Chainline and directmount chainring offset?

Discuss light weight issues concerning mountain bikes & parts.

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Zak
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by Zak

Hi,

I have a newbie question. If I have a 1X crankset that with an directmount chainring with 6mm offset makes a 49mm chainline, will the chainline with a chainring with 3mm offset be 46mm or 52mm?

thanks :)

Steel4Real
Posts: 4
Joined: Sat Jan 07, 2017 9:25 pm

by Steel4Real

Zak wrote:Hi,

I have a newbie question. If I have a 1X crankset that with an directmount chainring with 6mm offset makes a 49mm chainline, will the chainline with a chainring with 3mm offset be 46mm or 52mm?

thanks :)


The chainline is measured from the center of the seat tube to the chainring (1X), or between the chainrings (2X, 4X), or the middle chainring (3x). Offset moves the chainring further away from the crank and closer to the seat tube.

Reducing the offset from 6mm to 3mm on a long-spindle (external bearing BB cup) crankset will result in a 52mm chainline. That's good for fatbikes, but your chain may want to jump off the large rear sprockets with a standard rear end.

There are also 0mm offset chainrings for short-spindle BB30 (or other internal bearing crank designs), or for cranks with adjustable direct mount offset via spacers.

There is a little information at the Wolf Tooth site:

https://www.wolftoothcomponents.com/pro ... ram-cranks

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Zak
Posts: 781
Joined: Sun Sep 10, 2006 6:43 pm
Location: Copenhagen, Denmark, Earth, Universe
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by Zak

Thanks :D .

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