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Building
Building an
an eBike
eBike
POWER your (Puff, P
Riding a pushbike is great exercise – until you come to hills!
Unless your name is Evans or Armstrong et al, unless you’re one of
the lycra brigade who keep super fit by pedaling everywhere and
anywhere, even if your pushie has 150 gears and weighs about a
hundred grams, you often wish that you could have just that little
bit of assistance when the going gets tough!
M
y first pushbike came courtesy
of Santa when I started high
school. And I’ve had one (or
more) ever since. While I enjoy riding
my pushie and acknowledge that it’s
one of the best forms of exercise, I’m the
first to acknowledge that I’m not quite
as fit as I once thought I was.
In fact, riding for any distance (with
the emphasis on any!) certainly takes
it out of me. So often I’ve wished for
a motor of some sort to ease all those
strained muscles, especially walking
the bike up hills that have beaten me!
Building a bike for the teacher
Some months ago our esteemed edi14 Silicon Chip
tor and I visited a school which regular
readers would be familiar with because
we’ve featured it before in SILICON CHIP:
Mater Maria Catholic College in Warriewood, near our editorial office on
Sydney’s northern beaches.
We were there at the invitation of
Dave Kennedy, the school’s electronics/technology teacher, to review the
major projects being built by his senior students for their Higher School
Certificate.
Most of those projects came from
the pages of SILICON CHIP; many were
By Ross Tester
variations on those projects (and those
variations were where some of the
builders struck snags!).
Having spent the best part of a day
talking to the students and solving (we
trust!) many of their problems, we were
intrigued to spot what was going on
(through the glass) in the classroom
next door. Here his younger (year
nine) students were building an electric
pushbike.
In fact, Dave Kennedy had purchased
a brand new pushie (nice bike, Dave!)
and an electric motor conversion kit
specifically for the students to gain
some “hands on” experience.
The bonus was that when it was finsiliconchip.com.au
Puff) Pedal Pushie!
ished, Dave could ride to school – about of (power assisted) exercise.
it on public roads?
5km or so across mainly flat terrain but
So we approached the distributors of
We’re not lawyers (even of the bush
with a nasty hill at each end. It was for the kit which Dave Kennedy had pur- variety) and it took a bit of digging to
these hills which Dave hoped a motor chased – Rev-Bikes in Victoria (www. get the answer.
would keep him from becoming too hot
rev-bikes.com) [see end of article] and
This appears to us to be yes. . . but!
and bothered when he reached school this article is the outcome.
The rules appear similar (if not ideneach morning.
tical) in all states but we will use NSW
The completed bike looked pretty Legal or not legal?
regulations as our yardstick.
impressive – from the fire-engine red
This was our first question. Is it legal
Quite simply, according to the NSW
frame through to the in-wheel motor to put a motor on a pushbike and use RTA website (www.rta.nsw.gov.au/regand controller, along with all the
istration/unregisteredvehicles/
controls and wiring necessary.
scootersminibikes.html) you can
One of the students, Alex, even
put a motor on a pushbike with
took a few photos of it for us.
the aim of assisting pedaling, as
But this started us thinking –
long as the output power of that
why not a project in SILICON CHIP
motor does not exceed 200W.
showing how to build an electric
There are two points to note
bike (or, to be more accurate,
here: first is the motor is not
how to convert an existing bike
intended to replace pedaling as
to electric-assist).
the means of propulsion – it is
By the time we got back to the
there to assist.
office, the editor and I were conIndeed in most European
vinced that many readers would
countries the motor doesn’t work
like to know how they could
at all unless the pedals are being
bring that old pushie back to life
pushed (thankfully, they haven’t
The Year 9 class from Mater Maria with the newly(you know, the one with flat tyres converted “Diamondback” mountain bike. At left is
brought that one in here . . . yet!)
hanging on the garage wall!) and Malcolm Faed, whom readers will recall converted
The second point is that
perhaps get some benefit by way his ute to battery/electric power (June 2009 issue).
limitation of 200W. To be frank,
siliconchip.com.au
November 2011 15
Lay out all components on a table or clean floor to check that you
have everything. Here the tube/tyre is already fitted and there are
some differences between this kit (the Mater Maria kit) and the one
we used. At right is a shot inside the “Magic Pie” motor, which also
shows the integrated controller.
that’s not much at all, especially if it is
pushing around a 100kg rider. Again, it
will only assist you, not really propel
you.
