# [EVDL] Promoting the use of eBikes



## EVDL List (Jul 27, 2007)

*Promoting the Use of eBikes*



I am interested in promoting the use of electric bicycles, or e-bikes. My
interest in e-bikes

lies not in terms of sport (although I find e-bikes WAY more fun than
conventional bikes), or

exercise (even though they extend exercise to a much larger group of people
than conventional

bikes), but as practical short range transportation, as the most energy and
materials

efficient form of transportation known to man or nature, and therefore a
partial solution to

many problems ranging from climate change to national defense.



Because of this I want to be sure that the information I provide about
e-bikes is accurate and

reasonable. I have some observations on e-bikes that I would like to test
with a larger

audience to see to what extent I need to modify my views.



*My experience with e-bikes includes*:



(1) a Dahon Mariner 7 folding bike with 20 inch wheels, to which I have
added a 350 watt

BIONx PL350 gear-less motor and 350 WH battery. The complete bike with
battery and motor weighs

46 lbs. I have over 1800 miles on it.



(2) An R-Martin 350 watt mid-drive motor (with a worm gear) bike with 26
inch wheels. It

weighs 59 lbs. and I have over 200 miles on it. The motor makes full use of
the

derailleur gears.



(3) Test drives of a 250 watt front hub motor (with planetary gears) on a
bike with 20 inch

wheels



(4) Test drives of a 350 watt motor (with a planetary gear) on a 26 inch
wheel bike.



(5) Numerous conversations with e-bike riders along with Internet newsgroups
and email.



The desirable goal is an affordable, lightweight, low maintenance, safe
ebike with excellent

hill-climbing ability, that can attain the legal speed (19 mph) under power,
is quiet, and

has reasonable range (15+ miles) with only "pleasant-no-sweat" pedaling over
realistic hilly

terrain.



*Here are some of my observations:*



[1] Front hub motor vs rear hub motor: on a conventional bike, the best
weight distribution

is 60% rear and 40% front. Since the motor and (LiON) battery weigh about
the same, a font

hub motor would have these advantages: (a) the weight distribution remains
the same, and (b)

the motor is MUCH easier to install or remove. The disadvantages are (a)
less traction and

(b) heavier steering. Rear hub motors have the advantage of more traction
on hills, but have

the disadvantages of (a) greater weight distribution on the rear (unless the
battery is

located in the front, a configuration I have not seen), and (b) much more
difficult

installation and removal. Since hill climbing ability/traction is important,
I lean toward

rear hub motors, but I welcome other views.





[2] 20 inch wheels versus 26 inch wheels and hill climbing ability: On my 20
inch wheel Dahon

with 350 watt hub motor I can climb 14% grade hills at about 9 MPH in high
gear with

"pleasant-no-sweat" pedaling. The 20 inch wheel lets you climb 30% steeper
hills than 26 inch

wheels, and for a city like Seattle (where I live), 350 watts is the minimum
power to handle

typical hills for a 20 inch wheel bike.



I find 250 watts wholly inadequate even for 20 inch wheels. Since 350 watts
on a 26 inch wheel

bike is similar to 250 watts on a 20 inch bike (for hill climbing, that is),
500 watts is the

minimum acceptable power on a 26 inch wheel bike, unless it is a mid-drive
bike which fully uses

the derailleur (on my R-Martin mid-drive, its 350 watt motor in low gear can
climb a 14% grade at

about 3.9 MPH with no pedaling and about 4.5 MPH with "pleasant-no-sweat"
pedaling, but it is

always slower on hills (about 2/3 the speed) than my 350 watt hub motor 20
inch Dahon)



[3] Hub motor versus mid-drive: hub motors do not make use of the bicycle
gears, and if the

motor/wheel combination is sufficiently powerful, you normally never need to
change gears: I

usually just press the throttle on my 350 watt Dahon and do
"pleasant-no-sweat" pedaling and

cruise along at 18 MPH and pedal the same whether I am on the level or going
up steep hills. The

only time I need to change gears is on a VERY steep hill (18% grade or more,
which is fortunately

very rare), or if I am forced to travel very slowly because the throttle on
a BIONx motor is only

"all-or-nothing" (if the throttle had low-medium-high power levels I would
probably not need to

change gears at low speeds). Also, gear-less hub motors allow regenerative
braking which is

very effective for slowing down and provides a small (perhaps 10%) but
useful extension in

range



A 350 watt mid-drive motor is sufficient for 26 inch wheel bikes (though
slow on steep hills),

but it requires constant gear changing, and this means that the motor must
be disengaged when

power off when changing gears, because when the power is on, any pedaling
automatically

engages the motor and causes very hard and damaging shifts. But even
without that flaw the

frequent need to shift gears and the high maintenance of derailleurs is a
problem. So I

favor the hub motor design.



