Surly Mr. Whirly Crank Arm Sets are sold without spider or spindle for complete customization.
- Chainrings and chainring mounting bolts sold separately
- Build it to be the crank you want: single, double, triple, or trials
- Arm sets include non-drive side bearing adjust cap, drive side PTO bolt & cap, and two sets of spider mounting bolts (one short for spider mounting only, and one long for mounting spider with granny ring)
- Outboard-style bearings must be purchased separately; use Shimano Mountain, Race Face X Type, or FSA MegaEXO
- Forged and machined 7075 aluminum
- Available Crank Lengths: 165, 170, 175, 180, 185mm