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  #51  
Old March 8th 17, 04:03 AM posted to rec.bicycles.tech
Sir Ridesalot
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On Tuesday, March 7, 2017 at 7:09:21 PM UTC-5, James wrote:
Snipped
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.

--
JS


Just curious, does the legislation specifically state that your helmet must be worn on your head? Or does it simply state that a helmet must be worn? On a long ride a few years ago it got extremely hot so I slung mu helmet over my shoulder on a long srtrap. the organizers at a rest stop saw it and said i must wear the helmet on my head. I showed them the waiver and also showed them that it only stated that I promised to wear a helmet but there was no mention of wear I had to wear the helmet. Perhaps your local legislation has a similar loophole?

Cheers
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  #52  
Old March 8th 17, 04:50 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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On 3/7/2017 10:03 PM, Sir Ridesalot wrote:
On Tuesday, March 7, 2017 at 7:09:21 PM UTC-5, James wrote:
Snipped
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.

--
JS


Just curious, does the legislation specifically state that your helmet must be worn on your head? Or does it simply state that a helmet must be worn? On a long ride a few years ago it got extremely hot so I slung mu helmet over my shoulder on a long srtrap. the organizers at a rest stop saw it and said i must wear the helmet on my head. I showed them the waiver and also showed them that it only stated that I promised to wear a helmet but there was no mention of wear I had to wear the helmet. Perhaps your local legislation has a similar loophole?


Years ago, a friend and I drove support for a charity ride. The ride
was not organized by our club, but our club volunteered to help out.

Anyway, the ride had a "helmets required" policy. Late in the day, we
came upon a guy, probably in his 60s, riding along with a rider number,
but with his helmet strapped to his bike's back rack. He probably took
it off because of the heat.

My friend said "We've got to stop him and make him put his helmet on!"

I said "How? Will we tell him he's not allowed to ride on this public
road? Let him alone; he's old enough to know what he's doing." And I
refused to slow or stop the car I was driving.

BTW, that was so long ago, I still sort of believed in helmets back then.

--
- Frank Krygowski
  #53  
Old March 8th 17, 09:34 AM posted to rec.bicycles.tech
John B.[_3_]
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On Wed, 8 Mar 2017 11:09:16 +1100, James
wrote:

On 07/03/17 06:15, jbeattie wrote:
On Sunday, March 5, 2017 at 9:57:44 PM UTC-8, James wrote:
On 06/03/17 10:22, Barry Beams wrote:


Burn time: What if you had five or ten hours battery time at your
generator's brightness? My Oculus gives at least that much
brightness, and a quickly field replaceable battery so you can put in
a fresh battery. Other rechargeables leave you out of light and out
of luck when the battery drains. Oculus also comes with a spare
battery included.


What if I don't want to play with batteries?


Then you're done with the battery light discussion and may move on to helmets.


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.


Such a problem. You could use a "do rag", as they call it in America;
or a Balaclava hood such as we have here, made of very stretchy fabric
and can be worn as a skull cap or pulled down to shield the face and
neck both worn under the helmet of course.
See: http://tinyurl.com/hquplny

And apparently a new innovation I see the ladies wearing this year. A
sort of poke bonnet with at least a six inch deep brim. Again, of
course, worn under the helmet and not only covering he crown of the
head but keeps the face white also :-)

Or perhaps that ultimate in protection for the Cyclist who is ultra
worried about sun protection::
http://tinyurl.com/zf8uexq
--
Cheers,

John B.

  #54  
Old March 8th 17, 02:35 PM posted to rec.bicycles.tech
Duane[_3_]
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Posts: 1,900
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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.
  #55  
Old March 8th 17, 03:22 PM posted to rec.bicycles.tech
JBeattie
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On Tuesday, March 7, 2017 at 6:15:05 PM UTC-8, Frank Krygowski wrote:
On 3/6/2017 2:12 AM, DATAKOLL MARINE RESEARCH wrote:
Assumptions or measured ?


I forgot to respond to that question.

I've measured dynamo torque vs. speed. As James says, the resistance
torque of a dyno decreases as speed increases. It doesn't decrease as
much as speed increases, however, so the power required still increases
with speed.

Example: Soubitez roller dynamo

Speed (mph) 6 12 18 24
Torque (N*mm) 26.4 22.6 18.1 14.3 with 12 Ohm load
Torque (N*mm) 22.6 23.4 19.6 15.1 with 24 Ohm load

I found similar behavior with other dynamos.

With an open circuit, drive torque did increase with road speed.


Why would torque increase with speed with an open circuit?