There are lobby groups currently
trying to have that raised to at least the
European standard of 250W – again, not
much, but better than 200!
If the motor is rated at higher than
200W, then the pushbike becomes a
motorbike and must be registered as
such – except that it is almost impossible to do so because the “motorbike”
does not have all of the equipment
demanded by Australian Design Rules,
such as turn indicators, brake lights and
so on. Catch 22 all over again!
Just as importantly, the rider must be
licensed to ride a motor bike – again,
impossible if they are under age.
How are the motors tested?
As far as we are able to ascertain,
authorities (Police, traffic, etc) cannot
test motorised pushbikes in any state,
simply because they do not have any
equipment to do so.
In most cases, the motors (especially
in-wheel types) do not have any power
or other identification on them so the
boys in blue cannot even look up a
reference to say “You’re nabbed!”
Anecdotal evidence suggests police
tend to use their own judgement – if
you are whizzing along a road at 50km
per hour, not pedaling, they might
take a slightly more jaundiced view
of you than where you are riding at a
slower speed and at least appear to be
pedaling!
So which motor to go for?
We’ll get on to motor specifics in a
moment but the source we obtained our
16 Silicon Chip
motor from has several different models
available – not only various sizes (to
suit most bikes available in Australia)
but also in power levels.
First is a 200W motor so it is absolutely legal, regardless. It’s also the
cheaper alternative.
Second is a much more powerful
motor – rated at 1000W – which can be
“governed” down in output power via
the use of a computer program.
As perverse as the high power motor
option sounds, that’s the way we went
for the SILICON CHIP pushie power conversion. Why?
Most importantly, the higher-power
motor programmed down would be
operating way below its maximum
rating, therefore its longevity is much
more assured. A 200W motor would
be operating at maximum most of the
time, therefore wear and tear would
be expected to be much more a factor.
Secondly (and yes, this does sound
like a cop-out!) we knew that we would
have the opportunity to use the bike on
some mountain bike tracks on private
property where that extra power would
come in real handy. By taking along a
notebook computer, it would only take
a few moments to re-program the motor
to full power and back down again.
Having said all that, SILICON CHIP
does not endorse, in any way, the fitting
of an over-powered (ie, >200W) motor
to a pushbike for on-road use.
Front or rear . . . or both?
There is one other consideration, that
is whether to fit the motor to the rear,
to the front or even (as we have seen
in pictures only), both front and rear!
Assuming you’re only going to fit one
motor, there are arguments for both fit-
ting to the rear and fitting to the front.
The rear, which suits a 135mm fork
width, should mean best traction, because it is driving the wheel which is
normally driven by the pedals/chain.
However, this puts a lot more weight
at the rear of the bike, possibly resulting in less control (eg, steering can be
a little “vague”, etc).
A front motor, (100mm fork width)
should be easier to fit (no problem with
gears etc) and also the weight is more
evenly distributed, which theoretically
at least, gives the best control.
Fairly obviously, fitting a motor to
both front and rear would result in a
lot of power – but it would also be just
as obvious that you were running significantly more than 200W and could
automatically draw the attention of the
authorities that you don’t really want.
It would also be a quite expensive
exercise, not to mention the difficulties
of controlling those two motors as one.
One further point: regardless of the
motor to be fitted, they aren’t suitable
for carbon-fibre or other lightweight
bikes. You need a strong, steel fork to
take the strain.
Which battery?
There’s a range of batteries available
to not only suit the motor you choose
but also give extra performance.
The voltage of the motor you install
determines the amount of power or
torque you will get; the higher the voltage, the faster the take-off.
Our kit came with a 48V motor so we
obviously needed 48V battery. The one
supplied was a Li-ion type but you’ll
find other types to choose from on the
Rev-Bikes website.
For example, they also have LiFePO4
siliconchip.com.au
The wheel
as supplied
with a 1000W
Magic Pie 48V in-wheel
electric motor. This is one
of several models available.
types 24V (16Ah), 36V (12 or 16Ah)
or 48V (10Ah). LiFePO4 are more expensive but charge in half the time as
Li-ion and last twice as long.
All come with a mains charger (an
optional solar charger is also available).
A battery management system monitors each cell within the battery for the
longest possible life.
