Archive for category Recumbent Bicycling

Monthly Science: Bicycling!

Mary finished out the National Bike Challenge with a rank of 3353 of 47 k riders, which, by my reckoning, is wonderfully good. She’s #1 in the Poughkeepsie area (admittedly, of only eight riders), with the second-place rider at 90% of her point score.

She did it by riding on her usual missions, along our usual routes, around the usual obstacles:

NYS Rt 376 at Westview Terrace

NYS Rt 376 at Westview Terrace

Her bike odometer recently rolled past 20 k miles; at least one battery change stole a pile o’ miles from her total, so the bike has accumlated more than that.

As the song goes, my gal is red hot… in the best way!

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If You Can Get To BNC, You Can Get To Anything

That’s what Mad Phil taught me, back in the day, and it’s still true:

15 W Dummy Load - Stacked Adapters

15 W Dummy Load – Stacked Adapters

From the top:

  • 15 W dummy load with N female
  • N male to BNC female
  • BNC male to UHF female
  • UHF male to UHF male
  • UHF female on homebrew antenna mount

Obviously, I don’t have enough adapters: I need one with N male to UHF male.

I actually spent money to get from the reverse-polarity SMA connector on the Wouxun radios directly to UHF female, matching the cable to the antenna mount in one step.

Sometimes an unsteady ziggurat of adapters isn’t appropriate.

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Tour Easy: Arkel RT-40 Underseat Packs vs. HT Mount

I just replaced the rather old and tattered Easy Reacher underseat packs on my Tour Easy ‘bent with shiny new Arkel RT-40 packs:

Arkel RT-40 bag on Tour Easy - front view

Arkel RT-40 bag on Tour Easy – front view

The retina-burn white reflective tag under the black hand strap is actually a foreshortened view of the Arkel logo.

They’re longer and taller than the old packs, which isn’t entirely a Good Thing: the inside bag gently kisses the pavement during steeply banked high speed turns. The main compartment is slightly narrower, so I bent the license plates (which used to fit neatly on the bottom) to form a hard floor with a low lip on the inside edge. That, in combination with tightening the pack’s internal strap, prevents the foam-core bottom panel from drooping; maybe the edge won’t hit the pavement quite so often.

They also ride much higher on the racks. To install the packs, I had to unbolt the seat to raise it upward, slide the packs underneath, twiddle the clamps onto the rack rods, then reinstall the seat. Those puppies are not getting loose without tools and a struggle!

Because they’re longer, the right pack collided with the HT mount behind the seat:

Arkel RT-40 bag vs HT holder

Arkel RT-40 bag vs HT holder

So I moved the mount up to the middle crossbar:

Arkel RT-40 bag - relocated HT holder

Arkel RT-40 bag – relocated HT holder

I’m not entirely happy with that arrangement, as the holder sits snug against the rear packs. So far, I rarely need those in addition to the RT-40s, as each underseat bag can swallow an upright gallon milk jug or two Butternut squashes in addition to all the other stuff I normally carry.

The array of reflective patches and piping and pull tabs probably makes me look (more) like a low-flying UFO at night, but that’s fine with me: the more it resembles a UFO, the less hassle I get.

 

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Extracting Video Frames and Overlaying Text

The avconv incantation required to put text on frames extracted from a video file looks like this (it’s all on one line, so you’ll need some side scrolling action):

avconv -ss 00:11:47 -i /mnt/backup/Video/2014-09-08/MAH00070.MP4 -t 1 -f image2 -q 1 -vf "drawtext=fontfile=/usr/share/fonts/truetype/ttf-dejavu/DejaVuSansMono.ttf : text='2014-09-08 10\:58\:47' : fontcolor=white : fontsize=60 : box=1 : boxcolor=black@0.7 : x=1200 : y=30" MAH00070-001147-%03d.jpg

That’s applying some hints to the rather succinct drawtext doc.

The -ss 00:11:47 sets the starting time relative to the beginning of the file, so it’s an offset that, when added to the file start time in the Exif metadata, produces the actual time-of-day. The extracted frames begin at the closest “seek point”, which I presume will be pretty close to the specified second. The -accurate_seek option may be relevant. Verifying all that could be tricky.

The -t 1 specifies the duration. Each second produces 60 frames, numbered from 001 to 060 in the output filename, as defined by the %03d in the output filename format string.

The -vf "drawtext=" gibberish does the actual text overlay, with all the parameters tucked inside the double quotes.

You must escape all colons in the text string (as '10\:58\:47', note the single quotes), because unescaped colons separate the drawtext options.

The fontsize seems to be in pixels with an upper limit of 72.

The boxcolor rectangle just barely covers the characters; there’s no way to enlarge it just a few more pixels to make a nice frame. The fraction at the end of black@0.7 string produces 70% opacity.

I manually added the actual starting time (10:47) to the offset time for each segment (previewed with vlc), jammed that into the avconv command, and extracted some interesting frames from a recent ride…

I get plenty of clearance while approaching an intersection, which is pleasant:

MAH00070-001118-047

MAH00070-001118-047

Absorbed in something on the passenger seat while I’m trackstanding the ‘bent and watching the brake lights:

MAH00070-001139-017

MAH00070-001139-017

The turn signal goes on just after acceleration commences:

MAH00070-001141-017

MAH00070-001141-017

Because I never pass on the right, I didn’t participate in a classic right hook:

MAH00070-001144-050

MAH00070-001144-050

The traffic signal goes yellow as I cross the walk ladder, with the tail of the SUV visible beyond the crosswalk on the right. The green-to-yellow transition takes 10 frames = 1/6 second and this image shows the half-intensity point of both incandescent bulbs:

MAH00070-001147-041

MAH00070-001147-041

The rest of the ride seemed less eventful.

