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  #71  
Old March 10th 17, 06:22 AM posted to rec.bicycles.tech
Sir Ridesalot
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On Friday, March 10, 2017 at 1:12:14 AM UTC-5, James wrote:
On 10/03/17 17:02, Sir Ridesalot wrote:


Bummer that your law is so specific.

Where I am in Ontario, Canada it can get in the 90s F and have a
humidity index of 90 - 100% at times. That's hard on the system
because you sweat a LOT but it doesn't evaporate but can run down
into your eyes where it can burn as if it's an acid.

Cheers


We regularly get summertime temperatures over 100F here, and can be that
humid as well.

Good for rapid dehydration, hallucination, etc..

--
JS


Saw a guy one year on the organized ride here. After 100 kms he was at the ride end and was in agony from severe cramping. Ended up in ER and last I hear was he'd had 4 IV bags pumped into him. I've heard from professional medical personnel that severe cramping can actually pull ligaments or tendons away from the bones or muscles. Yopu really do not want to get that dehydrated.

Cheers
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  #72  
Old March 10th 17, 01:05 PM posted to rec.bicycles.tech
Duane[_3_]
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Posts: 1,900
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On 10/03/2017 12:55 AM, James wrote:
On 09/03/17 00:35, Duane wrote:
On 07/03/2017 7:09 PM, James wrote:
snip
Now that you mention it...

I don't like putting sun screen on the top of my head because in the
heat and humidity I sweat a lot and it tends to run down into my eyes
and stings most painfully with sun screen mixed in.

So my foam hat has big ventilation holes that let the sun light through
to my scalp.

If I was allowed to ride without a foam hat I could keep the sun off my
scalp with a cloth cap, but that's not an option in this country.

If I develop a skin cancer on the top of my head, I shall seek to sue
the government, for their law makes adequate sun protection with
sufficient ventilation near on impossible.


When it's too hot to ride with my cycling cap under my helmet, I use one
of these:
https://www.mec.ca/en/product/5046-050/Summer-Skullcap

Probably a better idea than skin cancer.



How hot does it get where you are?


Here in Quebec 32-34C. Not that bad as it isn't constant and not that
humid. In New Orleans where I'm from, ~38 - 40C is not unusual. And
always humid.

I imagine it's hotter where you are but some of these UPF materials work
pretty well. Light and cool. Not as spiffy as my cycling caps though.



  #73  
Old March 10th 17, 07:45 PM posted to rec.bicycles.tech
JBeattie
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Posts: 3,214
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On Monday, March 6, 2017 at 1:33:10 PM UTC-8, Joerg wrote:
On 2017-03-06 10:47, wrote:
On Sunday, March 5, 2017 at 5:26:18 PM UTC-8, Jeff Liebermann wrote:
On Sun, 5 Mar 2017 16:03:30 -0800 (PST),

wrote:

Thanks Jeff. These however all appear to be battery powered
lights. We were sort of looking for lights that operated on the
hub dynamo of 6V 3W or the Globe dynamo of 12V 6W or four times
the power.

Sorry, I thought you were still open to looking at battery powered
lights. Here's what I fished out of my bookmark dumpster. No
reviews and few tests, but some interesting dynamo graphs and
numbers: http://www.myra-simon.com/bike/dynotest.html
http://pilom.com/BicycleElectronics/DynamoCircuits.htm
http://www.eeweb.com/blog/extreme_circuits/power-mosfet-bridge-rectifier



This one is well worth reading (or skimming) and has quite a few test
results:
http://swhs.home.xs4all.nl/fiets/tests/verlichting/index_en.html

This is why the hub generator has so little drag.

Well, let's do some arithmetic. If your dynamo is rated at 3
watts, and your lighting is rated at 70 lumens/watt, then the most
you can perhaps deliver is 210 lumens. 6 watts will get perhaps
420 lumens. Usually, it's less as the losses accumulate.
Rectification losses, optical losses, heat degradation, and
connector losses all conspire to produce lower output.

