CHAIN for a Brompton. When fitting new chain, the rear sprocket (in the case of a derailleur version, both sprockets) should be replaced: a worn rear sprocket will almost certainly cause the new chain to jump, and also to stretch prematurely. Do not use a connecting link to join the chain: make the joint by pressing in the rivet, and then freeing that link, using a chain rivet tool. subtext chain table CHAIN LENGTH. It is essential that this is correct. The chart below shows the number of links needed for different chainwheel and sprocket combinations available from Brompton. Chainwheel
ONE rear sprocket
TWO rear sprockets
54T
12T or 13T
100L
16T/12T, 16T/13T or 15T/13T
102L
50T
12T or 13T
98L
16T/12T, 16T/13T or 15T/13T
100L
48T
13T
98L
46T
13T
96L
44T
12T, 13T, 14T
96L
16T/12T, 16T/13T or 15T/13T
98L
Also, chain used on Bromptons is either wide (1/8") or narrow (3/32"). Use wide chain if either the chainwheel or the rear sprocket is "wide", as narrow chain will not fit. Most non-derailleur bikes have a wide (2.6mm – 3mm) rear sprocket (unless the sprocket has been changed), so wide chain must be used. Certain derailleur bikes (usually those where a derailleur was retro-fitted) will have a chainwheel with wide teeth (2.5mm – 2.7mm), and (unless you choose to fit a new narrow chainwheel), such bikes also need wide chain. Maximum pin length for wide chain on a Brompton is 8.5mm. Narrow chain should be used on a 1-spd or on any derailleur-equipped Brompton where the front chainwheel teeth are narrow (2.0mm – 2.25mm). Max. pin length is 7.3mm.
CHAIN for a Brompton. When fitting new chain, the rear sprocket (in the case of a derailleur version, both sprockets) should be replaced: a worn rear sprocket will almost certainly cause the new chain to jump, and also to stretch prematurely. Do not use a connecting link to join the chain: make the joint by pressing in the rivet, and then freeing that link, using a chain rivet tool. subtext chain table CHAIN LENGTH. It is essential that this is correct. The chart below shows the number of links needed for different chainwheel and sprocket combinations available from Brompton. Chainwheel
ONE rear sprocket
TWO rear sprockets
54T
12T or 13T
100L
16T/12T, 16T/13T or 15T/13T
102L
50T
12T or 13T
98L
16T/12T, 16T/13T or 15T/13T
100L
48T
13T
98L
46T
13T
96L
44T
12T, 13T, 14T
96L
16T/12T, 16T/13T or 15T/13T
98L
Also, chain used on Bromptons is either wide (1/8") or narrow (3/32"). Use wide chain if either the chainwheel or the rear sprocket is "wide", as narrow chain will not fit. Most non-derailleur bikes have a wide (2.6mm – 3mm) rear sprocket (unless the sprocket has been changed), so wide chain must be used. Certain derailleur bikes (usually those where a derailleur was retro-fitted) will have a chainwheel with wide teeth (2.5mm – 2.7mm), and (unless you choose to fit a new narrow chainwheel), such bikes also need wide chain. Maximum pin length for wide chain on a Brompton is 8.5mm. Narrow chain should be used on a 1-spd or on any derailleur-equipped Brompton where the front chainwheel teeth are narrow (2.0mm – 2.25mm). Max. pin length is 7.3mm.