-- Jay Beattie.
  #56  
Old March 8th 17, 03:38 PM posted to rec.bicycles.tech
[email protected]
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On Monday, March 6, 2017 at 1:04:03 PM UTC-8, Doug Landau wrote:
What if I don't want to play with batteries?

Then you're done with the battery light discussion and may move on to helmets.


or carbon frames versus steel frames.



Stainless!!!
http://gearpatrol.com/2017/01/26/bes...l-bike-makers/


Can't do it. These people who are riding old rusty 6 speeds are telling me that carbon fiber is as safe as steel.
  #57  
Old March 8th 17, 03:40 PM posted to rec.bicycles.tech
JBeattie
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Posts: 5,870
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On Monday, March 6, 2017 at 11:58:20 PM UTC-8, wrote:
On Tuesday, March 7, 2017 at 5:11:29 AM UTC+1, Frank Krygowski wrote:
On 3/6/2017 9:37 PM, sms wrote:

This light http://supernova-lights.com/en/supernova-e3-triple-2 claims
640 lumens at 4.5W. 4.5W is definitely possible from a nominal 3W
dynamo. It claims 800 lumens peak.

Note that his light, while sold in Germany, is not "road legal."
because, according to reviews, it doesn't suffer the problems of StVZO
lights, "It has a very broad light output that is closer to a floodlight
than a focused beam, and so doesn’t give the ‘tunnel’ effect of some of
the powerful battery-powered lights. This means it’s great for
illuminating branches and hazards above you and off to the side." As we
all know, the problem with StVZO legal lights are related to the
extremely focused spot beam.


Here's an example of an StVZO headlamp (2013 model) with the "extremely
focused spot beam" the Scharf complains about.
http://peterwhitecycles.com/images/p...lux-II-800.jpg

See that tiny spot? ;-)


--
- Frank Krygowski


That is the headlight I use and it looks exactly the same on a pitch dark street. So again I don't understand why people find this amount of light insufficient.


I clearly have a defective hub or light or something -- or else I need a pitch dark forest road with reflective gravel.

I couldn't see a godamn thing riding home last night -- again in a rain storm, with a death grip on the bars because I was getting blown over. Wet pavement swallows light, but the real problem is all the point-source light pollution -- blinding car headlights when riding in wrong-side bike facilities. I actually yelled at some guy on a bike with a mega-flasher. Pop, pop, pop go the retinas. WTF? How could anyone possibly think that was O.K.? This was in a wrong-side two-way bike facility, so I'm staring into car lights on the left and bike lights on the right. Maybe I should get some of those polarized night-driving glasses.

-- Jay Beattie.

  #58  
Old March 8th 17, 04:02 PM posted to rec.bicycles.tech
Duane[_3_]
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Posts: 1,900
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On 08/03/2017 9:40 AM, jbeattie wrote:
On Monday, March 6, 2017 at 11:58:20 PM UTC-8, wrote:
On Tuesday, March 7, 2017 at 5:11:29 AM UTC+1, Frank Krygowski wrote:
On 3/6/2017 9:37 PM, sms wrote:

This light http://supernova-lights.com/en/supernova-e3-triple-2 claims
640 lumens at 4.5W. 4.5W is definitely possible from a nominal 3W
dynamo. It claims 800 lumens peak.

Note that his light, while sold in Germany, is not "road legal."
because, according to reviews, it doesn't suffer the problems of StVZO
lights, "It has a very broad light output that is closer to a floodlight
than a focused beam, and so doesn’t give the ‘tunnel’ effect of some of
the powerful battery-powered lights. This means it’s great for
illuminating branches and hazards above you and off to the side." As we
all know, the problem with StVZO legal lights are related to the
extremely focused spot beam.

Here's an example of an StVZO headlamp (2013 model) with the "extremely
focused spot beam" the Scharf complains about.
http://peterwhitecycles.com/images/p...lux-II-800.jpg

See that tiny spot? ;-)


--
- Frank Krygowski


That is the headlight I use and it looks exactly the same on a pitch dark street. So again I don't understand why people find this amount of light insufficient.


I clearly have a defective hub or light or something -- or else I need a pitch dark forest road with reflective gravel.

I couldn't see a godamn thing riding home last night -- again in a rain storm, with a death grip on the bars because I was getting blown over. Wet pavement swallows light, but the real problem is all the point-source light pollution -- blinding car headlights when riding in wrong-side bike facilities. I actually yelled at some guy on a bike with a mega-flasher. Pop, pop, pop go the retinas. WTF? How could anyone possibly think that was O.K.? This was in a wrong-side two-way bike facility, so I'm staring into car lights on the left and bike lights on the right. Maybe I should get some of those polarized night-driving glasses.