You might find it useful to know how bright you want your light.
For that, you'll need a Lux meter. I have a Lutron LX-102 which
works nicely, and two junk meters I bought on eBay for sanity
checks: http://www.ebay.com/sch/i.html?_nkw=lux+meter Get one
that has a wide range. Lowest on mine is 1000 lux, and highest
range is 50,000 lux.

Find a dark night and an accomplice to operate the meter and send
them down the road to the farthest distance that you might want to
illuminate with your headlight. Use a headlight or flashlight to
light up that area. Have your accompli's take a reading. It will
probably be zero. Now, cut the distance in half and take a
measurement. It will be 2x as bright (lux) at half the distance or
4x as bright at 1/4th the distance. Adjust the brightness for what
it would have been if the light meter was sufficiently sensitive.

Converting the brightness (lux) to luminous flux (lumens) requires
that you know the distance to the accomplice, and the illumination
angle. (1 lux = 1 lumen/square-meter)

The form below makes a mess of bad assumptions but is good enough
for a rough approximation:
https://www.ledrise.com/shop_content.php?coID=19 Once you know
how many lumens you think you need, and have adjusted for overly
ambitious expectations, you can determine which lighting technology
is suitable.

Lets say you want to see 8 meters ahead and 20 degrees to each
side (or 40 degree conical beamwidth) at 20 lux, which is rather
dim. Plugging into the web page above, I get 485 lumens needed.
You won't be able to do that with a 3w dynamo, but might squeeze by
with a 6w and an oval shaped beam.


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


As a very occasional night rider I am interested in battery powered
lights but I think that I was attempting to give a thought to a
commuter that would use his light a great deal.


I use my lights a great deal because they are on during the day as well
except on segregated bike paths.

Recharging is 2nd nature to me. Bike gets parked back in the garage,
li'l round connector gets plugged in, done. Sometimes I deliberately do
not charge past 8V until shortly before a ride. That improves battery
lifetime.

The real McCoy would be a worryfree system like in a car where it
recharges while riding. If I ever switch the road bike front wheel to
one with a hub dynamo I will do that. Right now it only has a bottle
dynamo, too much drag and it eats the left side wall of "modern" tires.
Power output of those is well above 3W at higher speeds if you provide
the proper electronics. I could go into that but it's nerdy tech stuff.
Essentially you need what is called a SEPIC or at least a buck converter
plus some sort of maximum power point tracking (MPPT) control for that
converter. Sounds more complicated than it really is but do not expect
the bicycle industry to deliver anything even remotely close anytime soon..

Realistically you could eke out 4-6W depending on you speed. That's not
enough to feed a MagicShine clone which wants 8W on high plus a watt or
so for the rear lights. And maybe another 1-2W for the MP3 player. Plus
the smart phone. And the electric razor :-)

In my case this would work nicely because I need the full 10W total only
on county roads and in city areas where car drivers tend to misbehave.
Else it drops to a net load of 4-5W or even much lower. So the dynamo
would recharge the watt-hours you used up on the county road. Once the
battery gets full it throttles back. Just like in car.


I notice that a large number of the people in our group have flashing
red rear lights and it isn't long before these batteries run down
enough that the taillight even blinking is almost entirely
unnoticeable. So I don't have much respect for battery power for a
great deal of use.


Yep, that's a major nuisance. However ... one can power these lights off
a regular 8.4V Li-Ion battery or even a dynamo (after rectification) by
providing a 3V regulator. Small enough to fit where the two AAA cells
used to be.

If battery rear lights at least had a low-battery warning. Technically
that would be a piece of cake. But no ... nothing :-(

If you're riding a lot during the day with a DRL then you really should consider a dyno light. I was riding with my son this morning, and we passed a guy with a DRL, and I thought that it was unnecessarily bright for a DRL -- and goddamn if it wasn't a round-beam Supernova E3. The two of us were DRL-less, although I was personally in need of recharging.

