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  1. #1
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    Possible chain line issue

    I just went 1X10 on my bike and love it. I have noticed that my chain line in 1st gear is really offset. The optimal chain line seems to be 7th gear.

    Do I need to worry about moving the crank over or putting spacers on the chain ring to line up with gears closer to the middle of the cassette? I noticed there is a spacer on the right side bearing cup that could be moved over the left side to get me 2.5mm. Also noticed that the RH cup was not pressed in all the way when the bike was built. Corrected already. Worth maybe 1.5mm. Well what do you all think? Am I crying before I'm hurt or is it a genuine concern? See pics below.











    Thanks, Friz

  2. #2
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    The chain line does look a bit off center of the cassette in the picture but you should measure to see for sure, there is a sticky in the SS forum for that I think. If it is where you think it is then I would definitely move it over by switching the drive side spacer to the other side.

  3. #3
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    We have been testing a stock Stache 8 at twentynineinches.com and I took a measurement from the outside edge of the down tube to the inside edge of the 38t chainring and it was right at about 1". I have attached a photo to help clarify what I am trying to explain. Looks to me like the chainline in your pic is likely off from what is should be. If you're going to stay with that 1x setup, I think I would even go 2mm to 3mm further inward than what is illustrated in the pic (JMHO).

    FWIW, I am building up my own Stache 8, and I used a FC-M760 XT crankset with three chainrings. Interestingly, it measures the same measurement (about 1" from frame to inside edge of the down tube to the inside edge of the middle chainring).

    Possible chain line issue-img_2619aaa.jpg

  4. #4
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    If you have chainring to chainstay clearance you can move the spacers around. Looks like a Shimano crank so you can move the spacer to the other side or put a thinner spacer on each side.

  5. #5
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    Re: Possible chain line issue

    Ideally the chain should be straight in the middle of the cassette, but moving the spacer will give you 2,5mm. You will be close, probably straight when in 6th

  6. #6
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    I'm not sure if people do this or not, but you can also put washers in between your chainring and chainring tabs to move it ever so slightly inward. Also make sure you're running your chainring in the middle ring position, on the inside of the tab that used to hold the middle and outer chainrings.

  7. #7
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    The consensus seems to be to get the chain line as straight as possible to the middle of the cassette. For my bike this involved using two bearing cup spacers on the driveside and putting the chainring on the inside (middle) position of the crank.

    Though I think you should take into consideration what gears you use most. With my riding I use the highest as frequently as the lowest, so the middle makes sense. However, if you spend a lot of time in lower or higher gears it makes sense to favour whichever you use - i.e. line up with 5 in the rear if you use low gears more or 6 if you use high gears more. 7 seems a little extreme unless you use the low gears very infrequently.

  8. #8
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    Thanks for all the suggestions. I guess the consensus is that chain line does matter. I dug up a few 5.5mm spacer bushings to see where that would put the chain line and it seems to be about right.


  9. #9
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    Looks pretty cool too

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