[4] Geared versus gear-less hub motors: geared hub motors have an advantage
in torque and

efficiency at climbing steep hills at low speeds (or starting up a steep
hill from a stop),

but once a reasonable speed is achieved, gear-less hub motors are as
effective. More

importantly, gear-less hub motors are totally silent, are slightly more
efficient at moderate

and higher speeds, and last much longer and need much less maintenance as
they have but one

moving part. In addition, gear-less hub motors allow for regenerative
braking, which I have

not seen on any geared motor. So I lean toward a gear-less motors and would
add more wattage

to compensate for the lesser low speed torque.



[5] 20 inch versus 26 inch wheel e-bikes: 20 inch wheel bikes have one major
disadvantage:

they are much less stable than 26 inch bikes (at least the 3 such bikes I
have tried). It is

rather scary to ride with only one hand on the handlebars, and I suspect
even one second with

climbing, and much easier transport and storage. 26 inch wheel bikes are
much more stable,

and possibly more comfortable, but require a large motor and are much more
difficult to

transport and store.





[6] My ideal folding eBike would be a 20 inch wheel bike with a 350 watt
gear-less hub motor,

rear regenerative disk brakes, a 400 WH LiON battery mounted between seat
and handlebars,

with a fixed gear (no derailleur), easily removable pedals (NOT fold able
but removable) to

make folding the bike easier, puncture proof tires, and a 3-speed throttle.
This

configuration would create a very low maintenance bike, as the motor has but
one moving part,

the load on the sprocket-chain would be very low (since the motor does most
of the work), and

the rear regenerative disk brake would last much longer than pure friction
brakes.


-- 
Larry Gales
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## EVDL List (Jul 27, 2007)

> Larry Gales wrote:
> > *Promoting the Use of eBikes*
> >
> >
> ...


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## EVDL List (Jul 27, 2007)

You should look at electric tadpole trikes. We've been making them for the shell ecomarathon for 2 years now

Michael Golub
Univ alaska Fairbanks 

Sent from my iPhone



> Willie McKemie <[email protected]> wrote:
> 
> > On Fri, Jul 15, 2011 at 11:34:30PM -0700, Larry Gales wrote:
> >> *Promoting the Use of eBikes*
> ...


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## EVDL List (Jul 27, 2007)

I'm surprised no one has mentioned <a
href="http://endless-sphere.com/forums/index.php?sid=f118e9ce37923b3b7ce2e570468844ae"

--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Promoting-the-use-of-eBikes-tp3671487p4655730.html
Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.

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## EVDL List (Jul 27, 2007)

> Larry Gales wrote:
> > I did confuse power with torque: the smaller wheel acts like a gear
> > reduction, and if you don't compensate somewhere else, such as a gear in
> > the motor, you will lose torque.
> ...


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## EVDL List (Jul 27, 2007)

Yes, a smaller wheel means more torque but less speed. I thnk that the main
reason the 20 inch BIONx/Dahon is faster going up hills, is that the 350
watt motor becomes a 700 watt motor for the duration of the hill.

-- Larry



> Robert Johnston <[email protected]> wrote:
> 
> > On Saturday, June 16, 2012 1:13:41 PM, Larry Gales wrote:
> > > I did confuse power with torque: the smaller wheel acts like a gear
> ...


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## EVDL List (Jul 27, 2007)

I fully agree that E-Bikes at present are rather crude. I love my
BIONx/Dahon, but it has a number of flaws, such as the fact that the
battery could be easier to remove/install, that the bike is not fully
rain-proof, that the throttle is all-or-nothing, that the weigh
distribution is poor, etc.

I would really like to see some group with resources, who would see e_bikes
as serious transportation, do thorough design studies to come up with
simple, lightweight, and sufficiently powerful designs for a variety of
e-bike types, which could be mass produced for reasonable $$s.

I have often wondered if some environmental groups, such as the Sierra
Club, would be willing to invest some resources there.

