Spank's Single Speed Conversion Kit is perfect for anyone wanting to convert their HG splined rear wheels to single speed.Who's this item for: Riders who's rear wheels are using the HG splined freehub standard and want to convert their bike to single speed.Number of gears: One. One gear to rule them all!Weight: Not confirmed.Materials / construction: This kit features alloy spacers and a stainless steel 13T cog.Cog-tooth span: One single 13T cog.Freehub mounting style: HG splined.Other component compatibility: This will suit all HG splined freehubs. Pros: Simple, effective solution for a single speed setup.Cons: If your bike doesn't have an eccentric bottom bracket or horizontal dropouts or you want to use this kit with a dual suspension bike you will also need a chain tensioner.