Lezyne Deca Drive 1500XXL Report

jbeattie wrote:
On Saturday, March 4, 2017 at 9:36:54 AM UTC-8, Frank Krygowski wrote:
On 3/4/2017 11:25 AM, jbeattie wrote:
On Saturday, March 4, 2017 at 7:38:57 AM UTC-8, wrote:
On Friday, March 3, 2017 at 8:41:26 PM UTC-8, Joy Beeson wrote:
On Thu, 2 Mar 2017 16:14:17 -0800, sms
wrote:

It's unlikely that there's anyone else that has not ridden along a road
with low hanging branches.

I've ridden along many a road with low-lying branches, and once I had
to stop and lift my bike over a low-lying tree -- but I've never seen
a low *hanging* branch over a roadway.

Except maybe right after the derecho, when Park Avenue was full of
brush, but since there were wires tangled all through the mess, I
didn't get close enough to see whether any of the branches were
hanging.

--
joy beeson at comcast dot net
http://wlweather.net/PAGEJOY/
The above message is a Usenet post.
I don't recall having given anyone permission to use it on a Web site.

I'm tall and locally they stopped trimming trees so that my helmet got
caught in the overhanging branches and nearly pulled me off the bike.
One of the guys in the group called road maintenance and the next time
down this hill the branches were trimmed 3 feet higher.

I periodically whack tree branches, too. After the recent snow storms,
there were lots of tree branches hanging into the roadways. It was a
real problem. Now the problem is residual blow-down and gravel -- which
won't get swept for months.

I'm astonished. What's the "period" on "periodically" whacking tree
branches? How badly have you been hurt by these "whacks"? Where on the
road are you riding when that happens? What do the SUV drivers and
truck drivers do when they come to these tree branches? Do you know
cyclists who have been injured by these tree branch whacks? Is there no
agency that keeps the streets clear of such hazards? Why would people
not demand that?

I'm astonished because I live in an area that gets _far_ more snow than
you do. Our club has (at least) weekly rides through a forested
metropolitan park, which gets far less truck traffic than any ordinary
street. Yet I may duck thin twigs with wet leaves perhaps once per
year, but probably far less than that; and if I didn't duck, there would
be no consequences.

I've never come across "low overhanging branches" listed as a riding
hazard in any of the dozens of cycling books I own, nor in any of the
three or four cycling classes I've taken, nor in the curriculum guides
for the courses I taught, nor in any online instructional articles I'm
aware of.

I'm not saying it's impossible to come across a branch so low as to
constitute a hazard; but I think it's got to be about as rare as, say,
dodging a turtle crossing the road. Or in Portland, dodging a salmon
crossing the road.

I believe everyone outside this discussion group considers this a
negligible issue. Why is this group different??

I ducked twice today (bike lane) and had to take the lane on HWY 30 to
get around a giant Laurel that had basically slid or grown across the
bike lane. In a rain storm. It was hailing before the rain. This is a
little piece of my commute, and depending on the year and season, you can
do a lot of ducking. https://www.youtube.com/watch?v=LuIEtk7nvAY

-- Jay Beattie


Seems familiar. Also shows how all the cars stay to the left of the lane.
I forget who was telling me that I was wrong when I said a bike lane keeps
them out of my way because cars keep to the left.

Oh oh. Another thread deviation?

--
duane

On 2017-03-04 12:36, sms wrote:
On 3/4/2017 11:44 AM, Joerg wrote:

snip

If I wanted more than 1000 lumens I'd simply use two or more of these or
I'd buy a light that has several LEDs spread sufficiently apart from
each other.

It is also beneficial not to run LEDs at their abs max datasheet limit
the whole time. Per datasheet the XM-L can take 10W but on my bikes they
never get more than 75%.

On some lights the single LED gets so hot that it unsolders itself from
the board.


That would be a seriously flawed design.


The newer lights are going to multiple LEDs as they improve performance
beyond what is possible with a single LED. Even the dynamo lights are
taking this approach now.


Though dynamo lights are generally wimpy, around 3W. That wouldn't pass
muster for many of my rides.


... Three seems to be the sweet spot for separate
LEDs. There are also the LED arrays with multiple emitters on a single
substrate (often a 3 x 3 array). This works since there is more area for
the thermal solution to connect too, and it may simplify the optics
since it's closer to a point source.


As long as they remain at a healthy temperature and the thermal
protection is gradual instead of a simple cut-out. Point source isn't
required if the lens is adequate.

