True Hub Motor versus Motor-in-a-Hub All our motors are true hub motors. That means there are no gears, no
pulleys, sprockets, chains, or any other transfer of power to wheel but
electromagnetic force. There is another kind of motor that looks like a hub
motor, but is not. It's actually a motor inside a hub, mounted to the stationary
axle, and driving a ring gear on the inside of the hub. We prefer true hub
motors because of their reliability and higher top speeds. They are also quieter
and our brushless motors have no internal parts to wear out.
Sensorless versus Sensored In most brushless motors, there are Hall effect sensors - one per motor
winding - that tell the controller where the "hot" winding is in
relation to the center of the magnet it is trying to reach. Just before the
center is reached (maximum pull), the controller switches the current to the
next (lagging) winding until it almost reaches the center of the magnet. There
are a lot of magnets, so each full revolution of the motor requires firing each
winding many, many times. Hall-effect sensor feedback is analog and continuous
whether motor is turning or not, so when starting, the controller can choose the
correct winding to power based on the sensor feedback. A sensorless motor
works the same way, but the controller is far more sophisticated. Some means of
determining the powered winding's position relative to the next magnet is still
required. The sensorless controller determines this by looking at the amount of
energy being "reflected" by the windings themselves. When the
"reflection" begins to weaken, the controller switches power next
winding. This works great when the wheel is turning, but what if it's stopped
(stalled)? Since there are no sensors to provide position data, the controller
has to make a guess as to where to apply power to start the wheel turning. You
will hear a clicking sound as the controller switches from one winding to
another trying to get the motor to start. Any motion at all enables the feedback
process to start working so efficient operation can begin. We think it's a small
penalty relative to the gain of not having any electronics in the motor. That
positions our systems for long range travel as batteries become available to
provide the power. A summer day in West Texas can reach over 110 degrees.
Sensors are vulnerable to heat, so by removing them from the motor we can run a
lot farther and hotter without damage.
Front versus Rear Wheel Drive
Each has advantages and disadvantages. The rider is
more aware of what the front wheel is doing. If it starts to spin, the
rider has an additional plane of control. That is, you can turn the front
wheel to maintain balance and correct for the spinout. The front wheel has
less weight on it, though, so will spin more easily. Steep hills on
non-paved surfaces can be a problem for this reason. Rear wheel drive has
the advantage of better traction, but if you apply too much throttle on a
turn and the wheel starts to spin, you will probably hit the ground as the
bike goes out from under you (you can't turn the rear wheel as you can a front
tocorrect for the slip). Rear drive puts the entire weight of the
system on the rear of the bike rather than battery weight in back, motor
weight in front. Rear dropouts on bikes are heavier than front, and can
take more torque. If you use a rear drive, you can still have front
suspension. Note that Phoenix is the only system with special frame
requirements. RoadRunner and Sparrow do not produce nearly as much torque
and can go on just about any mountain bike or cruiser frame. All said, when you ride
the bike normally, you can't tell the difference.
Brushed versus Brushless
Sparrow is a brushed motor. That means electrical energy is transferred to the
motor via metal parts called brushes that contact a rotating part of the motor
called a commutator. Because there is physical contact between stationary and
moving parts, wear will occur, and over time (appx 3000 miles), the brushes will
have to be replaced. Replacement is easy, but getting the motor back together is
not. Our service center can do the job for you if you cannot. Brushed motors
require a less complex controller than brushless motors, so the system is less
expensive. Brushed motors are ideal for "Sunday" riders, who will
typically ride for years without motor maintenance. RoadRunner and Phoenix are
brushless motors. Brushless motors have no wear parts inside the motor. The end
result is a motor with no theoretical life limit. Brushless motors have more
sophisticated controllers than brushed motors, and there are many more
connections from the motor to the controller. The motor has three windings.
Power is applied to individual windings depending on where the motor is in its
revolution. The feedback that gives the controller position information is
provided by a separate multi-conductor wire that carries signals from
hall-effect sensors inside the motor. As the motor passes the maximum
electromagnetic pull from one winding, the controller moves the power to the
next winding to keep the motor turning.
Disc and Rim Brakes
We have been testing disc brakes for about a year and beginning June 2009, we
began offering all Phoenix motors with disc brake option. We are very pleased
with the product. Remember, tho, that Phoenix motors put a lot of torque on the spokes in forward direction. Disc
brakes put a lot of torque on the spokes in opposite direction. We have
used 12ga spokes for years because the standard 14ga require more maintenance than most people care
to perform. It is best to check the spokes after about 25 miles of riding
when the wheel is new, then tapering down to every few hundred miles as the
spokes stretch and reach their maximum strength. Rim brakes put no stress on the spokes, and modern brake
shoe materials are not affected by moisture, so rim brakes remain a
good choice.
Lacing to Rims
We have our heavy-duty 12 gauge spokes manufactured to
the correct length for our rims. Different rims require different length
spokes because some are double walled (like ours), some have raised
ridges, and others don't. If our spokes fit your rim, there is no reason
not to use your existing rim. If they don't, you will need to find a bike
shop that can cut spokes to the correct length for your rim. While many
shops have the equipment to cut standard 14 gauge spokes, we know of none
that can cut 12 gauge. 14 will work with our motors, but they need to be
adjusted much more frequently.
700c Rims
We are pretty picky about performance. That is, if we
don't think we'd be happy with it for personal use, we don't think you
would. All Phoenix motors handle 700c rims with ease, but it's just beyond
the limit of RoadRunner and Sparrow for our taste. We will lace them to a 700c rim if you insist, but we want you to
know they don't have a lot of guts. OTOH, people sell much lower power systems
on 700c rims, so maybe we're too picky.
Rough Pavement or Dirt Paths
Because of the increased weight of the system, every
part of a bike is under more stress. A 180 lb person with our largest
system would put 250 lbs on the bike. That's within the limits of just
about any bike made. A 300 lb person would put 370 lbs on the bike, over
the limit of just about any bike made, and probably too much for off-road.
Whether you ride on or off road, check your spokes frequently. Regardless
of whether it is electric or pedal, off-road use is typically much harder
on any vehicle.
Wires from motor to controller Brushed
motors (Sparrow) have two conductors, positive and negative. Brushless
motors (Phoenix, RoadRunner) have three conductors for power going to the
motor, and a 5-pin cable for Hall effect sensors.
Phone Hours
Mon-Fri
9AM - 5 PM
Central Time
Local: 325-227-6903
Toll Free: 866-807-4337
Email: sales@electricrider.com Service Dept: 325-227-6903 Go green with a company who will back
you up! Buy with confidence, we'll be here when you need us!
ElectricRider
1301 Pulliam Street
San Angelo, TX 76903
In our 10th year of service to the electric bike and LEV community
