SFPD needs to crack down on Bicyclists with No Lights (& SF-GG Bridge-LarkspurRide Report)

wrote in message
...

Besides, riding on anything other than carbon fiber is also a hazard.

In another three months I should be fully recovered from riding on carbon
fiber. My accident was last June.

"SMS" wrote in message
...

There are still ample opportunities to not conform. Alas, the price of
non-conformity is often a lot higher now than in the past.

You mean that steel bikes are more expensive now?

I owned an SUV before the term SUV was even coined (an old Toyota Land
Cruiser). I had to sell it once everyone had an SUV, or I would be accused
of being a conformist.

Why would anyone own a vehicle designed to look macho? That alone means that
you ain't.

In rec.bicycles.misc SMS wrote:
The lights I find most annoying are those flashing LED bicycle
lights and HID bicycle headlights. OTOH, the former does make the
cyclist visible to motor vehicles in the daytime which is their
goal,

A flashing LED in bright daylight? Good one 8)


I have a dynamo light on the bike I was riding in San Francisco on
Saturday night, and it was just a complete waste of perfectly good
human power to use it.

You could install a reasonable one if it wasn't against your deepest
believe 8)

--
MfG/Best regards
helmut springer panta rhei

Helmut Springer wrote:
In rec.bicycles.misc SMS wrote:
The lights I find most annoying are those flashing LED bicycle
lights and HID bicycle headlights. OTOH, the former does make the
cyclist visible to motor vehicles in the daytime which is their
goal,

A flashing LED in bright daylight? Good one 8)

Obviously you've never seen one of the Cree 3W LED flashing lights. They
are extremely bright and visible in the daytime.

You could install a reasonable one if it wasn't against your deepest
believe 8)

I've seen people with the so-called "decent" ones. They are not much
better than the Union/Marwi. There is one supposedly really good one
from SolidLights (it's gotten good reviews from dynamo light users) but
it's like $300 just for the lamp.

"Helmut Springer" wrote in message
...
In rec.bicycles.misc SMS wrote:
I have a dynamo light on the bike I was riding in San Francisco on
Saturday night, and it was just a complete waste of perfectly good
human power to use it.

You could install a reasonable one if it wasn't against your deepest
believe 8)

I have never seen a European type under-the-bottom-bracket generator being
sold here Helmut.

The kind available here are the side-of-the-tire kind that are very
inefficient and scrub a lot.

And of course the in-hub generators are the best of all. But none that I've
seen generate sufficient power for a decent headlight that is effective at
anything other than a dim glow that is supposed to alert drivers not to run
you over.

I wonder if you could couple the hub generator with an LED headlight and get
a decent illumination for riding at, say, 25 kph on an unlit roadway.

Tom Kunich cyclintom@yahoo. com wrote:
I have never seen a European type under-the-bottom-bracket
generator being sold here Helmut.

Those have decreased quite a lot here by now...in-hub generators
have pretty much taken over that market segment.


I wonder if you could couple the hub generator with an LED
headlight and get a decent illumination for riding at, say, 25 kph
on an unlit roadway.

IMO yes: at that speed you can easily power 2 or 3 headlights with
3W LED if you wanted. With recent models like Schmidt's Edelux or
B&M's Cyo Sport it has become easier, and technology robably won't
stop there.

http://nabendynamo.de/produkte/ar_tabelle.html shows some pictures
of modern LED headlights on the German market, powered by a hub
generator ot 20km/h.

--
MfG/Best regards
helmut springer panta rhei

Helmut Springer wrote:
Tom Kunich cyclintom@yahoo. com wrote:
I have never seen a European type under-the-bottom-bracket
generator being sold here Helmut.

Those have decreased quite a lot here by now...in-hub generators
have pretty much taken over that market segment.

Can you even buy the bottom bracket dynamos anymore? I have an old Sanyo
that still works, but I haven't seen that type for sale anywhere in the
world for a long time.

IMO yes: at that speed you can easily power 2 or 3 headlights with
3W LED if you wanted. With recent models like Schmidt's Edelux or
B&M's Cyo Sport it has become easier, and technology robably won't
stop there.

I doubt if you could three 3W LED headlights with a 3W dynamo. Two might
be do-able at high speeds. These LED headlights waste a lot of power as
heat, as well as wasting some in the drive circuitry and regulation
circuitry.

"Efficiency and LED lifetime mainly depend on its cooling. This is why
we placed the LED on a massive copper heat sink, which in turn conducts
the heat to the aluminum housing, and then to the outside air. At high
speed the good cooling allows for an increase of 20% luminous flux
compared to usual LED headligts, some of which can reach more than 100°
Celsius (210° F)."

