If you are looking for a durable single speed cog

7mm is used on the DBCOIL

Each leg will fit into a groove inside the lower post

Which wheel: Greg uses it front and rear for his downhill bike

leverage and comfort

Fox Shox Rear Shock Mounting Reducer Kit - Alloy - 6mm x 38.6mm - 1.52 Inch PLP|Riding Style If you are looking forFox 5 piece reducer kit. This polymer reducer kit replaces the old DU bushing and aluminium reducers for less friction and longer life. Features: This design can reduce friction up to 50% over the older designs. O rings keep the elements out. The is a huge improvement over previous designs and will prolong the life. Tool free! New bushing installs by hand. Please note: Your frame's manual will tell you exactly which size you need. Some frames use