Chain Line measurement.

kevin881

New member
Okay so I am clueless on this, but I am not that experienced at building bikes, so maybe this is a dumb question.

I am putting modern day parts on the newly painted Yo. I have RaceFace Atlas cranks. BB installed with no issues, and used spacers for the right BB shell size.

However, the cranks come with another set of spacers to adjust for the "chain line measurement." Its either 48, 49 or 50mm. I am clueless on this. The parkbike tool site doesnt seem to elaborate on it at all either.

Can anyone point me in the right direction? Thanks.
 

kevin881

New member
thanks for the useful link Zook. I bookmarked it. Great info, and I now have a full understanding of what the chainline measurement is.

Problem is that he seems to indicate that to some degree on geared bikes, the measurement is a bit of preference depending on use, or seat tube diameter.

So, instead of measuring and getting totally A.R. about it, it seems that for a 27 speed on a Yo the chainline will be on the higher end, at 50. Both the larger seattube and the 9 gears on the cassette (greater distance to middle gear) would point in that direction.... am I wrong to assume this?
 
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