-- Jay Beattie.
  #74  
Old March 10th 17, 10:54 PM posted to rec.bicycles.tech
Jeff Liebermann
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Posts: 2,826
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On Wed, 8 Mar 2017 09:34:49 -0800, sms
wrote:

On 3/6/2017 7:41 PM, Jeff Liebermann wrote:

I couldn't find any test reports or method used on the Supernova site.
I did find this test of the M99 model:
http://supernova-lights.com/en/blog/supernova-blog-1/post/first-test-performance-supernova-m99-pro-br-36
1100 lumens / 16 watts = 68.7 lumens/watt. Hmmm...


No need to use the most expensive LEDs on a battery powered light.


Yes, but they only deliver 68.7 lumens/watt instead of the spec sheet
claim of 200 lumens/watt. As I explained in my previous rant,
reflector loss, lens loss, electronics losses, power source ESR loss,
and temperature derrating, are the culprits. In other words, don't
expect to get spec sheet efficiencies from the finished product.



--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #75  
Old March 10th 17, 11:19 PM posted to rec.bicycles.tech
Jeff Liebermann
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Posts: 2,826
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On Wed, 8 Mar 2017 09:45:43 -0800, sms
wrote:

On 3/6/2017 9:22 AM, Jeff Liebermann wrote:

Kinda looks like all of them will sorta deliver 2.5 watts before the
core saturates (to provide some level of voltage regulation). Further
down the page is a "Low Speed Power" graph, which shows that most can
produce 2.0-2.5 watts at 10km/hr. One could assume that the dynamo
will deliver 4.0 watts, but that would require buying one of the few
better (hub) dynamos listed, and riding at 25-30km/hr (15-19mph).

If I were designing or sizing a lighting system suitable for my slow
style of "cruising", I would use the worst case 10km/hr (6mph) and 2.0
watt figures.


You've touched on one of the reasons why dynamo lights haven't caught on
in the U.S..


Touched? I was trying to sledge hammer the reason. Basically, one
design is not going to make everyone happy. Some riders can easily
maintain the speeds necessary to utilize the dynamo at well above it's
rated capacity. Others, like me, can barely make it spin.

I'll spare you my rant on the benefits of a hybrid battery + dynamo
system.

I wish that it were possible for inexpensive, dynamo powered lights to
provide adequate illumination for commuting, but it isn't. I recognize
that few people can afford nearly $500 for a hub dynamo wheel and a
SuperNova E3 Triple 2. For commuting, where there is no problem
charging batteries every night, a high power LED set-up is more
economical and provides better illumination. It's hard enough getting
people to spend even $25 on a bicycle light, getting them fork out $500
for a dynamo wheel and a decent dynamo light would be damn near impossible.


So how duz it cost to build one dynamo wheel and headlight?
Prices are my guess(tm) based on experience and random googling.

Shimano Nexus series hubs can be found for about $70.
Wheelsmith spokes are about $0.50/ea or 26 for $18.
Generic rim for $35.
Tire, tube, and rim tape for $20.
B&M Lumotec LUXOS B for $64.
Wiring for free.
====================================
total = $207

While $207 is not cheap, it's much less than your $500 estimate.


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #76  
Old March 10th 17, 11:30 PM posted to rec.bicycles.tech
Jeff Liebermann
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Posts: 2,826
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On Wed, 8 Mar 2017 09:39:28 -0800, sms
wrote:

On 3/6/2017 6:27 PM, Jeff Liebermann wrote:


http://www.ebay.com/itm/142066277090
$0.97 gets you a two AAA batteries packaged inside a flasher


You used to be able to get 2xAA powered flashers, but they weren't 97


I haven't seen any with AA batteries in many years. All the cheap
ones seems to AAA.

The trend now is toward smaller, USB rechargeable tail lights. No reason
you could not charge these via a dynamo.


Yep. That would make it a hybrid battery + dynamo system, which is
what methinks might be the best compromise. However, it won't work
for megalumen headlights because the dynamo charger will not deliver
enough power to fully recharge the large battery required to run high
power lighting.

Among the cheap tail lights a
https://www.amazon.com/Solar-Powered-Bike-Tail-Light/dp/B006FC6CJA
$2.78.

