This simple disk bolts to the Kris Holm Spirit ISIS cranks - you slip the axle
bolt onto the Rollo Disk and then tighten the axle bolt into the crank. It turns
the Spirit cranks into superb flatland cranks by enabling a huge increase in
stability for crankrolls, without any need to produce specialized flatland
cranks. Sold in Pairs..
The Rollo Disk should be installed after crank installation. If you are installing both cranks and the Rollo Disk, install the cranks first, then unscrew the crank bolt and install the Rollo Disk.