Bosch BULLS 650-185, Operating Instructions Manual

Page: 157 / 238

156
Cleaning and servicing
7.5.9.1 Checking the derailleur gears
The chain is tensioned by the rear derailleur
in
ebikes
with derailleur gears.
1 Place the
ebike
on stand.
2 Check to see if the chain is sagging (visual
inspection).
3 Gently press the rear derailleur forwards to
check whether it moves and whether it goes
back into position by itself.
 If the chain is sagging or the rear derailleur
does not go back into position by itself, contact
your specialist dealer.
7.5.9.2 Checking the hub gear
In the case of
ebikes
with a hub gear or pedal
brake, the chain or the belt is tensioned by a
eccentric bearing in the bottom bracket axle.
Special tools and specialist knowledge are
required to tension the chain. Contact specialist
dealer.

Remove the chain guard on
ebikes
with a
full
chain guard.
1 Place the
ebike
on stand.
2 Check the chain and belt tension in three or
four positions, turning the crank a full
revolution.
Figure 140: Checking the chain tension
 If the chain or the belt can be pushed more than
2 cm, the chain will need to be re-tensioned.
Contact specialist dealer.

If the chain or belt can only be pushed up and
down less than 1 cm, you will need to the chain
or belt slightly. Contact specialist dealer.
 The ideal chain and belt tension has been
achieved if the chain can be pushed between a
maximum of 10 and 15 mm in the middle
between the
rear gear
and the
chainring
. The
crank must also turn without resistance.
7.5.10 Checking the
drivetrain
1 Check whether all
drivetrain
components are
free of damage.
2 Contact your specialist dealer if components
are damaged.
3 Place the
ebike
on stand.
4 Turn the pedal crank clockwise.
5 Switch through all speeds.
6 Check that
ebike
can switch through all
speeds without making unusual noises.
7 Adjust the
derailleurs
if gears can not be
changed correctly.
7.5.10.1 Electric
shifting
1 Check the cable connections for damage and
corrosion and ensure they are firmly in
position.

If cable connections are loose, damaged or
corroded, contact your specialist dealer.
7.5.10.2 Mechanical
shifting
1 Change gear a number of times. Check
whether the cables get stuck or they make
scraping noises.
2 Check the physical condition of the
cables for visible damage and check to see if
wire strands are broken.
 Have defective cables replaced. Contact
specialist dealer.
7.5.10.3 Checking the derailleur gears
1 Check that there is clearance between the
chain tensioner
/cage
and spokes.

If there is no clearance or the chain scrapes
against the spokes or
tires
, contact your
specialist dealer.
2 Check that there is clearance between the
chain or rear derailleur and spokes.

If there is no clearance or the chain scrapes
against the spokes, contact your specialist
dealer.
10-15 mm
10-15 mm