However, I couldn't find any really cheap Li-Ion rechargeable tail
lights. The best I could do is:
http://www.ebay.com/itm/USB-Rechargeable-White-Red-Bicycle-Tail-Light-Waterproof-6Modes-COB-led-Tailight-/401141418710
for $8.50.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #77  
Old March 10th 17, 11:30 PM posted to rec.bicycles.tech
AMuzi
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Posts: 9,553
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On 3/10/2017 5:19 PM, Jeff Liebermann wrote:
On Wed, 8 Mar 2017 09:45:43 -0800, sms
wrote:

On 3/6/2017 9:22 AM, Jeff Liebermann wrote:

Kinda looks like all of them will sorta deliver 2.5 watts before the
core saturates (to provide some level of voltage regulation). Further
down the page is a "Low Speed Power" graph, which shows that most can
produce 2.0-2.5 watts at 10km/hr. One could assume that the dynamo
will deliver 4.0 watts, but that would require buying one of the few
better (hub) dynamos listed, and riding at 25-30km/hr (15-19mph).

If I were designing or sizing a lighting system suitable for my slow
style of "cruising", I would use the worst case 10km/hr (6mph) and 2.0
watt figures.


You've touched on one of the reasons why dynamo lights haven't caught on
in the U.S..


Touched? I was trying to sledge hammer the reason. Basically, one
design is not going to make everyone happy. Some riders can easily
maintain the speeds necessary to utilize the dynamo at well above it's
rated capacity. Others, like me, can barely make it spin.

I'll spare you my rant on the benefits of a hybrid battery + dynamo
system.

I wish that it were possible for inexpensive, dynamo powered lights to
provide adequate illumination for commuting, but it isn't. I recognize
that few people can afford nearly $500 for a hub dynamo wheel and a
SuperNova E3 Triple 2. For commuting, where there is no problem
charging batteries every night, a high power LED set-up is more
economical and provides better illumination. It's hard enough getting
people to spend even $25 on a bicycle light, getting them fork out $500
for a dynamo wheel and a decent dynamo light would be damn near impossible.


So how duz it cost to build one dynamo wheel and headlight?
Prices are my guess(tm) based on experience and random googling.

Shimano Nexus series hubs can be found for about $70.
Wheelsmith spokes are about $0.50/ea or 26 for $18.
Generic rim for $35.
Tire, tube, and rim tape for $20.
B&M Lumotec LUXOS B for $64.
Wiring for free.
====================================
total = $207

While $207 is not cheap, it's much less than your $500 estimate.



Low price but no actual German electrons. You call that a
fashion statement?

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


  #78  
Old March 10th 17, 11:34 PM posted to rec.bicycles.tech
SMS
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Posts: 8,281
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On 3/10/2017 3:19 PM, Jeff Liebermann wrote:
On Wed, 8 Mar 2017 09:45:43 -0800, sms
wrote:

On 3/6/2017 9:22 AM, Jeff Liebermann wrote:

Kinda looks like all of them will sorta deliver 2.5 watts before the
core saturates (to provide some level of voltage regulation). Further
down the page is a "Low Speed Power" graph, which shows that most can
produce 2.0-2.5 watts at 10km/hr. One could assume that the dynamo
will deliver 4.0 watts, but that would require buying one of the few
better (hub) dynamos listed, and riding at 25-30km/hr (15-19mph).

If I were designing or sizing a lighting system suitable for my slow
style of "cruising", I would use the worst case 10km/hr (6mph) and 2.0
watt figures.


You've touched on one of the reasons why dynamo lights haven't caught on
in the U.S..


Touched? I was trying to sledge hammer the reason. Basically, one
design is not going to make everyone happy. Some riders can easily
maintain the speeds necessary to utilize the dynamo at well above it's
rated capacity. Others, like me, can barely make it spin.

I'll spare you my rant on the benefits of a hybrid battery + dynamo
system.

