Bad boost chainline
 

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Bad boost chainline

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Just fitted a new chainring, chain and cassette to my pace 529. The chainline looks far from ideal and in the top two gears it sound awful from chain and chainring meshing. Not sure why it's so bad.

KMC x12 chain

Sram eagle chainring and gx mech

Garbaruk xd cassette

Thinking about it now, it was a bit noisy with the old full SRAM set up but not this bad. Perhaps the KMC chain is less optimal with a SRAM chainring? Or the chainline is so bad that no combination would make it run nicely.

I've ordered a non-boost chainring as it seems like the most obvious fix and there is plenty of clearance to play with. But it's annoying since it should be optimised for boost.

See video for horrible rumbling sound.

Just wondering if I'm missing anything obvious that may be causing it or if it's just a bad combination of parts and frame.

https://imgur.com/a/xjVHSQ5


 
Posted : 22/12/2024 5:58 pm
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Pretty sure Garbaruk recommend against the use of KMC chains

https://www.garbaruk.com/12-speed-xd.html?category=11


 
Posted : 22/12/2024 6:05 pm
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Ah thanks onzadog, I hadn't spotted that. I'll have to pick up a SRAM chain in that case. Hopefully it solves the chainring rumbling too.


 
Posted : 22/12/2024 6:30 pm
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I run 11 speed with KMC on garbaruk.cassette and it works. It might be making a contribution towards your noisy drive though.


 
Posted : 22/12/2024 6:37 pm
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Is the chainring offset correct? My Orange had a -3mm on but runs much better with a -6mm on.


 
Posted : 22/12/2024 7:19 pm
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My Moxie is the same. Being a boost axle, I went for the usual -3mm chainring and it didn't work great. Pipedream's site info was a little vague, but seemed to suggest running a non-boost ring/49mm chain line unless you had a large or oval chainring. So I went -6mm and it now works much better.

Just generally with chains on SRAM drive trains though, I'd strongly recommend the X01 chain. Expensive - twice the price of the GX, but last more than twice as long and generally better in all ways.


 
Posted : 23/12/2024 12:40 pm
davros, volksman, volksman and 1 people reacted
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Thanks all, 6mm offset ring arrived so I'll fit that and see. Screwed myself over with a combination of incompatible parts. Can't use a Shimano chain on the sram chainring. Can't use a KMC chain on the garbaruk cassette. I should have kept it simple (facepalm emoji)  What a bozo!


 
Posted : 23/12/2024 7:45 pm
volksman and volksman reacted
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Had a look at the specs and there it is

Screenshot_20241223-201506


 
Posted : 23/12/2024 8:19 pm

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