Owner's Manual

16
Thorn lightweight mini eccentric (Mercury models only)
In order to save weight, the new eccentric had to be smaller in diameter.
Being smaller, means that it can adjust little more than half a link. When no more adjustment can be
made with the eccentric, a new chain must be fitted.
By choosing one of the ideal chain ring and sprocket combinations, the service life of the chain is
maximised.
A B C
A has all adjustment remaining.
B has half adjustment remaining.
C has no adjustment remaining.
Note that the eccentric should be rotated in a clockwise direction so as the thin part of eccentric is
at the bottom of the shell, this helps prevent ingress of water through the slots.
The 4 M5 screwson the bottom bracket must be removed at least once every year and fresh copper
slip should be applied to the threads. If the bike is used in harsh conditions, such as on salted roads
or beaches, re-lubrication, with copper slip, must be more frequent.
The 4 x M5 screws need to be tightened and loosened in a particular sequence (please see diagram
below).