Introduction
This guide shows how to install a chainring on a crankset which has adjustable chainline via a 1mm and 2mm spacer which sit on either side of the chainring.
Tools
Parts
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Start with identifying what offset chainring you have. Is it a -8mm "non-boost"? or -5mm "boost" offset?
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-8mm "non-boost" will work with 142x12, 150x12, 157x12 and 148x12 depending on how the ring is spaced.
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-5mm "boost" will only work with 148x12 spacing
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Note the direction which the chainring will install on the crank. The offset should be going towards the frame and not away from it.
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Non-boost 142x12, 150x12 and 157x12 will use -8mm offset ring with 2x chainline spacers on the crank first. Then the chainring and lockring
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Boost 148x12 will use -8mm offset ring on crank arm first. Then install 2x chainline spacers and lockring
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Boost 148x12 when paired with -5mm offset ring will have 2x chainline spacers installed on the crank first. Then install chainring and lockring
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The chainring spacers can also be used to fine tune and optimize chainline to your preference or your bikes specific needs.
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Thread on lockring with spacers in correct location for chainring offset and rear hub spacing
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Tighten lockring to 30Nm (Snug + 90 degrees)
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If setting up a configuration where the lockring is tightening against a spacer, ensure that the spacers are sitting fully in the grooves of the mounting location so the lockring is fully compressing the system.
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