--
Regards, Joerg

http://www.analogconsultants.com/

On 3/4/2017 1:51 PM, wrote:
On Saturday, March 4, 2017 at 11:09:39 AM UTC-8, sms wrote:
On 3/4/2017 7:38 AM, wrote:

snip

I'm tall and locally they stopped trimming trees so that my helmet got caught in the overhanging branches and nearly pulled me off the bike. One of the guys in the group called road maintenance and the next time down this hill the branches were trimmed 3 feet higher.

Yeah, in a lot of cities, you have to call to get these things taken
care of, they don't have the resources to drive around looking for
cycling hazards.

Ditto for illegal bicycle lane parking. They are probably tired of me
calling this in all the time, but they always respond. Even before I was
on the City Council they were very good about enforcement, but only if
someone called to complain.

I find that most people that are parked in the bicycle lane are temporary and I don't bother with them.

The problem I see most often is delivery trucks. And they are parked
there at the peak time when students are riding down that road to
school. It's more dangerous to have cyclists veering out of the bike
lane into traffic than staying in the traffic lane all the time.

Don't treat the entire road as if you owned it.

Are you insane? Cyclists should treat a marked bike lane as if they own
it, other than when vehicles can legally enter it. That's the whole
point of the bike lane.

And you'll discover that the cars are more polite to you.

On 3/4/2017 1:53 PM, wrote:
On Saturday, March 4, 2017 at 11:18:13 AM UTC-8, sms wrote:
On 3/4/2017 10:09 AM, Sir Ridesalot wrote:
On Saturday, March 4, 2017 at 12:36:54 PM UTC-5, Frank Krygowski wrote:
snipped a lot about lowhanging branches
I believe everyone outside this discussion group considers this a
negligible issue. Why is this group different??

--
- Frank Krygowski

Maybe it's because in OUR areas it is a thing we encounter frequently. The problem with you Frank is if you don't personally see something then in your mind it simply can not exist.

That's been going on in r.b.t. for as long as anyone can remember. "Well
I have never encountered X therefore no one else has ever encountered X
either." "I use X piece of equipment so it's the best choice for
everyone else no matter what."

I'm amazed that a simple post about my experience with a battery powered
light has digressed into a very long rehash of the old dynamo versus
battery debate. Like Jay, and others, I use both kinds of lights at the
appropriate times. Each has their pros and cons. Most of us can discuss
the equipment we choose to use without insisting that everyone else
should be using what we use, without making up silly stories about panel
trucks knocking down tree branches.

My hardy recommendation for steel bikes over carbon fiber is from long experience and near death experiences.

And everyone agrees that carbon fiber frames have much higher risk of
catastrophic failure and should not be used for more than a few years
before being replaced.

On 3/4/2017 2:27 PM, Joerg wrote:

As long as they remain at a healthy temperature and the thermal
protection is gradual instead of a simple cut-out. Point source isn't
required if the lens is adequate.

That is true. But lenses are often not adequate. A lot of people don't
realize the importance of proper optics in lights.

On 05/03/17 04:36, Frank Krygowski wrote:


I'm astonished. What's the "period" on "periodically" whacking tree
branches? How badly have you been hurt by these "whacks"? Where on the
road are you riding when that happens? What do the SUV drivers and
truck drivers do when they come to these tree branches? Do you know
cyclists who have been injured by these tree branch whacks? Is there no
agency that keeps the streets clear of such hazards? Why would people
not demand that?


While I was living in Brisbane, I used a section of road where there is
a painted on bike lane and young planted trees that overhang the bike
lane at times. They may have been trimmed, but a year ago I would move
just outside the bike lane to avoid branches.

/data=!3m6!1e1!3m4!1sM4L3bVhiqbK8iGQCb9-7xg!2e0!7i13312!8i6656!6m1!1e1

No injuries or other mishaps to report.

--
JS

On Thu, 2 Mar 2017 22:53:35 -0800 (PST), Barry Beams
wrote:

So gross total lumens is the unit, instead of Beam Lumens
and Field Lumens, which much better represent a light's usable
visibility. Beam lumens rejects all rays less than 10% of
the brightest. Field lumens rejects all rays less than 50%
of the brightest.

