Dynamo lighting

Can anyone give me -in layman's terms-the extra effort required to propel
your bike with a typical tyre-driven dynamo? Thanks i.a.
Rob

On Dec 23, 4:59*am, "Robert Norton" wrote:
Can anyone give me -in layman's terms-the extra effort required to propel
your bike with a typical tyre-driven dynamo? *Thanks i.a.
Rob

Hopefully these things have improved over the years. I haven't seen
one since my childhood days, as I remember they didn't provide much
light.

Eric

On Dec 23, 9:01*am, bluezfolk wrote:
On Dec 23, 4:59*am, "Robert Norton" wrote:

Can anyone give me -in layman's terms-the extra effort required to propel
your bike with a typical tyre-driven dynamo? *Thanks i.a.
Rob

Hopefully these things have improved over the years. *I haven't seen
one since my childhood days, as I remember they didn't provide much
light.

http://www.myra-simon.com/bike/dynamos.html

There are instructions online for building your own.
http://www.instructables.com/id/Dyna...D_bike_lights/

This guy's stuff is tops.
http://ktronik.com/LED.html
http://ktronik.com/beamshots.html

This flashing bike light is powered through magnetic induction, so
friction isn't an issue. The rotating weight would be small, so I
don't think you'd ever notice the difference in spinning your wheel up
to speed.
http://www.youtube.com/watch?v=IGjH2bXOvxg

R

on 23-12-2008, bluezfolk supposed :
On Dec 23, 4:59*am, "Robert Norton" wrote:
Can anyone give me -in layman's terms-the extra effort required to propel
your bike with a typical tyre-driven dynamo? *Thanks i.a.
Rob

Hopefully these things have improved over the years. I haven't seen
one since my childhood days, as I remember they didn't provide much
light.

Eric

Just come over to the Netherlands and be amazed about the number of
tyre-driven dynamo's here.

Superior to battery powered front lights.

Not to say the hub-dynamos, which are übersuperior!

Martin

My recollection is they provided strong dependable light but only if you
kept moving of course. the pproblem is the drag hence my question.
r
"RicodJour" wrote in message
...
On Dec 23, 9:01 am, bluezfolk wrote:
On Dec 23, 4:59 am, "Robert Norton" wrote:

Can anyone give me -in layman's terms-the extra effort required to
propel
your bike with a typical tyre-driven dynamo? Thanks i.a.
Rob

Hopefully these things have improved over the years. I haven't seen
one since my childhood days, as I remember they didn't provide much
light.

http://www.myra-simon.com/bike/dynamos.html

There are instructions online for building your own.
http://www.instructables.com/id/Dyna...D_bike_lights/

This guy's stuff is tops.
http://ktronik.com/LED.html
http://ktronik.com/beamshots.html

This flashing bike light is powered through magnetic induction, so
friction isn't an issue. The rotating weight would be small, so I
don't think you'd ever notice the difference in spinning your wheel up
to speed.
http://www.youtube.com/watch?v=IGjH2bXOvxg

R

On Tue, 23 Dec 2008 09:59:16 +0000, Robert Norton wrote:

Can anyone give me -in layman's terms-the extra effort required to propel
your bike with a typical tyre-driven dynamo? Thanks i.a.

About 10 watts input for 6Watts output.

Like 2% of max output of a peak bicyclists, or 10% of ell-tubbie.

The old bottle generators that rubbed on the outside of the wheel teneded
to be a noticeable drag.

and as mentioned in your other post, if you didn't manage 10mph minimum,
the light was pathetic.

Next step up was Sanyo and oter mobs who made a version that ran on the
outside of the wheel and these had less drag. same speed problems into an
incandescent type buld.

Sturney Archers and others made hub generators which had less drag, but
had a noticeable cogging effect. Again, same speed problem.

Nowadays, LEDs promise a lot, but still have a way to go. Aka, I'm still
going to have my 50Watt MR16(?) running off my SLA battery for busy road
work.

The major advance is that use of switch mode power supplies can boose
voltage at low speeds and over come the dullness, but also handle high
speed downhill. Designing and building these can be done by the hobbiest.

and, battery tchnology can help you out, if you have the cash to buy NiMh,
etc

In article ,
terryc wrote:

On Tue, 23 Dec 2008 09:59:16 +0000, Robert Norton wrote:

Can anyone give me -in layman's terms-the extra effort required to
propel your bike with a typical tyre-driven dynamo? Thanks i.a.

About 10 watts input for 6Watts output.

Like 2% of max output of a peak bicyclists, or 10% of ell-tubbie.

I'm not sure that those are "layman's terms" nor are they all that
accurate. For one thing, the output of bicycle dynamos is 3W at 6V, not
6W. A Schmidt SON dynamo hub is about 65% efficient so it costs about
5W to the cyclist to produce 3W. You had the proportions right, though.

A "peak bicyclist" (by which I assume you mean a cyclist in competitive
condition) can output far more than 200W- more like 1000-1400W in a
maximal sprint and 400W sustained. But those folks aren't usually
riding with dynamos, except for competitive randonneurs and maybe not
even them. The serious cycling enthusiast probably has a maximum
sustained output around 300W (making the energy cost about 1.7%). El
Tubbie the occasional cyclist might have a sustained output of 200W or
less (so about 2.5%).

My experience is that my Schmidt hub dynamo is imperceptible in terms of
adding to the effort of cycling whether the light is on or off. The
comparison made a number of years ago was that the hub adds about the
amount of effort of climbing 1 foot in a mile.

My experience with a Sanyo bottom bracket dynamo is that it too is
barely perceptible in use and, of course, add no drag when turned off.
I haven't used a sidewall dynamo since I was in high school; I remember
that one (a Union, probably) being a bit draggy.

Here's some information about bicycle lighting:

http://www.peterwhitecycles.com/lightingsystems.htm

http://en.wikipedia.org/wiki/Hub_dynamo

::
:: Just come over to the Netherlands and be amazed about the number of
:: tyre-driven dynamo's here.
::
:: Superior to battery powered front lights.
::
:: Not to say the hub-dynamos, which are übersuperior!
::
:: Martin

Yes, especially when going up all of those hills!

Pat in TX