Chain Driven Dynamo

On 11/4/2015 5:44 PM, Joerg wrote:
On 2015-11-04 15:35, AMuzi wrote:
On 11/4/2015 5:20 PM, Jeff Liebermann wrote:
On Wed, 4 Nov 2015 09:43:59 -0800, sms

wrote:

Forget tire driven dynamos that wear out the sidewall of
the tire, or
expensive hub dynamos that require a new wheel.

http://www.aliexpress.com/item/Action-Bicycle-Dynamo-Chain-Dynamo-BICYCLE-GENERATOR-5V-Output-for-Mobile-Phone-MP3-Music-Angel-Flashlight/531798718.html



Ummm... I wonder how long the plastic thingy that keeps
the chain from
popping out of the dynamo sprocket will last? A problem
with all
chain and sprocket arrangements is that they only work
well if the
chain is partly wrapped around the sprocket. Any other
arrangement,
such as this linear configuration, results in the chain
trying to lift
itself away from the sprocket. Only the plastic thingy
keeps the
chain from skipping teeth or just skimming the tops of
the gear teeth.
Since the sprocket teeth are cut at about a 45 degree
angle, about
half of the chain drive force is directed perpendicular
to the
sprocket center, which then tries to pull the chain away
from the
sprocket.

The good news is that the dynamo doesn't produce much
power (maybe 10
watts for USB?), and therefore offers little resistance.
It's half
this force that produces the power, while the other half
tries to pull
the chain away from the sprocket, grind the chain into
the plastic
thingy, and produce some additional drag.

Instead of a plastic friction pad thiny, maybe a roller
or two
instead?


A roller? That's a great idea. Maybe it could run against
the tire?
Wonder why no one ever thought of that.


Do you know why roller dynamos fell from grace? In the 80's
they were all the rage with serious longhaul cyclists and
then some time in the 90's ... poof ... gone.


Because there are now other systems which suit other needs.
Celebrate diversity!

My needs aren't as intense in lumens as yours but I really
dislike batteries, charging etc. YMMV and usually does.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

John B. wrote:
On Thu, 05 Nov 2015 05:46:39 GMT, Ralph Barone
wrote:

James wrote:
On 05/11/15 09:20, Jeff Liebermann wrote:
On Wed, 4 Nov 2015 09:43:59 -0800, sms
wrote:

Forget tire driven dynamos that wear out the sidewall of the tire, or
expensive hub dynamos that require a new wheel.

http://www.aliexpress.com/item/Action-Bicycle-Dynamo-Chain-Dynamo-BICYCLE-GENERATOR-5V-Output-for-Mobile-Phone-MP3-Music-Angel-Flashlight/531798718.html

Ummm... I wonder how long the plastic thingy that keeps the chain from
popping out of the dynamo sprocket will last? A problem with all
chain and sprocket arrangements is that they only work well if the
chain is partly wrapped around the sprocket. Any other arrangement,
such as this linear configuration, results in the chain trying to lift
itself away from the sprocket. Only the plastic thingy keeps the
chain from skipping teeth or just skimming the tops of the gear teeth.
Since the sprocket teeth are cut at about a 45 degree angle, about
half of the chain drive force is directed perpendicular to the
sprocket center, which then tries to pull the chain away from the
sprocket.

The good news is that the dynamo doesn't produce much power (maybe 10
watts for USB?), and therefore offers little resistance. It's half
this force that produces the power, while the other half tries to pull
the chain away from the sprocket, grind the chain into the plastic
thingy, and produce some additional drag.

Instead of a plastic friction pad thiny, maybe a roller or two
instead?


Any bicycle with a rear derailleur already has a pair of sprockets with
the chain wrapped around. Could at least be used to keep the battery
charged that runs electronic gear shift mechanisms these days.


That makes some sense. After all, if you're not pedalling, you probably
have no need to shift, so the odds of matching power delivery and power
requirements looks good.

You missed the part about "used to keep the battery charged"?

--
cheers,

John B.



