Merida City Bikes, Operating Instructions Manual

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51
e
f
g
Multi-speed hubs (internal gear hubs)
Functioning and operation
The advantages of multi-speed hubs (d+e) are their
enclosed design. Unlike derailleur gears the gear drive
is within the hub body, only the primary ratio from the
chainwheel to the sprocket being outside. What is more,
all the gears can be shifted through with one gear shifter.
Provided that it is serviced regularly, the drive chain
has a comparatively longer service life. And this applies
even more if it is protected from the influences of the
weather by a sealed chain box.
With multi-speed hubs normally the power transmission
and the gear ratio adjustment is guaranteed via one or
several planetary gears, depending on the number of
gears. To shift gears the pedal force should be reduced
shortly.
In contrast to derailleur gears, multi-speed hubs cannot
only be combined with manually actuated brakes (rim,
drum, roller or disc brakes), but also with back-pedal
brakes
(f) (roller or drum brakes) that are actuated by a
reverse rotation of the pedals. The most effective brak-
ing is achieved with the pedals in the horizontal position.
In the case of multi-speed hubs and gearbox shift sys-
tems “1” stands for the first, lowest gear. The gears are
shifted through one after the other, if possible without
turning the pedals, at least, however, at reduced ped-
al pressure. The highest number stands for the highest
gear.
NuVinci N360 gear hubs (g)
are designed to allow step-
less shifting by means of a twist grip within their range of
gear ratio. With the NuVinci hub the force transmission
is ensured by balls instead of toothed wheels. Make it a
rule to shift only while pedaling at reduced force.
With
NuVinci
the actual gear ratio is indicated by the
cyclist on the display. If the cyclist climbs uphill, the gear
ratio is low, on level ground the gear ratio is high.
The
H-Sync
gear system integrates the
NuVinci
Harmony
® gear hubs into the Intuvia system of its
Bosch drive. With H-Sync you can predefine your pre-
ferred cadence (between 30 and 80 turns per minute).
The drive readjusts automatically – both uphill as well
as downhill. This allows you to always maintain your
preset cadence.
For more information see the instructions of the compo-
nent manufacturers on this MERIDA CD-ROM.