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I need skills
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Discussion Starter · #1 ·
This is my first 12 speed drive train.

When in the lowest gear it sounds like my chain is crossed. My Wife and son have 12 speed and their bikes do not make this noise. I have a 34 in front and wife and son have 30 and 32.

I have a b-gap gauge and that is fine.

Does the front chain ring have any thing to do with this sound? Any ideas?
thanks,
Charlie
 

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Proper chainring for your bike rear? If you have a standard chainring on boost bike, could possibly make for some of what you're describing when in smallest cog.

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This is my first 12 speed drive train.

When in the lowest gear it sounds like my chain is crossed. My Wife and son have 12 speed and their bikes do not make this noise. I have a 34 in front and wife and son have 30 and 32.

I have a b-gap gauge and that is fine.

Does the front chain ring have any thing to do with this sound? Any ideas?
thanks,
Charlie
Just so we are clear -when you say lowest gear you mean first gear (low gear). The largest cog.

It could be derailleur adjustment. I have a 12 speed, there is a little bit of noise in low gear (1st gear) but nothing alarming. More audible than lets say the center of the cassette.

It it alarmingly loud, our just louder than what may be normal?

What bike is yours vs. the family's bikes? Maybe yours is different enough from their bike that the chainline is just different, or different components.
 

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I need skills
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Discussion Starter · #4 ·
Just so we are clear -when you say lowest gear you mean first gear (low gear). The largest cog.

It could be derailleur adjustment. I have a 12 speed, there is a little bit of noise in low gear (1st gear) but nothing alarming. More audible than lets say the center of the cassette.

It it alarmingly loud, our just louder than what may be normal?

What bike is yours vs. the family's bikes? Maybe yours is different enough from their bike that the chainline is just different, or different components.
regarding above post. The drivetrain came with the bike (2019 Jeffsy).

The noise is not alarmingly loud, just surprising as I don't hear it on the other bikes.
yes, largest cog.

Wife has GX on a trek ex8
Son has NX on stumpjumper
I have GX on jeffsy.

I counted the outer plates on the chain. The drivetrain with the 32t has 58, my 34 has 59 (so chain length should be fine).
 

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...I counted the outer plates on the chain. The drivetrain with the 32t has 58, my 34 has 59 (so chain length should be fine).
That alone doesn't show it's correct. Proper chain length is also affected by chainstay length and rear suspension kinematics, both of which will differ between bikes.
 

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Is chain routed correctly thru derailleur? That would make a sound, but likely in all gears...

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Have you looked down at how the chain is positioned when in your largest cog? I test rode a Fuex EX 9.7 with Eagle and was surprised how the chain line was. Way more offset than my 1x10 setup. I did notice some chain line noise, more than my 1x10, but didn't think it was outlandish. When I focused on my riding, the noise was not apparent.


I'd just ride it. Focus on your ride, the noise goes away.
 
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