Yep:
http://www.schorsch.com/en/kbase/glossary/beam-angle.html
So, how does one measure field and beam lumens? Methinks I can guess
how it's done[1], but I can't seem to find any references or industry
standards that define the procedure. Any clues or links? In the not
so distant past, I would measure lumens using an integrating sphe
https://www.google.com/search?q=integrating+sphere&tbm=isch
Insert the headlight (or flashlight), obtain an output reading in lux
or footcandles, compensate for reflectivity, grind the numbers, and
you get lumens. However, I don't see any way to eliminate or ignore
light levels (lux) less than 50% or 10% of maximum. The integrating
sphere combines all the light emitted from the light source. It
doesn't matter if the beam pattern is hemispherical as in a light
bulb, narrow as in a flashlight, reflected from a reflector, or
refracted with a lens. Lumens have always been a measure of *ALL* the
light being produced. So, how are field and beam lumens measured?

Field lumens is the best type of lumen measurement to use for bicycle
headlights. Beam Lumens still allows for an excessively bright spot,
but cuts out much of the stray rays that go out as glare.

At the risk of resurrecting the discussion on peripheral illumination
of overhanging branches and obstacles to the side, I beg to differ
somewhat. Certainly, an extremely hot spot is not desirable, mostly
because the iris adjusts to this high light level, at the expense of
peripheral illumination. When I ride with such a light, everything to
the sides go black even though the headlight does deliver some light
in those areas. When the hot spot is less extreme, the iris is not
closed, and I'm able to see some things to the side. If the beam is
uniform and wide angle ( 90 deg), I kill batteries because much of
the power goes into lighting up the roadway to the side instead of
directly ahead. I'm not sure which is best. My biggest lighting
headache is when I make a turn, if the light does not spray some
lumens to the side, I can only see where the bicycle is pointed, not
into the turn or what was previously directly ahead.

A Might Rider 1800, for instance, might only measure 800 Field
lumens and 500 beam lumens at most. The Oculus' even beam will
measure most likely at least 70% of its total lumens Beam lumens
and 90% as field lumens. The reason is how even the beam is,
without a bight center spot. so the max brightness is very
little brighter than most of the rest of the beam.

I tried an experiment using multiple small flashlights to produce a
somewhat uniform beam, rather than single beam modified with a
reflector or lens. I had seven lights. One 2 watt LED directly
ahead, two 0.5 watt were also ahead, and two 0.5 watt on each side to
provide side illumination. I liked it. Sorry, no photos or test data
available.

Also the standard makers want the light to be waterproof at 1
meter depth of water, even though we don't bicycle underwater.

Don't knock it until you've tried it. (I haven't tried it).
https://en.wikipedia.org/wiki/Underwater_cycling
https://www.google.com/search?q=underwater+cycling&tbm=isch

An IP6 level like I and many others use, allows for anything
a bicyclist might encounter in the rain, without harm or
loss of function to the light.

IP6 is dust tight and requires a vacuum chamber to test.
https://en.wikipedia.org/wiki/IP_Code
My guess(tm) is you want IP64 or better.

Incidentally, I've run various pieces of electronics through IP67
testing. Things that get warm have a unique problem passing such
tests. If you turn on your light, and warm it up, it will cool down
rather rapidly when sprayed with water or immersed in water (at 22C).
The air inside the light will produce a partial vacuum, which will
literally suck the water past most seals and gaskets.

See what Brian Bowling of Planet Ultra wrote in his review
about his ride with an Oculus in the rain. But at a much
lower cost to manufacture.

https://www.facebook.com/PlanetUltraCycling/posts/10158182570745360:0
Ok, I read it, but didn't find anything of interest. What I look for
are test results, measurements, comparisons, expectations, and
numbers, none of which I found.


[1] I posted the procedure in r.b.t. about 2 years ago, but now I
can't seem to find it again. I'll keep looking or maybe throw
together a web page. Note that ANSI IT7.215 is not applicable as it's
specific to film and slide projectors.

--
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 3/4/2017 5:13 PM, James wrote:

snip

While I was living in Brisbane, I used a section of road where there is
a painted on bike lane and young planted trees that overhang the bike
lane at times. They may have been trimmed, but a year ago I would move
just outside the bike lane to avoid branches.

The issue is more about at night, when you can't see low hanging
branches unless you have a light with proper optics that has sufficient
spill. No one, well almost no one, thinks that anyone is talking about
trying to light up the sky with a 1500 lumen light, it's just about
using common sense and realizing that there's a valid reason why you
need some sideways and upward spill.