-- Larry




> Lee Hart <[email protected]> wrote:
> 
> > On 7/16/2011 1:34 AM, Larry Gales wrote:
> > > *Promoting the Use of eBikes*
> ...


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## EVDL List (Jul 27, 2007)

I have a nice hybrid Lithium-Ion E-bike scooter that my boss is letting me 
use for a while , it is a 2012 Extreme scooter. I don't know how much 
voltage it is but it will go 20 mph on flat land & 25 down hill. It has a 
range of about 38 miles. It also has removable pedals so it is a E-Bike & 
can go on the bike trails. sidewalks, streets, anywhere & everywhere! it's a 
blast to drive!! I have never seen a scooter like this before. $1800 new!

-----Original Message----- 
From: Robert Johnston
Sent: Saturday, June 16, 2012 8:47 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Promoting the use of eBikes



> Larry Gales wrote:
> > I did confuse power with torque: the smaller wheel acts like a gear
> > reduction, and if you don't compensate somewhere else, such as a gear in
> > the motor, you will lose torque.
> ...


----------



## EVDL List (Jul 27, 2007)

Strange that I did not get Lee's message, only see it because
Larry is replying to it... No problem with other messages
from Lee around that time, such as the New A123 LiFePO4 reply.

Anyway - why would you remove a wheel to repair a flat?
I always turn the bike upside down, lift the tire from
the rim and pull the tube out, pump it a bit, find the hole
and patch it (mark the location, sand the tube around the
hole, deflate the tube and put a thin layer of glue larger 
than the size of the patch on the sanded area around the hole.
Wait till the glue is almost dry then apply the patch). 
Then pump the tire again a little bit (its diameter 
should stay smaller than the tire) so it will automatically 
stay inside the tire when you put it back on the rim, 
otherwise you might catch the tube between the rim and 
your tools and cut it.
Go around the wheel and sqeeze the tire to make sure that
it is properly seated and the tube did not catch anywhere,
turn the bike upright and pump the tire, off you go again.

My father taught me this and I have been patching uncounted
dozens of punctures over the last 40 years...

BTW, in the last years I have started using slime in the tubes
(buy a big bottle and squeeze a little in each tire) to allow
me to ignore the small puntures for a while. California has
areas where you get flats so often that it is unreasonable to
patch every hole, you might have days that you ride on the
shoulder of a road and suddenly a dozen "punture vine" pods are
attached to your tire with the thorn in your tire. When you
have slime in the tube then you simply pull all thorns out,
you might see some green bubbles but you can continue your
ride without losing much of the pressure in your tire, at
least most of the time.

BTW, I like hub motors because their large diameter allows
them to have good cooling and enough torque to run without
gearing down, only a one-way clutch to allow freewheeling
when pedaling without motor engagement or even power to the
controller...

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water XoIP: +31877841130
Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203 

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Larry Gales
Sent: Saturday, June 16, 2012 7:51 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Promoting the use of eBikes

I fully agree that E-Bikes at present are rather crude. I love my
BIONx/Dahon, but it has a number of flaws, such as the fact that the
battery could be easier to remove/install, that the bike is not fully
rain-proof, that the throttle is all-or-nothing, that the weigh
distribution is poor, etc.

I would really like to see some group with resources, who would see
e_bikes as serious transportation, do thorough design studies to come up
with simple, lightweight, and sufficiently powerful designs for a
variety of e-bike types, which could be mass produced for reasonable
$$s.

I have often wondered if some environmental groups, such as the Sierra
Club, would be willing to invest some resources there.

-- Larry


On Sat, Jul 16, 2011 at 11:52 AM, Lee Hart <[email protected]>


> wrote:
> 
> > On 7/16/2011 1:34 AM, Larry Gales
> 
> ...


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## EVDL List (Jul 27, 2007)

Indeed, Endless Sphere has a lot of bike discussion,
including dedicated technical forum discussions. 


Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water XoIP: +31877841130
Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203 

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of salty9
Sent: Saturday, June 16, 2012 10:01 AM
To: [email protected]
Subject: Re: [EVDL] Promoting the use of eBikes

I'm surprised no one has mentioned <a
href="http://endless-sphere.com/forums/index.php?sid=f118e9ce37923b3b7ce
2e570468844ae"

--
View this message in context:
http://electric-vehicle-discussion-list.413529.n4.nabble.com/Promoting-t
he-use-of-eBikes-tp3671487p4655730.html
Sent from the Electric Vehicle Discussion List mailing list archive at
Nabble.com.

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