Actually, I didn't. I just failed to throw the word "average" into my text
a couple of times. The other nice thing is that if you want to charge a Di2
battery, there's already a wire going from the battery to the rear
derailleur.

On Thursday, November 5, 2015 at 1:54:40 PM UTC, Ralph Barone wrote:
John B. wrote:
On Thu, 05 Nov 2015 05:46:39 GMT, Ralph Barone
wrote:

James wrote:
On 05/11/15 09:20, Jeff Liebermann wrote:
On Wed, 4 Nov 2015 09:43:59 -0800, sms
wrote:

Forget tire driven dynamos that wear out the sidewall of the tire, or
expensive hub dynamos that require a new wheel.

http://www.aliexpress.com/item/Action-Bicycle-Dynamo-Chain-Dynamo-BICYCLE-GENERATOR-5V-Output-for-Mobile-Phone-MP3-Music-Angel-Flashlight/531798718.html

Ummm... I wonder how long the plastic thingy that keeps the chain from
popping out of the dynamo sprocket will last? A problem with all
chain and sprocket arrangements is that they only work well if the
chain is partly wrapped around the sprocket. Any other arrangement,
such as this linear configuration, results in the chain trying to lift
itself away from the sprocket. Only the plastic thingy keeps the
chain from skipping teeth or just skimming the tops of the gear teeth.
Since the sprocket teeth are cut at about a 45 degree angle, about
half of the chain drive force is directed perpendicular to the
sprocket center, which then tries to pull the chain away from the
sprocket.

The good news is that the dynamo doesn't produce much power (maybe 10
watts for USB?), and therefore offers little resistance. It's half
this force that produces the power, while the other half tries to pull
the chain away from the sprocket, grind the chain into the plastic
thingy, and produce some additional drag.

Instead of a plastic friction pad thiny, maybe a roller or two
instead?


Any bicycle with a rear derailleur already has a pair of sprockets with
the chain wrapped around. Could at least be used to keep the battery
charged that runs electronic gear shift mechanisms these days.


That makes some sense. After all, if you're not pedalling, you probably
have no need to shift, so the odds of matching power delivery and power
requirements looks good.

You missed the part about "used to keep the battery charged"?

--
cheers,

John B.



Actually, I didn't. I just failed to throw the word "average" into my text
a couple of times. The other nice thing is that if you want to charge a Di2
battery, there's already a wire going from the battery to the rear
derailleur.

Mmm. I was perfectly happy with the hub dynamo charging the full Di2 system (fully automatic electronic gear shifting, not the cut-down manual assisted gears on the DuraAce for roadies, active electronic suspension, light sensor management, control programs for various purposes) on my Trek Smover. Everything worked transparently and faultlessly. But itself the auto gears made me about 10% faster over a loop I rode daily because I was always in the right gear. A crappy generator, like Scharfie is pushing, would have ruined a good system by supplying juice only intermittently.

Andre Jute
Context is everything

On 2015-11-04 18:31, sms wrote:
On 11/4/2015 3:44 PM, Joerg wrote:

Do you know why roller dynamos fell from grace? In the 80's they were
all the rage with serious longhaul cyclists and then some time in the
90's ... poof ... gone.

My touring bicycle even had internal wiring for a bottom bracket roller
dynamo. The Sanyo roller dynamo made a brief reappearance a couple of
years ago, then disappeared again
http://www.peterwhitecycles.com/images/products/Lights/sant110bb.jpg.

There's a crude looking one available again, see
http://www.amazon.com/dp/B00Q8770WU.


