Fsa gossamer pro bb386evo db chainsetone of the most exciting developments in road bikes is disc brakes these bikes require 135mm old rear hubs and frames however they also require specially designed cranksets with the correct chainlines for the best shifting performance fsa is introducing 135mm old cranksets in the high end sl k and gossamer model lines features material cold forged al6066t6 aluminium crank arms al7075 100 cnc chainrings monocoque crankarmspider chromoly chainring bo