Genetic Tibia Track cranks.Traditional JIS square taper track crankset.High quality performance and finish at a reasonable price.Light and rigid forged alloy crank arms with polished CNC finish.Integral 5 arm track standard 144 BCD spider.Supplied with Silver Single chainring bolts.Sizes:170mm arms - Weight 643g (661g for powder coated)Recommended BB - JIS Square taper 68x107/110mm.Colours:Polished Silver, White powder coated or Black anodised.