38 I General User ManualCleaning› Whenever possible, avoid using cleaning agents onthe chain. If you use cleaning agents, such as rustremover, this may wash lubricant out of the chainwhich could lead to malfunctions.› The chainrings and sprockets should be cleanedregularly using a neutral cleaning agent.› You should clean the derailleur and lubricate themoving parts (mechanism and rollers) at regularintervals.19.2 Hub gearsThis User Manual describes the handling of typical, com-mercially available gear-shift components of a gear hub ona city or trekking bike. For other components, refer to theseparate information or enclosed instructions.If you have questions on installation, adjustment, main-tenance and operation, please consult a specialist cycleshop.If the hub is mounted on the frame, the correct fix-ing washers must be used on both sides and the hubnuts must be tightened to the prescribed torque (see➠ Chapter 30 "Technical data").If the fixing washers are used on one side only or thehub nuts are tightened incorrectly, the hub may mal-function: It could rotate. This could cause the shiftingcable to pull the handlebar to one side and cause aserious accident.The gears can be changed when the pedals are turn-ing. Very occasionally, the hub may produce a harm-less noise which is caused by its internal cogs andstop notches.If you encounter resistance when turning the wheel,the brake pads will need to be replaced or the hubwill need to be lubricated. This should be done by aprofessional bike workshop.If the chain jumps off the the sprockets when you areriding, the slack in the chain must be taken up imme-diately. If there is no further scope for adjustment, thesprockets and chain must be replaced.19.2.1 Operating the hub gears19.2.1.1 Shimano 7/8-speed shift lever› Turn the twist-shift lever to select all 8 (7) gears.• Increasing pedal force (increasing resistance)➞ indicator towards 8 (7)IndicatorDisplayRevo-shift lever• Decreasing pedal force (decreasing resistance)➞ indicator towards 1These instructions on operation of the Shimano twist-shiftgrips also apply for other makes of twist-shift grips.
