Surly

OD Crank Arm Set for 100mm BB and Pugsley/170mm Rear

Surly designed the O.D. crankset to offer frame and tire clearance while maintaining a reasonable q-factor (pedal stance). Maximizing the distance between the chain and the tire is important on fat bikes such as our Pugsley and Moonlander, or if you're running really big tires and rims on some other bike (like the Krampus, for example). With normal cranks, wide tires on wide rims can rub the chain when in the lowest, or farthest-inboard, gear combinations. Like the Surly MWOD crank, the O.D. crank doesn''t just add a longer spindle to move the rings outboard. Rather, it does away with the big ring of a standard triple and moves the middle and granny rings to the outer and middle positions. This effectively moves the rings outboard without moving the arms outboard too. The O.D. is a simple, dedicated version of this idea. Neato!

• Forged of 7000 series T6 aluminum, the O.D. crank is a 2-piece, with spindle embedded inextricably in the drive side arm. 
• It''s a dedicated 2x, although its chainline is outboard a bit compared to standard mountain cranks, and it is 9 and 10 speed compatible. 
• This version fits 100mm bottom bracket shells and is offset for the Surly Pugsley and 170mm fat bikes (like the Salsa Mukluk) with 4" tires.
• Uses 24mm outboard bearing bottom bracket (Race Face X-Type, Surly, Shimano Hollow Tech II)
• Chainrings and bottom bracket not included