The range with a fully charged battery depends on the type and capacity
but as a minimum, you would expect
30km or so per charge without significant regenerative braking.
The kit
Meanwhile, back at the ranch . . . we
approached Rev-Bikes and explained
who we were and what we proposed.
They were most helpful in our discussions and agreed that an article in SILICON CHIP would be a great idea.
So within a few days, a large package arrived from Rev-Bikes and we got
ready to attack a perfectly good Dunlop
26” mountain bike.
Well, attack is probably a bit harsh
as you don’t have to make any real
changes to the bike, except for fitting
the motorised wheel, the battery and
all the controls.
First of all . . .
Lay all the components out on a table
or garage floor to ensure that everything
is supplied. It also makes life easier
later on if you identify the various components now. The photo actually shows
the Mater Maria kit which is slightly
different to that which we obtained.
Charge the battery
While going through the various assembly steps, it’s a good idea to plug
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The spokes are usually loose to prevent warping in transit.
A $6 spoke key soon had them nice and tight.
the battery into its mains charger so
that when you want to use it, it’s fully
charged.
The battery charger plugs into a
socket on the battery pack which is
revealed when you raise the handle 90°.
The battery does not have to be plugged
into the motor or controls to charge.
Fit the tube/tyre
The wheel rim is “double walled” to
ensure that it can handle the enormous
torque generated by the electric motor.
Apart from that difference, fitting the
tube and tyre is exactly the same as on
a conventional wheel, with the possible
exception of the valve stem.
Rev-Bike suggest buying a tube with
a long valve stem to go through the
double wall and also avoid pressure on
the tube if stretched; these should be
available at better bike shops.
(I’ll admit that I used the existing
[standard stem] tube and tyre. It takes
a bit of manipulating but it is possible
to use a tube with a standard-length
valve stem).
Fit the gear cassette
When I was a kid, they used to be
called gear clusters – the multi-gear assembly for chain gears. A new one will
cost about $30 but we wanted to use
the existing one and save the money.
If you are doing so, you may need
help in removing it – there’s a special
tool which does the job in seconds. My
local bike shop did it for me without
charge. While you’ve got the gear cassette off, a good clean with some kero
and a wire brush won’t do any harm!
Fit brake disc (optional)
If your bike has disc brakes, there
is provision on the motorised rim for
fitting. Otherwise, you use the existing
caliper brakes but note that you may
need to reposition the shoes. In fact,
we found it easiest to remove the brakes
altogether while fitting the wheel – they
just get in the way.
Not only that, you’ll be fitting new
brake handles so will probably have to
replace the brake cables as well.
Loose spokes!
As we were examining the components, we were a little perturbed to
find most of the spokes in the wheel
rather loose. Apparently this is normal
practice to avoid the wheel warping
in transit (something we didn’t know
about).
With the aid of a spoke key ($6 at
the local bike shop) we proceeded to
tighten all the spokes before we went
any further.
The easiest way to do this is to use
an old front fork mounted vertically
(eg, in a vice). You’ll almost certainly
need to bend the forks apart a little to
accommodate the wider rear wheel
hub. Loosely mounting the wheel in
this fork will not only make access
simple but allow you to spin the wheel
easily, looking for any “wobbles” or
warped sections caused by too loose
or too tight spokes.
Remember that you tighten the
spokes on the opposite side of the warp
to pull the rim back to the centre.
You also need to ensure that the motor/axle is centrally located within the
rim. If the rim moves up and down as it
rotates, that needs to be corrected. You
tighten both sides by the same amount
to pull an eccentric (out-of-round) rim
back in. It’s a trial and error routine;
November 2011 17
Fitting the tube
and tyre is much
the same as a
“normal” bike
wheel. Rev-Bikes
suggest using a
tube with a long
valve stem, but
we elected to
use our old tyre
and tube. As
you can see the
valve stem pokes
through the
double-wall rim
with more than
enough length.
you may find that correcting a warp
results in the wheel being more eccentric – or vice versa.
Make small adjustments – no more
than half a turn at a time – and when
you think you’ve got it right, it’s best to
leave the wheel overnight (or at least a
few hours) to allow it to “settle”.
Fit the wheel
The powered wheel slots into position in the same way as the original.
However, you may need to pull the
frame apart slightly (maybe 10mm or
so) to fit the new wheel. It helps to
have a second person on hand to assist
with this.
