front ring on a boardman comp

alexander flint
alexander flint Posts: 20
edited August 2011 in Road beginners
Does anyone know what is the smallest front ring you can put on a boardman racing bike.
Thanks

Comments

  • Pross
    Pross Posts: 43,463
    It will depend on what type of chainset you have rather than the bike. It also depends on the difference in size between the two chainrings with 16 teeth being generally considered the biggest gap that a front mech can cope with.

    If using a compact then the smallest is usually a 34. On a traditional double you can get a 38t inner ring if 130 BCD (the diameter between bolt holes) but I think 39t is the smallest for 135 BCD that Campag used to use.
  • blackhands
    blackhands Posts: 950
    Pross wrote:
    It will depend on what type of chainset you have rather than the bike. It also depends on the difference in size between the two chainrings with 16 teeth being generally considered the biggest gap that a front mech can cope with.

    If using a compact then the smallest is usually a 34. On a traditional double you can get a 38t inner ring if 130 BCD (the diameter between bolt holes) but I think 39t is the smallest for 135 BCD that Campag used to use.

    BCD stands for Bolt Circle Diameter and is not the distance between bolts.
  • Pross
    Pross Posts: 43,463
    blackhands wrote:
    Pross wrote:
    It will depend on what type of chainset you have rather than the bike. It also depends on the difference in size between the two chainrings with 16 teeth being generally considered the biggest gap that a front mech can cope with.

    If using a compact then the smallest is usually a 34. On a traditional double you can get a 38t inner ring if 130 BCD (the diameter between bolt holes) but I think 39t is the smallest for 135 BCD that Campag used to use.

    BCD stands for Bolt Circle Diameter and is not the distance between bolts.

    I was trying to explain it in laymans terms as this is the beginners forum. It's hard to word it properly as 'bolt circle diameter' might not mean much so for clarity

    boltcircle.jpg

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