Die Rohloff Nabenschaltung

Rohloff-14speed-hub

Hint: arguments in italics refer only to the use
of the Rohloff-hub in "Magic Scooter 2" !

Advantages in practice

Unnecessary coordination between front and rear derailleur. It´s only
one gear grip ( which in addition works very exactly caused by the
use of 2 ropes and gear-stepping directly in the hub )

Problems with changing gears are history ( e.g. contact of the front
derailleur with the crank, rattling by a wrong adjusted derailleur, etc. )

The chain doesn´t jump down so easily ( for lack of chain activities )

The progress of changing gears is faster ( especially when also the
chainring had to be changed otherwise )

Changing gears is also possible at a standstill and without pedaling

The upper chain runs near the middle -> no leg contact , i.e. clean legs !

Advantages in efficiency

The upper chain runs without lateral move of its line, contrary to normal
gear systems the lower chain has always the same chain line
-> by that the chain line can get optimated, i.e. the lateral
move can get minimated ( 15mm )

Better chain efficiency, because a 15th and a 20th sprocket
instead of two 14th (biggest gear) can get mounted

Advantages in maintenance

Very small expenditure on maintenance

No adjustments necessary in the hard reachable bottom bracket area

Less sprocket-/chain-wear because of no chain side moves

Visual "advantage"

Very clean and tidy appearance of the drive

Disadvantages in practice	Possible compensation
The gear steps are a bit too big, especially in the upper speed area. 7 to max. 9 % would be perfect instead of more than 13 %.	This is the biggest disadvantage, but almost not to change without catching other disadvantages at the same time. One possible solution for that would be an additional chain derailleur between a 15 and 16 sprocket to halve the steps. For translation into practice the gear change would have to occur electrically then with step engines and would destroy several advantages of the Rohloff-hub ( maintenance, speed of gear-change, etc. ). Suggestions to solve are very welcome.
The sounds of the speedhub are intensified by the big resonance space, which can affect problems in radio traffic	Put some cotton-wool in the left ear
Disadvantages in efficiency & weight
Less hub efficiency (in some gears)	When using the hub you can use bigger sprockets with corresponding higher efficiency. Besides the lateral move of the chain line is lower ( depending on the chosen gear, especially in the big gears ) and therefore the efficiency higher again.
Additional weight of about 300 - 400 g, mostly as moved mass ( but near the axle )	Further "mass attacks" than otherwise on other parts especially at moved masses like the rear wheel , the front rim and tyres ( surely no real compensation, but with fully faired bikes the courses normally are very flat )

Result : This time there´s no alternative to the Rohloff-hub in spite of the big gear steps !!

Something about efficiency

The light streak shows the efficiency field of the Rohloff-hub with the gear 46-16,
the hatched streak the efficiency field of a 24speed-XT-drive (46-11 till 26-28).

Conditions for measurements:
drive frequency                         60min-1
braking power (constant)        314W
a pulsating power of 160 W is simulated by that
drive torque                50Nm
several repetitions
measurements with clean components as well as with those driven about 1000km
( here with the XT-drive 1% lower on an average )
The efficiency field also includes the tolerance of the measurement accuracy of +/-0,5%