On 3/4/2017 5:15 PM, Jeff Liebermann wrote:
On Thu, 2 Mar 2017 22:53:35 -0800 (PST), Barry Beams
wrote:

So gross total lumens is the unit, instead of Beam Lumens
and Field Lumens, which much better represent a light's usable
visibility. Beam lumens rejects all rays less than 10% of
the brightest. Field lumens rejects all rays less than 50%
of the brightest.

Yep:
http://www.schorsch.com/en/kbase/glossary/beam-angle.html
So, how does one measure field and beam lumens? Methinks I can guess
how it's done[1], but I can't seem to find any references or industry
standards that define the procedure. Any clues or links? In the not
so distant past, I would measure lumens using an integrating sphe
https://www.google.com/search?q=integrating+sphere&tbm=isch
Insert the headlight (or flashlight), obtain an output reading in lux
or footcandles, compensate for reflectivity, grind the numbers, and
you get lumens. However, I don't see any way to eliminate or ignore
light levels (lux) less than 50% or 10% of maximum. The integrating
sphere combines all the light emitted from the light source. It
doesn't matter if the beam pattern is hemispherical as in a light
bulb, narrow as in a flashlight, reflected from a reflector, or
refracted with a lens. Lumens have always been a measure of *ALL* the
light being produced. So, how are field and beam lumens measured?

Field lumens is the best type of lumen measurement to use for bicycle
headlights. Beam Lumens still allows for an excessively bright spot,
but cuts out much of the stray rays that go out as glare.

At the risk of resurrecting the discussion on peripheral illumination
of overhanging branches and obstacles to the side, I beg to differ
somewhat. Certainly, an extremely hot spot is not desirable, mostly
because the iris adjusts to this high light level, at the expense of
peripheral illumination. When I ride with such a light, everything to
the sides go black even though the headlight does deliver some light
in those areas. When the hot spot is less extreme, the iris is not
closed, and I'm able to see some things to the side. If the beam is
uniform and wide angle ( 90 deg), I kill batteries because much of
the power goes into lighting up the roadway to the side instead of
directly ahead. I'm not sure which is best. My biggest lighting
headache is when I make a turn, if the light does not spray some
lumens to the side, I can only see where the bicycle is pointed, not
into the turn or what was previously directly ahead.

There's a new light with a mount that automatically rotates the light
based on the way you are looking. It has a wireless transmitter that you
mount on your helmet.

But you may be over-thinking this. Yes, with a light that delivers some
light to the sides, and upwards, you may not always need that side and
upwards spill, but it'd be hard to design a system that only had that
spill when you were turning are looking for street signs or branches. A
slightly larger rechargeable battery and continuous side and upward
spill is fine. Proper optics would limit the intensity of the spill so
you didn't blind oncoming traffic.

On Thu, 2 Mar 2017 22:53:35 -0800 (PST), Barry Beams
wrote:

Beam lumens rejects all rays less than 10% of the brightest.
Field lumens rejects all rays less than 50% of the brightest.
Field lumens is the best type of lumen measurement to use for
bicycle headlights. Beam Lumens still allows for an excessively
bright spot, but cuts out much of the stray rays that go out
as glare.

You might find this helpful:
http://802.11junk.com/jeffl/pics/bicycles/Front-Light-False-Color/index.html
It's my attempt to take a photograph of the beam pattern as projected
on the roadway, and convert the various light levels to pseudo-colors.
I should be able to use the same method to highlight the 10% and 50%
boundaries. I used the program ImageJ to make these:
https://imagej.nih.gov/ij/
The headlight photos came from Peter White Cycles:
http://www.peterwhitecycles.com/headlights.php
One problem is that I forgot how I did the pseudo-color conversion.
Ah, foundit:
https://groups.google.com/forum/#!msg/rec.bicycles.tech/zskyvYS746s/Eljh0IVjZokJ

Convert to gray scale.
Image - Color - Channels Tool
Set it for Grayscale, which should also set it for only Channel 1.

Convert to false color:
Image - Lookup Tables
Pick an LUT (look up table). I suggest either 16 colors or BRGBCMYW.

Diversion: When measuring headlight lumens, I suspect one projects
the headlight beam against a white wall that's perpendicular to the
beam. That makes measurements fairly easy. However, when one
actually uses the headlight, it's projected against the roadway, which
is almost parallel to the beam, and certainly not perpendicular. If a
uniform beam is deemed to be desirable, then the light should be
brighter at the top of the beam, and dimmer at the bottom. Just a
thought.

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