This chain is used on a standard 3 speed Brompton folding bike (with 50 tooth front chain ring) with either the 13T or 14T rear sprocket This chain is also used on a 2 speed or 6 speed Brompton folding bike with reduced gearing (44 tooth front chain ring) where the largest rear sprocket is 16 tooth (used on the two speed and BWR 6 speed wheels) or 15 tooth (as used on the old Sachs/SRAM 6 speed rear wheel) The chain comes complete with SRAM PowerLink for easy chain joining The table below shows all the chain ring / sprocket / chain combinations. Having the correct length is important - it will help stop the chain jumping off when folding (as the chain tensioner keeps it correctly taut) If you are changing your chain we also recommend changing the sprocket(s) - changing just the chain will result in the chain wearing quicker and the chain may also slip on the old sprocket(s) when under load. The chain is marked: SRAM PC-10 Tools Required: To remove your old chain you could need a chain tool (it depends upon whether the old chain had a powerlink) - this will destructively remove all chains, or a pair of master link pliers (to remove the PowerLink to split the chain) Brompton Q part code: QCHAIN098DR Old Brompton Q part code: QCHAIN98DR Brompton part number: 9022038 Brompton chain length summary Chainring One Rear Sprocket Two Rear Sprockets 54 tooth 12 or 13t 100 Links 12/16t, 13/16t or 13/15t 102 Links 50 tooth 13t or 14t 98 Links 12/16t, 13/16t or 13/15t 100 Links 44 tooth 12t, 13t or 14t 96 Links 12/16t, 13/16t or 13/15t 98 Links