That one doesn't exactly instill confidence about longevity :-)

--
Regards, Joerg

http://www.analogconsultants.com/

On 2015-11-05 03:06, Lou Holtman wrote:
On Thursday, November 5, 2015 at 12:44:51 AM UTC+1, Joerg wrote:
On 2015-11-04 15:35, AMuzi wrote:
On 11/4/2015 5:20 PM, Jeff Liebermann wrote:
On Wed, 4 Nov 2015 09:43:59 -0800, sms
wrote:

Forget tire driven dynamos that wear out the sidewall of the
tire, or expensive hub dynamos that require a new wheel.

http://www.aliexpress.com/item/Action-Bicycle-Dynamo-Chain-Dynamo-BICYCLE-GENERATOR-5V-Output-for-Mobile-Phone-MP3-Music-Angel-Flashlight/531798718.html




Ummm... I wonder how long the plastic thingy that keeps the chain from
popping out of the dynamo sprocket will last? A problem with
all chain and sprocket arrangements is that they only work well
if the chain is partly wrapped around the sprocket. Any other
arrangement, such as this linear configuration, results in the
chain trying to lift itself away from the sprocket. Only the
plastic thingy keeps the chain from skipping teeth or just
skimming the tops of the gear teeth. Since the sprocket teeth
are cut at about a 45 degree angle, about half of the chain
drive force is directed perpendicular to the sprocket center,
which then tries to pull the chain away from the sprocket.

The good news is that the dynamo doesn't produce much power
(maybe 10 watts for USB?), and therefore offers little
resistance. It's half this force that produces the power,
while the other half tries to pull the chain away from the
sprocket, grind the chain into the plastic thingy, and produce
some additional drag.

Instead of a plastic friction pad thiny, maybe a roller or two
instead?


A roller? That's a great idea. Maybe it could run against the
tire? Wonder why no one ever thought of that.


Do you know why roller dynamos fell from grace? In the 80's they
were all the rage with serious longhaul cyclists and then some time
in the 90's ... poof ... gone.

-- Regards, Joerg

http://www.analogconsultants.com/

That was because hub dyno's became available for a fair price, a much
better solution....


Doesn't apply to bicycles with really good brakes, a.k.a. disc brakes.
Then the "solution" is a SON hub dynamo which sets you back over $200
with new spokes and all. Of course, then there is also the flooding
issue with MTB which battery lights and bottle dynamos do not have.


... Here we were glad we got rid of the bottle dyno's
which today only are used in cheap 'Walmart' bikes.


Have you ever been in a Walmart or did you just make that up? I have
never seen a bike in a Walmart that had a bottle dynamo.

--
Regards, Joerg

http://www.analogconsultants.com/

On 2015-11-05 05:17, AMuzi wrote:
On 11/4/2015 5:44 PM, Joerg wrote:
On 2015-11-04 15:35, AMuzi wrote:
On 11/4/2015 5:20 PM, Jeff Liebermann wrote:
On Wed, 4 Nov 2015 09:43:59 -0800, sms

wrote:

Forget tire driven dynamos that wear out the sidewall of
the tire, or
expensive hub dynamos that require a new wheel.

http://www.aliexpress.com/item/Action-Bicycle-Dynamo-Chain-Dynamo-BICYCLE-GENERATOR-5V-Output-for-Mobile-Phone-MP3-Music-Angel-Flashlight/531798718.html




Ummm... I wonder how long the plastic thingy that keeps
the chain from
popping out of the dynamo sprocket will last? A problem
with all
chain and sprocket arrangements is that they only work
well if the
chain is partly wrapped around the sprocket. Any other
arrangement,
such as this linear configuration, results in the chain
trying to lift
itself away from the sprocket. Only the plastic thingy
keeps the
chain from skipping teeth or just skimming the tops of
the gear teeth.
Since the sprocket teeth are cut at about a 45 degree
angle, about
half of the chain drive force is directed perpendicular
to the
sprocket center, which then tries to pull the chain away
from the
sprocket.

The good news is that the dynamo doesn't produce much
power (maybe 10
watts for USB?), and therefore offers little resistance.
It's half
this force that produces the power, while the other half
tries to pull
the chain away from the sprocket, grind the chain into
the plastic
thingy, and produce some additional drag.

Instead of a plastic friction pad thiny, maybe a roller
or two
instead?


A roller? That's a great idea. Maybe it could run against
the tire?
Wonder why no one ever thought of that.


Do you know why roller dynamos fell from grace? In the 80's
they were all the rage with serious longhaul cyclists and
then some time in the 90's ... poof ... gone.


