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    Is the low clearance between the non-drive crank arm and the frame a concern? If yes, would bottom bracket spacers fix this problem?


    Working on a project and when I installed the cranks I noticed how close the non-drive side crank arm was to hitting the chainstay. Only a couple of mm at most. Drive-side doesn't have this problem, it has maybe a cm of clearance give or take. BB shell for the frame is 68mm which is what I got, recommended spindle length for the BB by the cranks was 110mm which I got (BB is velo orange English threaded)

    Should this low clearance be a concern? If yes, would adding bottom bracket spacers fix this issue?

    Ignore the noise you hear, just the pedal hitting a tire I have hanging from the stand. Thank you

    Is the low clearance between the non-drive crank arm and the frame a concern? If yes, would bottom bracket spacers fix this problem?
    byu/TinkyThePirate inbikewrench



    by TinkyThePirate

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    12 Comments

    1. oolij on

      Wondering if frames bend at all laterally during turning? If there’s any momentary warping/bending of the frame during left hand turns could this crank possibly graze the chainstay?

    2. 3wbasie on

      I think you’ll be okay I’ve had tight clearances with cranks and been okay in the past but if you’re worried about it you could always get a longer bb

    3. Statuethisisme on

      Is the BB a cartridge type that has two separate housings for the DS and NDS? If so check if it is assymetric, and can thus be reversed to potentially move the cranks towards the NDS.

      If not, you will likely have to find an assymetric BB or use a slightly longer spindle, and put up with the uneven spacing.

      Spacers will likely not help you at all, as typically the BB must be designed to use them, and generally they only go on the DS in place of chain guard mounts or E-Type derailleur mounts. The NDS is usually not the fixed side.

    4. Lazar4Mayor on

      Looks fine. I tend to discourage the use of unspecified spacers because they can and often do result in crank installation errors and preload issues.

    5. Imazagi on

      This looks too tight tbh. When climbing out of the saddle, the BB area will probably flex enough to make contact. You can put a foot against the BB on the driveside and look if the chainstay makes contact.

    7. oolij on

      How do you feel about shorter cranks length? That could give you a little more wiggle room but also would bring other changes to the ride/fit

    8. ride_whenever on

      This is really borderline, it’ll depend on the frame flex under load. I had similar clearance and could just make it touch when really pushing.

      Easiest thing is just take 1/2mm off the back tip of the crank arm with a file. Correct thing is longer bb axle, but you could potentially gain chainline issues. You may be able to do something with spaces but generally not with cartridge BBs, and running the cranks offcentre has some weird effects.

      I went for option c and dinged the chainstay in a smidge with a ball peen hammer, but that’s 100% dumb.

    10. Key_Beautiful1745 on

      Basically to parrot what other have said, you need to actually go test it out and see if it strikes under the most intense biking you would do. Put a piece of tape there or something to protect the paint.

      I had a similar situation with wide tires that would only rub when I was out of the saddle. I didn’t notice for at least 2 weeks since all my riding was casual to that point.

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