Frankly, that’s way too much handwork for the results in the upper-right corner. I think a better way starts with extracting unannotated frames from the video, then slapping timestamps on them using ImageMagick, calculating and feeding it the appropriate values for each frame.

Putting the annotation up in the sky seems better than near the bottom corners, if only because images of the pavement might actually be useful. The timestamp needs the frame number and I think splitting it into two shorter sections (date and time) in the left and right upper corners might work better.

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Invisible Asterisk: Except Cops

The signs at every Dutchess Rail Trail grade crossing and access point seem unambiguous:

DCRT - No Motor Vehicles

DCRT – No Motor Vehicles

More specific signs appear at random intervals along the trail:

DCRT - All Terrain Vehicles Prohibited

DCRT – All Terrain Vehicles Prohibited

You can’t see it, but every sign includes an invisible asterisk introducing the invisible clause “Except Cops”:

DCRT - Sheriff ATV Convoy

DCRT – Sheriff ATV Convoy

Back when the Dutchess County deputy sheriffs rode huge ATVs that occupied nearly the entire paved trail and bulldozed everybody out of their way, I had the temerity to ask why they weren’t riding bikes. The deputy sheriff told me, rather condescendingly, that they had to be prepared for anything and that there had already been incidents.

These little ATVs aren’t quite so imposing and, more likely, also fit on the new bridges and between the bollards, which may explain everything.

I’ve seen what might be their best use case, although ambulances can attract your attention without an ATV escort:

DCRT - Sheriff ATV Leading Ambulance

DCRT – Sheriff ATV Leading Ambulance

Straight up, I have no objection to police patrols on the rail trail.

do object to the official mindset that simply adds an invisible exception to any inconvenient rule.

As I see it, the root cause of the militarized police and extralegal government activities we’ve seen across the country in recent years boils down to “That law / regulation / rule does not apply to us, because we are the government.”

I can ride the length of the DCRT and back in about two hours, averaging 12 mph, without getting particularly sweaty in the process; the track in that link shows a three hour ride that includes the HVRT and a Walkway scrum, plus the ride from and to home. A police ATV can’t go much faster than that on the trail, even with lights and sirens, because oblivious pedestrians keep getting in the way.

If an officer on a bike can’t keep up with me, then something has gone badly wrong with the job requirements for becoming a deputy sheriff.

As far as “being prepared for anything” goes, the cargo capacity of those little ATVs rules out a bunch of hardware that fit in the big ones: anything seems an elastic concept. A bike can carry enough equipment for many incidents; my tool kit weighs more than some bike frames, the packs have plenty of room to spare, and there’s always the trailer option. I doubt genuine Mil-Spec assault rifles would come in handy on the rail trail.

It’s also not clear why an officer on a bike can’t call for the same backup as an officer on an ATV: those buggies lack fancy VHF antennas, so they’re using a hand-held radio or phone. The 5 W amateur radio on my bike, through a mobile VHF antenna on a crappy ground system, can easily reach local amateur radio repeaters and APRS nodes. Many pedestrians seem absorbed with their phones, so getting microwaves into and out of the trail doesn’t pose much of a problem.

Cops-on-bikes present a much less aggressive aspect than cops-on-ATVs who ignore the rules that apply to the rest of us.

They could do it differently, as the department has both bikes and ATVs.

,

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Eroded PTT Cable

While installing new underseat packs (about which, more later) on my Tour Easy, I discovered a bight of PTT cable had been touching the top of the chain:

Eroded PTT cable - Tour Easy

Eroded PTT cable – Tour Easy

The gentle ripples to the right of the worn-through section seem particularly nice; you couldn’t do that deliberately if you had to.

This section of cable should have been taped to the upper frame bars. It’s hidden under the seat, just in front of the rear fender, and between the under-seat packs, so it’s basically invisible from any angle.

Soooo, that probably explains a bit of the intermittent trouble I’d been having with the PTT switch, although most of it came from the corroded switch contacts.

Rather than replace the whole cable, I cut out the eroded section, spliced the conductors, and taped it firmly back on the tubes.

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Hudson River Eagle Sightings

A pocket camera can’t do justice to the Bald Eagles, just before dusk and halfway across the Hudson River from our river cruise yacht:

Bald Eagles at dusk - Hudson River near Hudson NY

Bald Eagles at dusk – Hudson River near Hudson NY

We got a closer look at the pair of eagles who once graced the original Grand Central Station and are now standing guard at St Basil Academy in Garrison.

This one glanced away from the entrance, perhaps to keep an eye on us:

Eagle at St Basils Academy - entrance

Eagle at St Basils Academy – entrance

Another watches over an interior road:

Eagle at St Basils Academy - cliff

Eagle at St Basils Academy – cliff

They’re two tons of cast iron apiece and, should any of you want a restoration project, I’m sure the good folks at St Basil’s could work something out.

We saw those during the Cycling the Hudson Valley tour: riding during the day, camping and touristing in the evening.

Several years ago we encountered a Penn Station eagle at the Washington Zoo:

Karen on Penn Station eagle

Karen on Penn Station eagle

Fly away, young Valkyrie, fly away …

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