
When
assemblying your new Charger electric bike, plan to install tire
liners and thorn-resistant tubes. Some folks wait until they
get their first flat, squeeze in some Slime, pump up the air
pressure, and go for a ride. If the Slime doesn't seal the
puncture, then they use this procedure to add tire liners and TR
tubes. [Editor's note: I'm one of those people.]
A bike stand
to hold the bike up makes this procecure easier.

Important
Note:
Throughout
this procedure, the right cover panel is shown installed on the bike.
After several attempts, we've concluded that removing the panel makes
the most sense. Many folks have problems with the pinion gear
when removing and installing the two chains. Removing the side panels
effectively eliminates those problems.
If
the motor's power chain gets too loose, it will fall off the pinion gear.
If it goes to the outside, it tends to jam up. If it falls to
the inside, it will hang on the pinion gear's shaft.

In addition to
the pedal chain, there's a motor chain, brake cable, and (not visible
in this photo) a gear-shifting cable which must be disconnected
before removing the rear wheel.
(Click on
photo for enlarged view.)

To loosen the
motor drive chain, unscrew the tension-adjusting bolt until it's
nearly out. This allows you to reach behind the gray plastic
side panel to pull the chain out and off the large sprocket at the
rear hub. (Removing the side panel takes extra time but will
make this easier. After removing the screws that hold the panel
in place, rotate the pedal crank to the 5 o'clock position so you can
work the panel off the bike.) Leave the drive chain on the
motor sprocket (or you'll have to remove the gray side panel to
replace it).
(Click on
photo for enlarged view.)

Once free of
the large sprocket at the rear hub, the motor drive chain can be
pulled to the rear and over the side panel to rest out of the
way. Now, you can loosen the axle nuts with a 15mm wrench;
unscrew them until they're nearly off.
(Click on
photo for enlarged view.)

The brake
cable can be easily disconnected by removing the cable retaining nut
from the brake lever arm; a small spring-clip holds it in place.
The brake housing is held to the frame with a 10mm screw (shown with
hex/Phillips head) and a Nylock nut; remove them.
If you ever
adjust the rear brake cable lock nut, make sure the grooved washer
seats properly on the cable, or else it will deform and require
replacement (or filing for it to fit back on). (Click on
photo for enlarged view.)

The brake
cable housing ends with a machined piece that loosely slides into a
receiver in the brake housing. After slipping it out, all
connections on the left side should be free.
(Click on
photo for enlarged view.)
Don't
slacken the cable retaining nut (faces out) for the Nexus 7-speed
hub when removing the rear wheel. You need only push the
spring-loaded "key-way cassette" (that holds the cable
retaining nut) in a counter-clockwise direction. Then, with
your other hand, twist the end of the cable in the same direction
(counter-clockwise) to allow the nut to slide out of the key-way.
(Click on
photo for enlarged view.)

Unscrew the
nut(s) on the "banjo" tensioning bolt until it's nearly
off. Pull it away from the frame so it hangs freely.
[Editor's note: these photos don't show the "banjo"
bolt. Click here to see them.]
Now, you can push the axle forward to create slack in the pedal
chain. Reach inside the gray plastic panel and lift the chain
off the big pedal sprocket; let it hand inside the sprocket on the
frame's bottom bracket.
(Click on
photo for enlarged view.)


Pull the pedal
chain back and out over the frame to hang out of the way. Now
there's nothing holding the wheel to the frame, so slide it back and off.
(Click on
photo for enlarged view.)

Re-assembly
starts with replacing the wheel onto the frame.
(Click on
photo for enlarged view.)

Put the chains
back where they came from. Pull the axle back until the
"banjo" tensioner bolt assembly fits onto the rear end of
the frame. (Click on photo for enlarged view.)
Tension for
both pedal and motor chains is important. The motor chain,
which is adjusted after the pedal chain, is easily adjusted by
turning the Allen head motor tensioning screw in and out. The
pedal chain is adjusted the way BMX bikes are done: loosen both
axle nuts, move the rear wheel forward or rearward, and retighten the
axle nuts. A broom handle-sized dowel works to pry between the
frame and the tire. On bikes with fenders, this doesn't work
unless you turn the bike upside-down (not practical). For this
reason, Charger bikes also have a "banjo" bolt chain
adjuster that goes on the right axle before the two lock washers and
nut. The "banjo" allows chain adjustment by turning a
nut (after the axle nuts and brake housing-to-frame nut are
loosened). With the pedal chain nearly the right tension,
lock down the left side with the wheel cocked to the left
slightly. Then, tighten the banjo nut on the right to both
straighten the wheel and tighten the chain tension.
Once the pedal
chain is set, this is a rare adjustment. However, you should
check the motor chain tension regularly. It should not be too tight
or too loose (about 1/2 inch of movement at the middle), and ride no
closer than a sixteenth to eighth of an inch from the pedal chain. We
emphasize chain tension and alignment because broken chains are a
pain to replace (usually fail if they are too tight or catch on the
adjacent chain), and loose chains that come off can get damaged and
possibly damage the torque sensor. (PLEASE NOTE: If the
Allen head screws holding the torque sensor in place become loose,
this could cause the pedal chain to come in closer contact with the
motor chain, causing problems. There must be 2 washers between
these Allen head screws and the torque sensor plate, and we also
recommend "LocTite".)