Gusset Double Six 1-er Single Speed Conversion kitFeaturesSingle Speed adaptor kit for 8/9 speed cassette hubs.Pair of CNC machined aluminium spacers that look much sweeter than a bunch of washers to space out a 'Deep-tooth' single sprocket.CNC Cr-Mo cogs have wide 7mm base to avoid ripping into the cassette body.Built-in offset optimises chainline.Supplied with 12T or 16T 5/64" cog* and lockring.*Note: are suitable for narrow 5/64" (9 speed) chains.