1. General remarks How it works Lubrication
Chain adjustment Anti-rotation Setting gear
range with: 3 speeds 5 through 8 speeds 9
or more speeds Hybrid gearingInformation
on specific brands and modelsRohloff
SRAM/Sachs Shimano
Sturmey-Archer14-speed All, but alsosee
links below 3-speed 3-speed4-speed 4 and
5-speed7-speed 7-speed9-speed 8-speed
8-speed12-speed 11-speed hybridGeneral
remarks
fixed gear bikes

2. Since the first decade of the 20th century, internal-gear hubs, usually
3-speeds, have offered a practical, reliable gear-shifting option to the
cyclist With the popularity of derailer gears taking off in the early 1970's
bike boom, internal-gear hubs went out of style in most US markets This
is unfortunate, because many casual or utilitarian cyclists are best served
by this type of gearing tn pas cherInternal-gear hubs are more reliable
than derailer systems, and require much less maintenance The step-up
ratios of their top gears make oversize chainrings unnecessary on
small-wheel folding bicycles Unlike derailers, internal hubs can shift at a
stop, very nice in stop-and-go urban traffic Internal-gear hubs tend to be
heavier than derailer systems, and are slightly less efficient in some
gears The direct-drive middle gear can be more efficient than in a
derailer system, as there is no drag from derailer pulleys Most
internal-gear hubs cannot have a quick-release axle If you are interested
in old bikes, or the history of this sort of gearing, refer to my page on
English Three Speeds How an internal-gear hub worksInternal-gear hubs
work on the principle of "planetary gearing

3. "The basic 3-speed hubs have a single "sun" gear solidly attached to the
middle of the axle 3 or 4 identical "planet" gears mesh with and revolve
around the "sun" gear The "planet" gears are surrounded by (and mesh
with) a"gear ring" with its teeth on the inside (an inside-out gear) As the
planet gears, attached to a part called a "planet cage", revolve, the gear
ring revolves 4 times for every 3 times the planet cage goes around
(Some models have different ratios )Low Gear has the sprocket driving
the gear ring, while the planet cage drives the hub Thus, the wheel turns
3 times for every 4 revolutions of the sprocket, lowering the gear by 25%
Middle Gear has the sprocket still driving the gear ring, but has the gear

4. ring drive the hub Thus, the drive is direct Although the internal gears
are always rotating when the sprocket is in motion, they don't have any
effect on the drive in middle gear High Gear shifts the sprocket's drive to
the planet cage, while the gear ring continues to drive the hub shell

5. Thus, the hub turns around 4 times for every 3 sprocket revolutions,
giving a 33% gear increase There is a more detailed explanation of this
on the Sturmey-Archer Web site, from which I lifted the image above
Hubs with more than three speeds use two or three planetary stages,
and/or compound (stepped) planet gears with two or more sets of teeth
side by side -- see John Allen's article describing these in more detail tn
pas cherIn the late 1990's, internal gears underwent something of a
renaissance, with the development of wide-range 7-speed hubs
Progress has continued since Four different brands are currently
available, with as many as 14 speeds Three-speeds and five-speeds are
still currently in production, and they offer an economical, practical
alternative [Next three sections are by John Allen ]LubricationOlder
internal-gear hubs have an oil fitting on the shell Oil lubrication generates
less drag than grease and washes wear particles, dirt and water out of
the mechanism

6. Use machine oil, not a spray lube or other thin oil Unless a hub has
sealed bearings, also use grease, to form a seal at the bearings and help
keep the oil in The Rohloff Speedhub and the Shimano 11-speed are
oil-lubricated Other current internal-gear hubs are supplied
grease-lubricated As sold, they require periodic cleaning and
replenishment of a special grease that does not make the pawls stick
Shimano sells a relubrication kit for grease-lubricated hubs Still, many
hubs are inadequately lubricated as sold, and frequent failures of
grease-lubricated hubs due to water contamination have been reported in
wet climates --see photos here Better lubrication sidesteps this problem
It is best to add oil to the lubricant regimen when rebuilding a hub, so it
gets a clean start and you also can regrease it This is desirable even
with a new hub

