Dynohub drag

On Wed, 08 Oct 2014 23:33:29 +0100, Clive George
wrote:

On 08/10/2014 22:16, wrote:
On Wed, 08 Oct 2014 13:04:31 -0700, sms
wrote:

On 10/8/2014 12:19 PM, wrote:

Any hub dyno with have slightly more drag with the light off, and a
whole lot less drag with the light on when compared to useing a
"bottle" dyno friction driven off the tire - which WAS the normal way
of powering headlights a few decades ago if you didn't want to use
batteries.(and rechargeables were not a viable option back then)

Actually there were several rechargeable systems back then.

http://www.bikeforums.net/electronics-lighting-gadgets/837931-archives-defunct-bicycle-lighting-company.html
was the most famous one.
I was talking FOUR decades ago. The first rechargeable flashlight was
only introduced in 1968, so rechargeable batteries were far from
common in the mid to late sixties.

What did cars use? :-)

Miners and hence cavers used NiFe cells or lead acids. I agree that
later on NiCds started taking over, but that was late 80s.

Of course now people have a helmet mounted LED and battery which is
almost smaller than the lamp alone, let alone the lumping great battery
pack one had strapped to one's waist. More light, for longer. And
potentially insanely expensive...

The "gell cell" was the only real option for rechargeables back the, A
"wet" battery is not a safe solution on a bicycle. I don't like them
on a motorcycle either.

On 10/8/2014 3:33 PM, Clive George wrote:

snip

Of course now people have a helmet mounted LED and battery which is
almost smaller than the lamp alone, let alone the lumping great battery
pack one had strapped to one's waist. More light, for longer. And
potentially insanely expensive...

There were SLA bicycle lighting systems as well.

On 10/8/2014 6:01 PM, James wrote:
On 09/10/14 08:10, Sir Ridesalot wrote:

I remember getting a Sanyo roller dynamo and light kit back in the
1980s. That light had the strangest pattern I ever saw and was
useless. It was a very long 'T' with a very narrow beam to a narrow
cross piece at tthe top of tthat 'T'. The cross beam at the head of
the 'T' wasn't long enough to see much. Pity because the drag from
the dynamo was very low and engagement against the tire was far
superior to that of the sidewall bottle dynamo by Union that I'd
tried before. That's what got me to move to battery lights. I used
the Union dynamo supplied headlight but with either a Halogen or
Krypton bulb and powered with a 6 volts battery.


Same. The Sanyo headlight beam shape was ****. Probably enough to be
seen, but not enough to see the road well at all.

Agreed. Same dynamo, same experience with optics. On the advice of a
LBS owner-friend, I switched to a Union halogen lamp, and it was
tremendously better.

What I didn't like about the Sanyo was that it produced far less power
at very low speed (like walking speed) than the Soubitez roller dynamos
I have on some bikes. I still have the Sanyo, but it lives in a drawer.

--
- Frank Krygowski

excellent !

notice 'bearing notch' at spin's end.

While a 'normal' non electric hub has notch, the dyna hub has NOTCH....

guess where the wtts are there ?

SMS states a human horsepower figure as 1/10th HP or do I read wrong there ? I had read 1/50th HP.

Is Frank of Ohio generating sarcasm ? whaddya mean...doesn't matter ?

one foot per mile...

'gnaw its .5 mile out of energy at a 50 mile ride.

the underlying criticism is additive or worser loss of energy forward and loss of contact patch/additive in peddling against front wheel contact as opposed to floating in countersteer....or are you blinded to these facts ?

The racer's edge is lost.

expect a tire from Conti....NACHT FAHRER

On 09/10/2014 01:06, Frank Krygowski wrote:
On 10/8/2014 6:01 PM, James wrote:
On 09/10/14 08:10, Sir Ridesalot wrote:

I remember getting a Sanyo roller dynamo and light kit back in the
1980s. That light had the strangest pattern I ever saw and was
useless. It was a very long 'T' with a very narrow beam to a narrow
cross piece at tthe top of tthat 'T'. The cross beam at the head of
the 'T' wasn't long enough to see much. Pity because the drag from
the dynamo was very low and engagement against the tire was far
superior to that of the sidewall bottle dynamo by Union that I'd
tried before. That's what got me to move to battery lights. I used
the Union dynamo supplied headlight but with either a Halogen or
Krypton bulb and powered with a 6 volts battery.


Same. The Sanyo headlight beam shape was ****. Probably enough to be
seen, but not enough to see the road well at all.

Agreed. Same dynamo, same experience with optics. On the advice of a
LBS owner-friend, I switched to a Union halogen lamp, and it was
tremendously better.

