Bike Chain; Maintenance Of Bike Chains - Bosch Drive Unit Speed Manual Original

20 Bike chain

There are two types of bike chain:
• A wide bike chain (½ × 1 / 8") for hub gears and
• A narrow bike chain for derailleur gears. These are
available in different widths, depending on how
may sprockets are on the cassette. Only use chains
that are approved for precisely the number of
sprocket wheels on your bike.
› Clean and lubricate your bike chain regularly.
› To prevent premature wear of the bike chain when
using derailleur gears, select gears that keep the
chain skew as marginal as possible.
To check the wear in the bike chain, proceed as follows:
› Take the section of the chain that rests on the front
chainring between your thumb and forefinger.
› Pull the bike chain off the chainring. If the bike
chain can be lifted by a significant amount, it is
worn and must be replaced by a new one.
› With hub gears, the chain tension must be adjusted
so that vertical play of one to two centimetres is
present in the unsupported chain span between the
chainring and sprocket wheel.
To take up the slack in the bike chain, proceed as follows:
› Loosen the rear wheel nuts.
› Pull the wheel back into the dropouts until only the
permissible amount of play is present in the bike
chain.
› Tighten all screw connections carefully clockwise.
40 I General User Manual
Tighten all screws to the prescribed torque as other-
wise screws could shear off and components could
come loose or detach altogether (see ➠ Chapter 30
"Technical data").

20.1 Maintenance of bike chains

Bike chains are wear parts. Bike chains with hub gears
wear out after roughly 3000 km, and after roughly
2000 km with derailleur gears.
If the bike chain is worn, it can break and cause a
crash. If your bike chain is worn, have it replaced by
your specialist cycle shop before using the bike again.