Because there are now other systems which suit other needs.
Celebrate diversity!

My needs aren't as intense in lumens as yours but I really dislike
batteries, charging etc. YMMV and usually does.


Yeah, I guess that's true. Looks like I'll have to install a bigger
battery also for the road bike. On the MTB I now have well over 50
watt-hours available which allows 5h+ rides with the lights on.

Luckily I just found a gray junction box at Home Depot that can
accommodate eight 18650 cells so they no longer have to ride in the rack
trunk. Requires lots of adaptation and drilling but once it's done I
have a solid battery compartment.

Then I am going to see if I can mod a classic Spanninga rear light with
a Lumileds style 3W LED but operated only at around 1W. I have
squirreled some of those lights before moving to the US, comes in handy now.

--
Regards, Joerg

http://www.analogconsultants.com/

On Thu, 05 Nov 2015 07:17:11 -0600, AMuzi wrote:

Because there are now other systems which suit other needs.
Celebrate diversity!

I think you now understand how marketing works. Once a need is
satisfied, marketing simply creates a new unsatisfied need, convinces
potential buyers that they are not proper cyclists without satisfying
the new need, and of course provides a series of defective products
that partly satisfy the need, but only if one buys the latest
incremental upgrades.

My needs aren't as intense in lumens as yours but I really
dislike batteries, charging etc. YMMV and usually does.

Would liquid fuel help? There are kerosene and acetylene bicycle
lanterns available. Figure about 80 lumens.
https://www.google.com/search?q=antique+bicycle+lantern&tbm=isch
Please note that they are also useful for personal protection by
simply inverting the lantern into the Molotov Cocktail mode.

You seem to have a pathological aversion to batteries, I have a simple
solution. It's a common problem worthy of a solution. Welcome to
Jeff's Battery Exchange Service(tm) or JBES. JBES offers to perform
all the messy, awkward, dangerous, and tedious battery charging and
maintenance service for you. Merely purchase a collection of Jeff's
Sealed Battery Containers(tm) or JSBC and use them to power your
riding experience. When the JSBC is depleted, merely insert the JSBC
in the supplied mailing container, and send it to the nearest Jeff's
Battery Service Center(tm) or JBSC. Upon confirmation of shipment,
the JBSC will mail you a fully charged and tested replacement battery,
thus eliminating the need to even look at a battery, much less
actually handle one directly. Of course, investors, franchise
operators, pyramid schemers, and operators of additional JBSC
facilities are always welcome.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Thu, 5 Nov 2015 15:19:18 +1000, James
wrote:

Any bicycle with a rear derailleur already has a pair of sprockets with
the chain wrapped around. Could at least be used to keep the battery
charged that runs electronic gear shift mechanisms these days.

Won't work. All the power from pedaling is tranfered from the crank
to the freewheel through the chain. The return chain path, which
includes the derailleur, has no chain tension, no power, and cannot be
used to power a generator or dynamo.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 11/5/2015 9:49 AM, Jeff Liebermann wrote:
On Thu, 05 Nov 2015 07:17:11 -0600, AMuzi wrote:

Because there are now other systems which suit other needs.
Celebrate diversity!

I think you now understand how marketing works. Once a need is
satisfied, marketing simply creates a new unsatisfied need, convinces
potential buyers that they are not proper cyclists without satisfying
the new need, and of course provides a series of defective products
that partly satisfy the need, but only if one buys the latest
incremental upgrades.

My needs aren't as intense in lumens as yours but I really
dislike batteries, charging etc. YMMV and usually does.

Would liquid fuel help? There are kerosene and acetylene bicycle
lanterns available. Figure about 80 lumens.
https://www.google.com/search?q=antique+bicycle+lantern&tbm=isch
Please note that they are also useful for personal protection by
simply inverting the lantern into the Molotov Cocktail mode.

