Swapping Chain rings

Mobipedal Posts: 5
edited April 2018 in Workshop
Hi there,

I have a Shimano Ultegra 6800 chainset with 52/36 chain rings (with the four armed spider) if I put some 50/34 chain rings on will the bolts line up with my existing cranks!

Thanks for your help!


  • redvee
    redvee Posts: 11,922
    If you buy chainrings with the right BCD
    I've added a signature to prove it is still possible.
  • svetty
    svetty Posts: 1,904
    Assuming they are 4 bolt rings then yes.

    You may need to lower the front mech a couple off mm and possibly shorten the chain.....
    FFS! Harden up and grow a pair :D
  • Thanks for the replies guys. What does BCD mean?