The power and control wires exit
the hub on the left side (ie, the side
opposite the chain/gears). To keep them
from getting tangled in the wheel etc,
while building, loosely fasten them to
the frame with a cable tie.
It is important – in fact it’s vital with
a powered wheel – that the wheel nuts
are done up as tight as you can get them.
Ideally, you should use a ring spanner
or socket for this – don’t use a shifter
because they ruin far more nuts than
they do up!
It’s also vital that the wheel is placed
exactly on the centre line of the bike
– there should be exactly the same
distance between the rim and the frame
on both sides. This is no different to
any wheel you fit to a bike. Similarly,
the wheel should have no wobbles nor
eccentricities (see earlier notes).
Torque Bar
You might also consider the installation of a Torque Bar, which is designed
to ensure the axle doesn’t slip in the
forks. This is particularly necessary
18 Silicon Chip
They call them gear cassettes – this one came off
the original wheel and was easily fitted to the new
(powered) wheel – it simply screws on.
where high voltage motors are pulling
a lot of weight, or in certain kinds of
forks which don’t lock the axle in well.
These are also available from Rev Bikes
for $25.
Check the chain/gears
The gear changer (derailleur) is obviously fitted during the previous step
(under the axle nut) but before going
any further, check that it travels freely
and the chain also travel freely within
it and around the gears. Move the gear
lever so that the gears change from lowest to highest gear – a small adjustment
might be needed on the derailleur if
the actual gear positions are different
on the powered wheel.
Re-check tightness
We don’t want to harp on it but for
safety’s sake, go back and check that
the wheel nuts are still tight and that
the wheel hasn’t moved. While you’re
about it, check your front wheel nuts
too – you can’t be too careful.
Fit the battery plate to the
battery rack
The battery is designed to slide in
and out on a plate fixed to the battery
rack. Once in place, the key which
controls the bike locks the battery box
in place via a pin into the plate.
The battery plate fastens to the rack
via four 6mm screws with Nyloc nuts.
A washer under the head of each one
allows a little play until you get the
position correct.
Note that the hole in the plate (which
the pin mates with) goes toward the
front. This way the key is also towards
the front and the handle on the battery
box goes towards the rear.
Fit the battery rack
The two vertical bars screw into two
holes on the bike frame, immediately
adjacent to the axle. Most bikes these
days have these and they are invariably
tapped to 6mm.
The front of the rack connects to the
bike frame via two short extension arms
(in the kit) which can be adjusted foreand-aft to place the rack just where you
want it. They’re obviously intended for
bikes with horizontal holes through
the frame.
Where your frame doesn’t have suitable holes, the two extension arms need
to be secured to the frame, immediately
below the seat (saddle) stem. There’s
a variety of bike frame designs so you
will have to make the best arrangement
for your frame. Just remember that
the battery pack is one of the heavier
components – you certainly don’t want
it coming adrift as you’re riding along.
Fit the handlebar controls
Four “controls” need to be fitted to
the handlebars. The obvious one is the
throttle control/battery level indicator –
in our kit, it was a lever type but there
is also a twist-type available.
Whether you fit this to the right or
left is a matter of preference – we chose
the left side because it appeared to be
designed this way. Also, on a pushbike,
you should be giving hand signals
with your right hand, so your left hand
remains on the control/handlebar.
But how long is it since you’ve seen
a pushbike rider give a hand signal?
However, there is also an argument
for fitting it on the right because motorcycles and scooters usually have their
throttles on the right.
The second control is the cruise and
siliconchip.com.au
The battery tray bolts onto the battery rack,
which in turn is bolted to the bike frame. You
don’t want this coming loose while riding along!
The battery
packs a bit of
punch: 48V/12Ah!
The keyswitch not
only turns it on and
off but lowers a bolt
to secure it to the
battery tray.
horn buttons – these logically go on the
opposite side to the throttle.
The other two controls are the special
brake handles. As well as the mechanics for pulling the brake wire (just as
any brake handle) these also contain
a switch which engages regenerative
braking whenever the handles are
squeezed (ie, the motor becomes a
generator and returns some electrical
energy to the battery when braking).
To fit any of these controls, you’re
going to need to remove the handlebar
grips. If, as in our case, those grips
have been in place for a few years,
no amount of twisting or tugging will
remove them – we had to cut ours off
with a box cutter knife. Fortunately,
a new pair of grips is included in the
kit (NOTE: don’t fit the new ones until
you are absolutely sure of the position
of everything else!).