Of course the other issue with the Edelux is that not many people are
going to spending $212 on just a headlight.

SMS wrote:
Can you even buy the bottom bracket dynamos anymore?

Yes.


I doubt if you could three 3W LED headlights with a 3W dynamo.

Several people in d.r.f do, as the hub generator isn't limited to 3W
at sufficient speed. But Andreas has explained that at length in
r.b.t.


--
MfG/Best regards
helmut springer panta rhei

Phil W Lee wrote:


You haven't seen any modern ones then.
I wonder if you could couple the hub generator with an LED headlight and get
a decent illumination for riding at, say, 25 kph on an unlit roadway.

Easily, and I can't think of any reason to do anything else.
When you are providing the power, you don't want to waste it on
inefficient lighting technologies like bits of hot wire.
LEDs give the best bang for your buck, with better lumen/watt than
even HID.

HID are far more efficient in lumens/watt.

But yes, there's no hot wire on LEDs, instead there's a very hot
semiconductor junction, with all the cooling challenges of
semiconductors. There is even active cooling available for LED lamps
now, because passive convection cooling can't keep up. Alas, nothing is
free. It was interesting to read the literature on the Edelux,
especially the part about the cooling.

Still, a 3W hub generator could sufficiently power a single 3W LED
headlight at moderate speed. Now all that needs to happen is for some
company in China to come out with such a headlight for $20, and it'll
enable a new generation of bicycle dynamo lighting. Certainly $212 LED
headlights aren't going to have a huge market.

The problem is that LED headlights aren't just an LED in place of a
filament bulb. The LED headlights require a switching regulator, you
can't drive them directly from the dynamo. The Edelux literature
mentions "very low loss" in their switching regulator but they aren't
more specific than that. The firt thing they must be doing is running
the output of the dynamo through a full wave bridge rectifier, which has
a maximum efficiency (with perfect diodes that don't exist) of 81.2%.
Then they're running the output through a DC-DC switching regulator,
which also has losses. By the time they're done. they probably only have
70% of the power remaining.

C.H. Luu wrote:
This is one of the nicest ride you can do in the north bay. I usually
head into the Marin headlans beforing going through Sausalito and then
onto Larkspur.

Yes, Conzelman road is just wonderful, except when the park rangers
decide to give speeding tickets to cyclists on the one-way downhill
section. Riding through the tunnel is also fun, though now that it's
legal to go through it's less exciting than when the military police
would wait at the east end for bicyclists to ticket.

The stretch of road between Tiburon and Larkspur is
especially scenic and has little traffic. Granted it's our right to
travel the roads, but it is rather dangerous at night.

I don't know where you get the idea that riding at night, with good
lighting, is any more dangerous that riding during the daytime. That
stretch is pretty narrow with no shoulder, and I tend to take the whole
lane a lot so if the vehicles want to go by they really have to pass,
not just squeeze me off the road. The Flash Flag helps a lot as well.

With good lights on a bicycle you really stand out at night, especially
on unlit roads. In the daytime is when you are less visible, though now
I see more and more cyclists with "DRLs" consisting of very bright LED
flashing headlights and taillights that are visible even in the daytime.

When you curse bicyclists while driving at night is when you almost hit
them because they have no lights, or the lights they have are so poor
that they aren't visible even with lights. It's just insane that these
people value their life so little that they're not spending $40 or so
for some good lights.

I honestly don't think that this will get any better.

But it has gotten much better already. Bicycle lighting has evolved from
the days of lights that neither made a cyclist visible, nor lit up the
road well enough to ride at an expeditious rate.

travel during daylight hours. If you must brave the darkness, be
prepared to put your foot down at a moment's notice. I've ridden
betweent the Pier area and the Presidio. Even in daylight, it's
hazardous.

Between the single's Safeway (the pick-up spot for singles in the Marina
district) all the way to Fort Point it's a wide paved multi-use trail
with separate lanes for each direction of bicycles and pedestrians. Once
you enter the Presidio the traffic is very light and you don't even need
to use the trail if you don't want to.

Due to the fog, you really want to be using good lights even on full
moon nights.

I found it interesting that the biggest bicycle rental company down by
the wharf, Blazing Saddles, has a selling point of "Blazing Saddles
provide sic a 24 hour drop off area, so you can experience ultimate
fun, all day long, no time constraints!" That's great, especially with
the prices they charge for daily rentals, of $28-105 per day, since you
want to get your money's worth. But they really should provide equipment
that makes such riding legal.