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Chain alignment issue on MTB

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Chain alignment issue on MTB

Old 07-08-20, 06:42 AM
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Chain alignment issue on MTB

Hi All
I am after some advice as I am having issues with my newly built hardtail. I have fitted a single narrow/wide chain ring (42T) up front paired with an 11 speed cassette on the rear. Fitted correct 11 speed chain and have a shimano deore xt derailleur.. The crank has all spacers on left hand side to bring chainring as close to frame as possible.
I set up the derailleur as far as end point travel is concerned prior to fitting the chain but now I've fitted chain I am major alignment issues resulting in chain being pulled off. It seems ok in gear 11/10/9 but as soon as it gets to 8th gear the chain is so out of line with the chainring it pulls chain off (chain ring too far out from frame. The obvious solution I guess would be to move crank spacers but they are already all on the left hand side meaning the chainring is already as close to frame as possible.
Now I will say that when fitting cassette I had leave the spacer nearest to the wheel hub out to enable to 11 speed to fit on hub, I guess this is normal...
Any help appreciated
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Old 07-10-20, 12:10 PM
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Check the chain length and also if the RD hanger is bent?
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Old 07-10-20, 09:04 PM
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Have you measured the real chain line amounts of both the cassette and the chain ring? Andy
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Old 07-10-20, 09:44 PM
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Does the chainring go on the other side of the crank arms?
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Old 07-10-20, 10:21 PM
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Originally Posted by bishop130771 View Post
The crank has all spacers on left hand side to bring chainring as close to frame as possible.
Why would you do this?

The object isn’t to get the chainring as close to the frame as possible. You want to have it line up in the middle of the cassette.

I’m not sure of your 11/10/9/8 issue. The chainline would get worse as you go to the 1st position, but I’m having a tough time understanding how a chainring would be that close and not hit the chainstay and have problem only 4 cogs over.

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Old 07-11-20, 03:57 AM
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You need to provide more details. What kind of BB, shell, crank, chainring, what type of spacers, on the spindle or the BB, which type of spider, which side of spider, dropout width, measured chain line at the chainring, etc.
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Old 07-11-20, 06:44 AM
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U want to be aligned with the 6th cog, that way your deflection to either side will be minimized...pics would be very helpful...
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