A crank assembly for a bicycle comprising: an integrally formed unitary first portion having: a first arm having a first solid end and a first axial bore extending from said first solid end to a second end; and, a spindle extending substantially perpendicular from said first arm adjacent said second end, said spindle having a second axial bore extending into said first arm adjacent said second end, said second axial bore being arranged to intersection with said first axial bore, wherein said spindle extends from said first arm in a continuous non-segmented manner; and, a second portion, said second portion having a second arm having a third solid end and an third axial bore extending from said third solid end to a fourth end, said second portion being operably coupled to said spindle adjacent said fourth end; wherein said first arm includes: a curved first wall; a curved second wall opposite said curved first wall, wherein said spindle extends from said curved second wall; a third wall between said curved first wall and said curved second wall; and, a fourth wall between said curved first wall and said curved second wall opposite said third wall; wherein said curved first wall, said curved second wall, said third wall and said fourth wall define said first axial bore; characterised in that said curved first wall and said curved second wall have a first thickness and said third wall and said fourth wall have a second thickness, wherein said first thickness is substantially one-half said second thickness. an integrally formed unitary first portion having: a first arm having a first solid end and a first axial bore extending from said first solid end to a second end; and, a spindle extending substantially perpendicular from said first arm adjacent said second end, said spindle having a second axial bore extending into said first arm adjacent said second end, said second axial bore being arranged to intersection with said first axial bore, wherein said spindle extends from said first arm in a continuous non-segmented manner; and, a first arm having a first solid end and a first axial bore extending from said first solid end to a second end; and, a spindle extending substantially perpendicular from said first arm adjacent said second end, said spindle having a second axial bore extending into said first arm adjacent said second end, said second axial bore being arranged to intersection with said first axial bore, wherein said spindle extends from said first arm in a continuous non-segmented manner; and, a second portion, said second portion having a second arm having a third solid end and an third axial bore extending from said third solid end to a fourth end, said second portion being operably coupled to said spindle adjacent said fourth end; wherein said first arm includes: a curved first wall; a curved second wall opposite said curved first wall, wherein said spindle extends from said curved second wall; a third wall between said curved first wall and said curved second wall; and, a fourth wall between said curved first wall and said curved second wall opposite said third wall; wherein said curved first wall, said curved second wall, said third wall and said fourth wall define said first axial bore; characterised in that said curved first wall and said curved second wall have a first thickness and said third wall and said fourth wall have a second thickness, wherein said first thickness is substantially one-half said second thickness. a curved first wall; a curved second wall opposite said curved first wall, wherein said spindle extends from said curved second wall; a third wall between said curved first wall and said curved second wall; and, a fourth wall between said curved first wall and said curved second wall opposite said third wall; wherein said curved first wall, said curved second wall, said third wall and said fourth wall define said first axial bore; characterised in that said curved first wall and said curved second wall have a first thickness and said third wall and said fourth wall have a second thickness, wherein said first thickness is substantially one-half said second thickness.