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Thread: Crankset woes.

  1. #1
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    Crankset woes.

    Hey everyone! I have an issue with my Nashbar Cyclocross frame. I purchased a Truvativ Elita 50-36 compact crank with integrated bottom bracket and the crank arms hit the chainstays! It looks like I'm going to need a different crank. Any suggestions? I plan on using 105 brifters and front/rear derailleurs so I'd like to keep a semi decent chainline. I might have to go square taper or ISIS since the chainstays are so wide in the rear. Does anyone have any suggestions to keep everything semi compatible? Thanks for all your help!

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    Check with Nashbar as their tech service may be able to make a recommendation. I had an older Trek MTB that had the same problem and required a 127.5 mm square taper bb to have the crank arms clear the very fat chainstays.

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    Looking at the Nasbar customer reviews, looks as though you are not alone with this issue, have a look here, http://www.nashbar.com/bikes/Product...2_173397_-1___ there are a few suggestions, but going ISIS or Square may be the best option in the end.

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    Switching to a non external system is a bandage solution. Anything above the proper length will result in very crappy chainline. The question is what cranks work with that frame, not what you can do to a crank that doesn't work and compromise chainline.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

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    The dude at Nashbar's tech support wasn't very helpful. I just want to finish this build and the crank is holding me up. Nashbar recommends nothing larger than 48t for the large chainring, but the clearance issue is with crank arms and not the chainrings themselves. Thanks to everyone who has replied up to this point!

  6. #6
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    Shimano designed their stuff to be a package, but Cross racers run a 46-38, on 130 BCD,
    and 46 - 34 when you drop to a compact 110..

    Of course there is lose the double and run a single chainring.. the middle of a triple is the right chainline

    centered over the middle of the rear cluster.

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    Quote Originally Posted by fietsbob View Post
    Shimano designed their stuff to be a package, but Cross racers run a 46-38, on 130 BCD,
    and 46 - 34 when you drop to a compact 110..

    Of course there is lose the double and run a single chainring.. the middle of a triple is the right chainline

    centered over the middle of the rear cluster.
    You missed the entire point. It's not the chainrings that are the problem, it's the crank arms that are hitting the chainstays.

  8. #8
    pmt
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    Can the OP post a picture? I'd like to see that.

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    IMG_1275.jpgIMG_1276.jpg

    The tip of the crank arm hits the chainstay. With a little frame flex they will definitely slam into the chainstay after a pedal stroke. I am still not sure what to do.

  10. #10
    Senior Member bikeman715's Avatar
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    What you need is a longer BB 's axle such as a 122 or 127.5 MM to move the crank away from hitting the frame. Which mean a different BB set up such as sealed BB carriage and a different set of cranks to go with it.
    bikeman715

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    Quote Originally Posted by USAF1C1X1 View Post
    Hey everyone! I have an issue with my Nashbar Cyclocross frame. I purchased a Truvativ Elita 50-36 compact crank with integrated bottom bracket and the crank arms hit the chainstays! It looks like I'm going to need a different crank. Any suggestions? Thanks for all your help!
    You might get by with the Truvativ EXP 26-36-48 triples that are available on Ebay for about 105 dollars. I am running one as a double on a mountain frame with 105 shifters with the inner 26 sprocket removed and it works just fine.

    This crankset has 76 mm clearance from frame center to inside of crank arms, or 152 mm crank arm inside to inside. If you have less than 152 mm outside width on your chainstays where the crankarms pass, these will work with no BB change.

  12. #12
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    I'd prefer to keep a 50-36 but I am running out of options. I wonder if the Nashbar compact crank works. I am surprised no one has had this problem with their frame.

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    Quote Originally Posted by USAF1C1X1 View Post
    I'd prefer to keep a 50-36 but I am running out of options. I wonder if the Nashbar compact crank works. I am surprised no one has had this problem with their frame.
    My guess is that none of the road doubles will give the clearance you need. The 26-36-48 I suggested is a mountain crankset, and they seem to share a wider crank arm spacing. You might get enough clearance from a road triple, but it would be very close. The closest gearing you will find in a road triple would strip to a 50-39. Hope you find a good solution for your build.

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    Well then it looks like I might end up getting a 48-36-26 and remove the lower chainring like you did. Does your Truvativ crank have an integrated bottom bracket?
    Last edited by USAF1C1X1; 01-13-11 at 01:57 PM.

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    Quote Originally Posted by USAF1C1X1 View Post
    I'd prefer to keep a 50-36 but I am running out of options. I wonder if the Nashbar compact crank works. I am surprised no one has had this problem with their frame.
    Go back and read #3 above and the link he gave. It's not a new problem; you might find a solution among the reviewers on the Nashbar site.

  16. #16
    Senior Member Mr. Embrey's Avatar
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    How long are the crank arms? Can you exchange for a set with shorter arms?

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    Quote Originally Posted by USAF1C1X1 View Post
    Well then it looks like I might end up getting a 48-36-26 and remove the lower chainring like you did. Does your Truvativ crank have an integrated bottom bracket?
    Yes, the same GXP bottom bracket you now have installed with your 50-36

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  19. #19
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    Thanks for the link. I think I might just stay away from the integrated bottom brackets to avoid more headaches. I did find http://cgi.ebay.com/NEW-SHIMANO-OCTA...item4cf3880841 though. Anyone know what size BB I might need to keep a semi decent chainline that would work with a road double FD?

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