El Cheapo ControllerEl Cheapo Front wheelEl Cheapo 2
OwnerEllis Madsen
Owner's Other EVsLowTrike
Brico v2.0
LocationLouisville, Kentucky US map
Email email image
Vehicle1958 NSU Female Bicycle
This is a conversion of a one-speed female or step-
through bicycle using a donor rear wheel as the front
electric powered wheel. It is a hybrid: it can use electric
power, pedal power or both simultaneously. It was made
using only hand tools including hacksaw, wrenches, bolts,
and power drill.
Motor Has 99:11 gear down to a 9 tooth bicycle sprocket Permanent Magnet DC
Motor RPM: 2750; sprocket RPM: 382. Dimension: 4.25”
diameter x 2.75” long 4..5” long including transmission and
output shaft. Three mounting holes.
DrivetrainThere are two separate drive trains. The first is the pedal
system of the main bicycle, which is not at all interfered with
by the other, electric drive train. The electric drive train
operates only on the front wheel by a bicycle chain.
Controller hand made with three forward values: 12V, 18V, 24V
This is a hand-made switch with three values. The contactors
are made of bicycle chain links. It is the same controller I
used on the Low Trike. See the attached diagram.
Batteries20 10000 mA, 1.20 Volt, Nickel-Metal Hydride
I used 20 D-cells in 4 modules of 5 batteries. I built a
battery holder using bungy cords to hold them in. Each
module is a unit that has connectors to respectively the
charger or the controller. Since the controller uses; the
first two modules more often that than the third, which
itself is used more than the fourth (as the vehicle
accelerates), the order of modules must be rotated
periodically to achieve a similar discharge of all the
modules.


System Voltage24 Volts
Charger hand made from charging modules
I built a charger that plugs into the 4 connectors form the
battery modules. There are 2 connectors in parallel form
2 modules. These are very low amperage maybe 0.1A so
it takes a LONG time to charge the battery modules. The
charger modules automatically measure the charge and
voltage of the batteries they are charging and the LED
glows when fully charged. 7.2V max.
Heaternone
DC/DC Converter none
Instrumentationhand held multimeter, if I don’t forget to bring it along.
Top Speed15 MPH (24 KPH)
fast enough for me, and fast enough to brake.
Accelerationnot great, but better when pedaling.
Range12 Miles (19 Kilometers)
estimated
Watt Hours/MileAll calculated. 10A X 24V = 240 W. I figure 0.9 hour’s range
for ca. 13 Miles, with a generous fudge factor.
Seating Capacity1
Curb Weight35 Pounds (15 Kilograms)
estimated
TiresRear is 27 inch. I used a 26” front wheel from the donor.
Conversion Timeabout one month of part-time garage work; maybe 50 hours
Conversion CostMotor: $90. Batteries: ~$160. Chain: $5. Turnbuckles: $8.
You could use 4 lead acid batteries of 6V each with the same
controllers. I didn't have to pay for the bicycles
Additional FeaturesThis was designed to be as cheap as I could make it. I had the basic bicycle—something
of a collector’s item—from my days in Germany and the donor rear wheel for the front
electric wheel was from a freebee I picked up on Junk Day. The special features include
the hand-made controller—you could also use a more traditional, and more continuous,
commercially available controller and handle potentiometer. The other feature is the
ability to use the turnbuckles to tension the chain when you are fitting it around the
front wheel gear and the motor drive gear. This would, furthermore, allow you to
change the gear ratios slightly between trips, but I have never don that.
I tried to make the cheapest electric conversion for a bicycle that I could. In fact you
could come in at only a bit more if you bought a front wheel hub motor conversion--
with batteries--and with less work.

code by jerry