I hear your pain. I can't take these guys with they're freaking search
beams on their bikes. Why is it not ok for cars to come up to you on a
road with their high beams on but it's ok for a cyclist to blind
everyone looking at them? And WTF is the point of high intensity (what
you call mega) flashers at night? I've had near crashes due to both of
these types of idiots.

  #59  
Old March 8th 17, 04:57 PM posted to rec.bicycles.tech
Sir Ridesalot
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Posts: 5,270
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On Wednesday, March 8, 2017 at 9:40:57 AM UTC-5, jbeattie wrote:
On Monday, March 6, 2017 at 11:58:20 PM UTC-8, wrote:
On Tuesday, March 7, 2017 at 5:11:29 AM UTC+1, Frank Krygowski wrote:
On 3/6/2017 9:37 PM, sms wrote:

This light http://supernova-lights.com/en/supernova-e3-triple-2 claims
640 lumens at 4.5W. 4.5W is definitely possible from a nominal 3W
dynamo. It claims 800 lumens peak.

Note that his light, while sold in Germany, is not "road legal."
because, according to reviews, it doesn't suffer the problems of StVZO
lights, "It has a very broad light output that is closer to a floodlight
than a focused beam, and so doesn’t give the ‘tunnel’ effect of some of
the powerful battery-powered lights. This means it’s great for
illuminating branches and hazards above you and off to the side." As we
all know, the problem with StVZO legal lights are related to the
extremely focused spot beam.

Here's an example of an StVZO headlamp (2013 model) with the "extremely
focused spot beam" the Scharf complains about.
http://peterwhitecycles.com/images/p...lux-II-800.jpg

See that tiny spot? ;-)


--
- Frank Krygowski


That is the headlight I use and it looks exactly the same on a pitch dark street. So again I don't understand why people find this amount of light insufficient.


I clearly have a defective hub or light or something -- or else I need a pitch dark forest road with reflective gravel.

I couldn't see a godamn thing riding home last night -- again in a rain storm, with a death grip on the bars because I was getting blown over. Wet pavement swallows light, but the real problem is all the point-source light pollution -- blinding car headlights when riding in wrong-side bike facilities. I actually yelled at some guy on a bike with a mega-flasher. Pop, pop, pop go the retinas. WTF? How could anyone possibly think that was O.K.? This was in a wrong-side two-way bike facility, so I'm staring into car lights on the left and bike lights on the right. Maybe I should get some of those polarized night-driving glasses.

-- Jay Beattie.


What you need are flip up/flip down sunglass lenses to wear over glasses or clear cycling goggles. They do help a lot. I'd also like to be able to mount heat seeking missiles so that I could blow those blinding lights up. However I do realize that'd be illegal. Like I've mentioned before, there are times when i have to slam on my brakes becasue some idiot with super bright lights steady or strobe blinds me to the pointI can not see where the road or trail is and a stop is warranted lest I ride off either.

Hmmm, I wonder if a good size flip up polycarbonate mirror on the front of my bike could/would reflect tht annoyingly dangerous over bright light back atthe rider using it? Letthem know what it's like to be blinded at night.

Cheers
  #60  
Old March 8th 17, 06:10 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
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On 3/8/2017 9:22 AM, jbeattie wrote:
On Tuesday, March 7, 2017 at 6:15:05 PM UTC-8, Frank Krygowski wrote:
On 3/6/2017 2:12 AM, DATAKOLL MARINE RESEARCH wrote:
Assumptions or measured ?


I forgot to respond to that question.

I've measured dynamo torque vs. speed. As James says, the resistance
torque of a dyno decreases as speed increases. It doesn't decrease as
much as speed increases, however, so the power required still increases
with speed.

Example: Soubitez roller dynamo

Speed (mph) 6 12 18 24
Torque (N*mm) 26.4 22.6 18.1 14.3 with 12 Ohm load
Torque (N*mm) 22.6 23.4 19.6 15.1 with 24 Ohm load

I found similar behavior with other dynamos.

With an open circuit, drive torque did increase with road speed.


Why would torque increase with speed with an open circuit?


I think because losses are inevitable. In addition to bearing drag,
there's a certain amount of loss due to eddy currents in the dynamo's
components, and there's windage loss churning the air around inside the
thing. Bottle dynamos spin at surprisingly high speed, BTW. 5000 rpm
would not be unusual.

--
- Frank Krygowski
 




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