowSeph
I mean , most of them seems to have 52mm chainline...
Let me repeat: Chainline varies with rear wheel spacing / hub width.
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