7. Follow the example shown in the photos from Aaron's Bike Repair (near
the bottom of the page, after you get past the horror-show photos of
rusted parts at the top) Use plenty of waterproof marine grease (as used
in boat-trailer wheel bearings) for the bearing assemblies -- this keeps
water out and oil in; use lightweight white lithium grease for the gears,
especially with modern wide-mouth hubs that hold oil poorly; Phil Wood
Tenacious Oil on the pawls and in the shell to slop around and get to
where the grease didn't reach An internal-gear hub with a hollow axle
may be re-oiled by removing the pushrod or indicator spindle and
squirting oil into the end of the axle The SRAM i-Motion 9-speed, disk
brake model, can be oiled through a disk brake rotor hole Plug all the
holes with machine screws between oilings On a hub which doesn't allow
one of these tricks, you could install a Sturmey-Archer oil cap Tools: #3
(or 5 5 mm) drill and a 1/4 inch 28 TPI tap A simpler but less convenient
approach is to unscrew the left bearing cone and squirt oil in past the left
end of the axle Oil can accumulate on the hub shell, and can become a
bit messy, but, big deal

9. On the other hand, if used to excess, oil can run down the spokes onto
the rim, soften the brake shoe rubber and make a rim brake squeal and
grab This is hazardous in a front wheel, but the internal-gear hub is in
the rear wheel Cleaning the oil and brake-shoe rubber deposits off the
rim restores brake function Also, it is best to store your bicycle in an
unheated (but dry) area When you take it out from a heated area in cool,
moist -- or wet -- weather, the air inside the hub contracts, pulling in
moisture If you must store your bike in a heated area, be especially
careful about keeping the hub oiled Old Sturmey-Archer coaster-brake
3-speeds have an oil fitting, but other hubs with a coaster brake require a
special high-temperature grease for the brake shoes Some hubs use a
different grease for the rest of the mechanism, so the pawls don't stick A
coaster brake in an internal-gear hub is, all in all, a poor idea because of
the wear particles it generates, and because you can't use oil lubrication
Oil lubrication may cause problems with a drum brake, by seeping out
past the bearing and contaminating the brake shoes

10. Phil Wood Tenacious Oil stays in place better than most other oils
Unlike with derailleur bicycle, if you must store or transport the bike
horizontally, lay it on its right side This will prevent oil from leaking into
the drum Place something under the rear wheel to catch the drip,
especially if you have just oiled the hub Shimano roller brakes are
sometimes referred to as drum brakes, but are actually similar to coaster
brakes They use steel brake shoes inside a steel drum and require
periodic lubrication with high temperature grease Adjusting the
chainInternal-gear hubs typically use a single sprocket and single
chainwheel The chain is held in place by moving the hub's axle forward
or backward in the dropout slots until the chain is just barely slack
Details of how to do this are in another article on this site A bicycle with
vertical dropouts must have an eccentric bottom bracket, or a chain
tensioner must be installed

11. As the chain wears, it lengthens, and it is more likely to fall off It must be
readjusted periodically Technique for chain adjustment is described in
the article on fixed-gear bicycles Anti-rotationThe axle is part of the gear
train of an internal-gear hub You can check this out for yourself If you
hold the hub shell or rim when the hub is not installed on the bicycle and
turn the sprocket, the axle also turns -- backwards if the hub's drive ratio
is lower than 1:1, forwards if higher Special anti-rotation washers keep
the axle from turning when the wheel is installed on the bicycle These
washers engage flat surfaces on the axle, and have tabs that fit into the
dropout slots Different washers fit different models of hubs and dropout
slot widths Many newer hubs attach the shifter cable to a pulley that
rotates around the hub's axle, between the right dropout and the sprocket

13. Depending on whether a bicycle has horizontal, vertical or reversed
(track) dropouts, different washers are needed so the shift cable can
approach from the front of the bicycle Follow the instructions for each
hub Anti-rotation washers for Shimano Nexus internal-gear hubsA hub
brake of any kind also must resist rotation Brakes on internal-gear hubs
use a reaction arm for this purpose, separate from the anti-rotation
washer(s) for the gearing You must install them too The Rohloff hub has
such a wide gear fixed gear bikes range that some models use a reaction
arm instead of anti-rotation washers On a bicycle with rear suspension,
the suspension's pivot is usually ahead of the rear hub Because it tries to
rotate the hub's axle, an internal-gear hub lifts the rear end of the bicycle,
reducing "pogo sticking" in gears below 1:1; the opposite in gears above
1:1 Pogo-sticking reduces pedaling efficiency, to a degree which depends
on the design of the suspension click here

14. fixed gear bikes