Another fly in the ointment could be
your chain gear shifter(s). On our bike,
the shifters were mounted close to the
grips – just where we wanted to mount
the throttle and cruise/horn buttons.
So we had to move them towards the
centre of the handlebars.
Mount everything just tight enough
to keep them in place – that way, you
can move everything around so that
nothing interferes with anything else.
Pay particular attention to the gear
shift levers, brake levers and throttle
controls – take them right through
their travels and adjust their positions
as necessary.
When you’re happy with the position
of all the handlebar controls, tighten
everything and secure the cables to the
handlebar post or frame with cable ties.
As a very last step – and possibly
only after you’ve ridden the bike for a
siliconchip.com.au
few hours – push the handlebar grips
into place. The reason this is the last
step is that they are rather difficult to
get off once on!
Connecting it all together
This section appears to be the most
challenging but is actually relatively
easy, as all the connectors are colour
coded. So all you have to do is connect
colour to colour and you shouldn’t go
astray.
The biggest problem you will have is
the length of the cable – it’s obviously
made to handle much longer bikes (a
tandem, perhaps?) and you will have
the best part of a metre too much.
It would be tempting to cut and resolder all the connectors so that the
right length of cable remained but we
thought that was tempting fate (and was
also too much like hard work!) so we
wrapped the excess cabling around the
underside of the battery rack and made
it as neat as possible with cable ties.
Also use cable ties to secure the
bunch of cables to the bike frame in as
many places as you want – just remember to keep clear of any bare brake or
gear changer cables.
Slide in the battery
The (now fully charged!) battery
pack slides onto the rack via the adaptor plate you fitted earlier. When it is
fully home, turning the power key on
the battery pack also lowers a “bolt”
through a matching hole in the adaptor
plate, locking it in place.
Finishing the cabling
Now it’s time to connect the control
cable and power cable. These mate with
the two cables emerging from the motor.
Make sure the key is in the off position before this step.
The control cable has a multi-way
connector. If you look closely, you’ll
see arrows on both plug and socket –
line up the arrows and the two halves
should mate easily. Push them all the
way home – they are waterproof when
fully engaged.
Be careful with this: it’s quite easy
to get them off alignment and if you do
(we did!) you’ll end up with bent pins
in the connector (we did!). This has
only one minor drawback: your bike
won’t work! (It didn’t!)
If you do manage to bend the pins,
you’re going to need a pair of very fine
needle nose pliers, a good magnifying
glass and a strong light.
Finally, connect the power cable, +
to + and – to –, to the only cable left
emerging from the motor. The opposite
end of this cable has a large plug which
connects to the battery output. It is
polarised but make sure you haven’t
forced it in the wrong way – again, it’s
+ to + and – to –.
We found that one of the connectors
in this plug had pushed too far back to
make reliable connection – a judicious
rearrangement with a pair of fine pliers
soon fixed this problem.
Checking it out
We know you’re itching to turn it on
and ride off into the sunset but before
you do, check (and tighten if necessary)
all Allen screws, Phillips screws, nuts,
etc – your safety depends on everything
being ship-shape. Most important
(again!) are the two nuts which hold
the powered wheel on – the motor
means there are very large stresses on
the wheel so tighten it up!
November 2011 19
The power and control
cables are fastened
securely to the bike frame
with cable ties.
The handlebar controls: on
the left, the throttle/battery
level meter behind the rear
brake lever (both new) and
gear lever; on the right the
bell and gear lever, with
the new cruise/horn button
and front brake lever.
Also tighten any cable ties fully and
snip their ends off, mainly for neatness
but also to ensure that any ends don’t
interfere with brakes or any of the controls. And it’s better to have too many
cable ties than not enough.
Boxing it up
A large box was supplied to contain
all of the cable connections, to keep
them out of the weather.
We thought this was a bit of overkill
and will be substituting a small jiffy
box instead; something unobtrusive
that will sit in front of the battery box.
Pedelec (PAS)
You may have noticed that we
haven’t bothered fitting the Pedelec
controller – that’s the device which
allows the motor to run only while the
pedals are being used. As mentioned
earlier, it’s a requirement in most, if not
all EU countries but it is not a requirement in this part of the world.