The Union lamps, even the cheap ones, were pretty good for halogens. I
was very disappointed by the B+M lumotec.

On Wed, 08 Oct 2014 09:44:25 -0700, sms wrote:

I find it difficult to believe that an extra 35-50W load on the
alternator would cause a measurable difference in fuel economy which is
advertised in whole numbers, but GM felt that it could. I guess if
you're at 34.499 MPG versus 34.501 MPG you have to round up or down
accordingly, and they were not taking any chances that they'd run into
that unlikely scenario. The claim was that their could be a 0.25 MPG
difference due to the DRLs.


A gallon (the little kind) of petrol has about 120 MJ. Taking motor
efficiency at 25%, and alternator at 75%, and the load as 50W, that works
out to about 12 hours of DRL operation. How long is the test, and what's
the average rate of fuel consumption?

On Thursday, October 9, 2014 12:39:04 AM UTC+1, sms wrote:
On 10/8/2014 3:33 PM, Clive George wrote:



snip



Of course now people have a helmet mounted LED and battery which is

almost smaller than the lamp alone, let alone the lumping great battery

pack one had strapped to one's waist. More light, for longer. And

potentially insanely expensive...



There were SLA bicycle lighting systems as well.

H-E-A-V-Y

Andre Jute

On 09/10/14 20:57, Andre Jute wrote:
On Thursday, October 9, 2014 12:39:04 AM UTC+1, sms wrote:
On 10/8/2014 3:33 PM, Clive George wrote:



snip



Of course now people have a helmet mounted LED and battery which is

almost smaller than the lamp alone, let alone the lumping great battery

pack one had strapped to one's waist. More light, for longer. And

potentially insanely expensive...



There were SLA bicycle lighting systems as well.

H-E-A-V-Y


And fragile. I had one. The battery literally broke apart inside. It
rattled when I shook it.

--
JS

On 10/9/2014 2:27 PM, James wrote:

And fragile. I had one. The battery literally broke apart inside. It
rattled when I shook it.

The one's I built (1980's) used an SLA battery inside a plastic
enclosure that sat on the rear rack and was secured with cinching
straps. The battery was cushioned so it was not subjected to much
impact. Quality Yuasa SLA batteries don't break apart inside.

SLA batteries are heavy, but they did have some advantages over NiCad
and NiMH batteries. You could use ONE battery without unreliable battery
holders or solder-tab batteries. You could choose how much battery you
needed since SLA batteries are available in a wide variety of
capacities. Chargers were readily available and inexpensive.

On top of the enclosure was a xenon strobe. On the front there was a 14W
sealed beam. There was an option for a 35W front light as well but that
was very heavy. The 14W sealed beam was all plastic and very light. It
attached to a reflector bracket. Later there were 25W sealed beams
available but I never used them.

These were systems for commuters, not racers. There were very few
options for good lights back then.

These are the lights, that I have not sold for more than 30 years, that
our resident troll keeps insisting that I am still selling! It was a
money-losing proposition if I counted the assembly time so I stopped. I
also sent out hundreds of packets with the plans, for $3, to anyone that
wanted to build their own, after California Bicyclist published
something about the system.

On Thursday, October 9, 2014 5:46:38 PM UTC-4, sms wrote:
On 10/9/2014 2:27 PM, James wrote:



And fragile. I had one. The battery literally broke apart inside. It

rattled when I shook it.



The one's I built (1980's) used an SLA battery inside a plastic

enclosure that sat on the rear rack and was secured with cinching

straps. The battery was cushioned so it was not subjected to much

impact. Quality Yuasa SLA batteries don't break apart inside.



SLA batteries are heavy, but they did have some advantages over NiCad

and NiMH batteries. You could use ONE battery without unreliable battery

holders or solder-tab batteries. You could choose how much battery you

needed since SLA batteries are available in a wide variety of

capacities. Chargers were readily available and inexpensive.



On top of the enclosure was a xenon strobe. On the front there was a 14W

sealed beam. There was an option for a 35W front light as well but that

was very heavy. The 14W sealed beam was all plastic and very light. It

attached to a reflector bracket. Later there were 25W sealed beams

available but I never used them.



These were systems for commuters, not racers. There were very few

options for good lights back then.



These are the lights, that I have not sold for more than 30 years, that

our resident troll keeps insisting that I am still selling! It was a

money-losing proposition if I counted the assembly time so I stopped. I

also sent out hundreds of packets with the plans, for $3, to anyone that

wanted to build their own, after California Bicyclist published

something about the system.



we needa a vest kit......