Increase your tire footprint by going MWOD. Truly a Surly original.
The two rings are bolted to each other; the combo then bolts directly to the 58mm bolt circle on Mr. Whirly cranks (hardware included)
Converts the Mr. Whirly crankset into an offset mountain double crank which allows for extra wide rear tire and rim combinations while avoiding chain-on-tire rub, e.g., 4.7" tires on 82mm or 100mm rims
Smaller rings are stainless steel; bigger rings are aluminum
Granny and middle rings are repositioned to the outer two spots on the crank. This increases tire clearance at the chain without increasing Q-Factor or sacrificing the essential lower gears