I wish that it were possible for inexpensive, dynamo powered lights to
provide adequate illumination for commuting, but it isn't. I recognize
that few people can afford nearly $500 for a hub dynamo wheel and a
SuperNova E3 Triple 2. For commuting, where there is no problem
charging batteries every night, a high power LED set-up is more
economical and provides better illumination. It's hard enough getting
people to spend even $25 on a bicycle light, getting them fork out $500
for a dynamo wheel and a decent dynamo light would be damn near impossible.


So how duz it cost to build one dynamo wheel and headlight?
Prices are my guess(tm) based on experience and random googling.

Shimano Nexus series hubs can be found for about $70.
Wheelsmith spokes are about $0.50/ea or 26 for $18.
Generic rim for $35.
Tire, tube, and rim tape for $20.
B&M Lumotec LUXOS B for $64.
Wiring for free.
====================================
total = $207

While $207 is not cheap, it's much less than your $500 estimate.


Yes, I was looking at buying everything pre-made from a vendor like
Peter White. A product, not a project.

You can certainly buy a hub, spokes, and rim and assemble it yourself.

You can even buy a good LED lamp for about $20, though without a standlight.

You can buy dynamo wheels on e-Bay (generally NOS) for $100 or so, i.e.
http://www.ebay.com/itm/282367087029 or
http://www.ebay.com/itm/282316745203 plus shipping in some cases.

  #79  
Old March 10th 17, 11:41 PM posted to rec.bicycles.tech
James[_8_]
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Posts: 5,739
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On 11/03/17 00:05, Duane wrote:
On 10/03/2017 12:55 AM, James wrote:
On 09/03/17 00:35, Duane wrote:
On 07/03/2017 7:09 PM, James wrote:
snip
Now that you mention it...

I don't like putting sun screen on the top of my head because in the
heat and humidity I sweat a lot and it tends to run down into my eyes
and stings most painfully with sun screen mixed in.

So my foam hat has big ventilation holes that let the sun light through
to my scalp.

If I was allowed to ride without a foam hat I could keep the sun off my
scalp with a cloth cap, but that's not an option in this country.

If I develop a skin cancer on the top of my head, I shall seek to sue
the government, for their law makes adequate sun protection with
sufficient ventilation near on impossible.


When it's too hot to ride with my cycling cap under my helmet, I use one
of these:
https://www.mec.ca/en/product/5046-050/Summer-Skullcap

Probably a better idea than skin cancer.



How hot does it get where you are?


Here in Quebec 32-34C. Not that bad as it isn't constant and not that
humid. In New Orleans where I'm from, ~38 - 40C is not unusual. And
always humid.

I imagine it's hotter where you are but some of these UPF materials work
pretty well. Light and cool. Not as spiffy as my cycling caps though.




Thanks. I might look in to it.

Cheers.

--
JS
  #80  
Old March 11th 17, 12:07 AM posted to rec.bicycles.tech
Jeff Liebermann
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Posts: 2,826
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On Fri, 10 Mar 2017 17:30:57 -0600, AMuzi wrote:

So how duz it cost to build one dynamo wheel and headlight?
Prices are my guess(tm) based on experience and random googling.

Shimano Nexus series hubs can be found for about $70.
Wheelsmith spokes are about $0.50/ea or 26 for $18.


Typo. That should be 36 spokes for $18.

Generic rim for $35.
Tire, tube, and rim tape for $20.
B&M Lumotec LUXOS B for $64.
Wiring for free.
====================================
total = $207

While $207 is not cheap, it's much less than your $500 estimate.


Low price but no actual German electrons. You call that a
fashion statement?


Well, Japanese and German electrons should be compatible. However,
the cost of the SON hub needed to produce genuine German electrons is
well over $200. That brings the cost of the wheel to $337. The
prices I picked out of thin air are the cheapest that I could find new
from vendors that sell component parts. I specifically did not use
Banggood and AliExpress to avoid counterfeits and junk. Modifying an
existing front wheel would save $55 for the rim, tire, and tube. Even
running on Japanese electrons, it's still a rather expensive solution
compared to a battery powered headlight and goes a long way to explain
why battery powered lights are more common.

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




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