You seem to have a pathological aversion to batteries, I have a simple
solution. It's a common problem worthy of a solution. Welcome to
Jeff's Battery Exchange Service(tm) or JBES. JBES offers to perform
all the messy, awkward, dangerous, and tedious battery charging and
maintenance service for you. Merely purchase a collection of Jeff's
Sealed Battery Containers(tm) or JSBC and use them to power your
riding experience. When the JSBC is depleted, merely insert the JSBC
in the supplied mailing container, and send it to the nearest Jeff's
Battery Service Center(tm) or JBSC. Upon confirmation of shipment,
the JBSC will mail you a fully charged and tested replacement battery,
thus eliminating the need to even look at a battery, much less
actually handle one directly. Of course, investors, franchise
operators, pyramid schemers, and operators of additional JBSC
facilities are always welcome.


I just want to go ride my bike, any time[1], without
thinking about it. Both my urban bikes have dynamos (one
hub, one bottle) neither of which consume any thought or
attention whatsoever. Again I'm not proselytizing but truly
people's various criteria differ and so their decisions vary
in outcome.

[1] One of my most satisfying adventures for 2015 was waking
up at 3am in early August. I rode down to the lake and laid
in the grass watching meteors for a couple hours.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 2015-11-05 15:09:58 +0000, Joerg said:

On 2015-11-05 03:06, Lou Holtman wrote:
On Thursday, November 5, 2015 at 12:44:51 AM UTC+1, Joerg wrote:
On 2015-11-04 15:35, AMuzi wrote:
On 11/4/2015 5:20 PM, Jeff Liebermann wrote:
On Wed, 4 Nov 2015 09:43:59 -0800, sms
wrote:

Forget tire driven dynamos that wear out the sidewall of the
tire, or expensive hub dynamos that require a new wheel.

http://www.aliexpress.com/item/Action-Bicycle-Dynamo-Chain-Dynamo-BICYCLE-GENERATOR-5V-Output-for-Mobile-Phone-MP3-Music-Angel-Flashlight/531798718.html





Ummm... I wonder how long the plastic thingy that keeps the chain from
popping out of the dynamo sprocket will last? A problem with
all chain and sprocket arrangements is that they only work well
if the chain is partly wrapped around the sprocket. Any other
arrangement, such as this linear configuration, results in the
chain trying to lift itself away from the sprocket. Only the
plastic thingy keeps the chain from skipping teeth or just
skimming the tops of the gear teeth. Since the sprocket teeth
are cut at about a 45 degree angle, about half of the chain
drive force is directed perpendicular to the sprocket center,
which then tries to pull the chain away from the sprocket.

The good news is that the dynamo doesn't produce much power
(maybe 10 watts for USB?), and therefore offers little
resistance. It's half this force that produces the power,
while the other half tries to pull the chain away from the
sprocket, grind the chain into the plastic thingy, and produce
some additional drag.

Instead of a plastic friction pad thiny, maybe a roller or two
instead?


A roller? That's a great idea. Maybe it could run against the
tire? Wonder why no one ever thought of that.


Do you know why roller dynamos fell from grace? In the 80's they
were all the rage with serious longhaul cyclists and then some time
in the 90's ... poof ... gone.

-- Regards, Joerg

http://www.analogconsultants.com/

That was because hub dyno's became available for a fair price, a much
better solution....


Doesn't apply to bicycles with really good brakes, a.k.a. disc brakes.
Then the "solution" is a SON hub dynamo which sets you back over $200
with new spokes and all. Of course, then there is also the flooding
issue with MTB which battery lights and bottle dynamos do not have.

Huh..?
https://www.bike-components.de/en/Sh...H-T675-p33665/


I think a dyno hub can handle with some wet conditions as a normal hub
does. I would not recommend to ride in hub deep water though which
never happens besides liberately doing that. I would comfortable riding
with a hub dyno equipped ATB here off road.



... Here we were glad we got rid of the bottle dyno's
which today only are used in cheap 'Walmart' bikes.


Have you ever been in a Walmart or did you just make that up? I have
never seen a bike in a Walmart that had a bottle dynamo.

By putting Walmart between ' ' I meant department store bikes. I
thought you would understand that.



--

Lou