When increasing the width of the rear tire, you quickly find that chain interference becomes a limiting factor in the search for more tire girth. Without modifications to the drivetrain, the chain will rub against the outside edge of the tire when the bike is shifted into the lowest gears. For example, on a Pugsely with a standard 3 x 9 drivetrain, 82mm Rolling Darryl rims and 3.8 ̋ Nate tires, the chain will rub the rear tire in the lowest available gear combo. On a bike designed to crawl over the gnarliest terrain possible, the lowest gears are essential and cannot be limited.
The MWOD system is a set of two front chainrings (20/33t or 22/36t). The granny ring is mounted directly to the 58mm mounting holes of a Mr. Whirly crank arm and the middle ring mounts directly to the granny. This system eliminates the outer chainring from a standard triple and uses the available space to shift the granny and middle chainring to the old locations of the middle and outer chainrings.
MWOD chainrings convert your Mr. Whirly crankset into an offset mountain double crank, allowing you to run extra wide rear tire and rim combinations (4.7˝ tires on 100mm rims, for example, or 82mm rims on your Pugsley) while avoiding chain-on-tire rub. MWOD rings move the granny and middle rings to the middle and outer positions of the crank, effectively increasing tire clearance at the chain without increasing your Q-factor and without losing your crawling gears.
MWOD granny rings are stainless steel, the bigger rings are aluminum. The small ring bolts to the big ring, and the combo then bolts directly to the 58mm BCD mounting holes on Mr. Whirly cranks. They’re available in 20/33t and 22/36t.
Color: Natural Silver