If you do want to fit it you’ll find fitting instructions on the website in the
section on Programming. As it’s not
required here, we didn’t bother with it.
Other “options”
You will notice on the lever throttle (which doubles as a battery level
indicator) that there is a push-button
switch with the word “lights” underneath. Similarly, on the other handlebar
control there are two push buttons; a
green button which is the cruise control
and a red button for a horn.
The cruise control is self explana-
Fig.1: this wiring diagram, taken from the Rev-Bikes
website, leaves a lot to be desired. Fortunately, the various
plugs and sockets are colour-coded so it’s reasonably
straightforward to connect everything.
20 Silicon Chip
tory – it works the same way as a cruise
control in a car. Once activated, it will
hold your speed (as best it can) at the
same level until you either push the
button again or activate either of the
brake handles.
The other two buttons are for options
– not surprisingly, they are for lights
and a horn. Because you have 48V
available, a very bright head and tail
light can be fitted, as can a much louder
horn than you’d expect on a pushbike.
The wiring diagram (Fig.1) shows
both these options and how they are
fitted; if you don’t have them don’t
worry – just ignore their fitting on the
diagram.
Programming
The electric motor should work with-
Fig.2: a screen grab of the programming software. It too is not
particularly user-friendly, especially when it comes to setting
that important power limit. As mentioned in the text, we’d be
inclined to set maximums to 25% and hope for the best!
siliconchip.com.au
?
The cables are far too long
so are securely wrapped
around and fastened to the
underside of the battery
rack, again with cable ties.
All the cables from the front of
the bike (handlebar controls)
mate with similarly-coloured
connectors at the rear.
out any programming on your part (ie,
with the factory defaults). However, if
you used the 1000W motor, it must be
re-programmed down via the supplied
USB cable before you can legally take
it on public roads.
Download the Cruise Controller
Programming Interface Software from
www.rev-bikes.com.
It’s a .rar file which you’ll need
to unpack, then load the resultant
“PI200Setup.exe” file and you’re away.
The USB cable plugs into the multipin connector which goes to the motor.
The screen should look something like
Fig.2 – and you can change any of the
parameters you want. The motor is
BLDC.
How do you set the power? If you
set the power to minimum we believe
you should be pretty close to the mark.
Theoretically, the minimum for a
1000W motor is 300W but if you allow
for less than 100% efficiency of the
motor – you’d have to be reasonably
close. As we mentioed earlier, no-one
has the means or equipment to measure
the motor output anyway!
Security
With around $1300 worth of motor
and battery, we imagine that an eBike
would be a juicy target for thieves.
Of course, you could chain and lock
your bike up when you leave it and
always remove the key (which locks
the battery box in place).
But we’d be more inclined, if at all
possible, to remove the battery box
completely and take it with you when
not in use. That will make it so much
harder for someone to purloin your
powered pushie!
Conclusion
It’s a wee ripper! Even programmed
down, on the flat the motor managed to
haul my 100kg around with apparent
ease and on hills, you certainly notice
the assistance from the motor.
The regenerative braking kicks in as
soon as you touch the brake handles –
it’s nice to know gravity is giving you
something back in the way of energy!
SC
WHERE FROM, HOW MUCH?
Our kit came from Rev-Bikes Pty Ltd, of
Melbourne, Vic. Phone (03) 9024 6653
Web: www.rev-bikes.com
Price for the “Offroad” Kit (wheel with
1000W motor, 48V battery pack &
charger, battery rack, controls and wiring) as seen here: .................. $1295.00
SPECIAL SILICON CHIP READER OFFER:
PIC TO COME
(FINISHED BIKE)
Order this kit from Rev-Bikes before December 9 (for guaranteed pre-Christmas
delivery) and they’ll give you a huge
discount, just for saying you saw the
article in SILICON CHIP!
That’s right: SILICON CHIP reader price is
just $1150.00
BUT WAIT, THERE’S MORE!
They’ll also throw in a FREE set of lights
with orders placed during November!
The finished eBike. Apart from tightening the spokes, total time to complete was
only a couple of hours. It’s still a standard mountain bike (albeit several kilos
heavier!) which can be ridden normally if the battery goes flat.
siliconchip.com.au
Many options and accessories are also
available such as a Solar Kit which charges
your battery while sitting in the sun. Price
is around $500 (depends on voltage).
See www.rev-bikes for more details.
November 2011 21
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