
---------------------- 
NOTES FROM THE BIKELAB 
Issue #9 -- 4/21/91
by Steven K. Roberts
----------------------

Copyright (C) 1991 by Steven K. Roberts.  All Rights Reserved.
(Intact reposting and free distribution is OK with permission; 
personal forwarding is OK without.)

	IN THIS ISSUE:
		Late Night Maunderings
		Chaos and the Pedaling Emulator
		Bike tech
		General Progress Report
		Another Midnight Attack

	Soft chains are the most difficult to break:
	affection, ease.
	The spirit, wide-eyed, limp-muscled, nestles
	   on its side
	and waits....
				-- graffiti on SF Muni bus

	3:15 AM.  It's becoming a familiar time -- a favorite one,
	even.  This time of day, there are few commercials on the radio
	to disrupt the back-to-back jams.  There are no phone calls,
	few stray beeps from the Sparc, none of that constant
	temptation to invoke Aladdin to check GEnie or browse America
	Online.  The time is mine; the only hint of other life is the
	occasional passage of a sleepy guard making the rounds or the
	clatter of a night janitor emptying trash.  (They must
	wonder... passing my locked door in the middle of the night,
	hearing cranked music of every genre, the growl/whirr/whine of
	Cecil/Makita/Dremel followed by the roar of the Great Sucking
	Monster whisking deadly aluminum chips from equipment bays...
	what's that guy DO in there?  He never leaves!)

	Occasionally I do leave, of course.  Silicon Valley by day is a
	frenetic zoo, a place of angry traffic, clutter, stress, and
	crowds.  Sometimes I have no choice:  I drag my entire body
	around the city just to acquire a $6.00 part, a process of
	dubious efficiency.  But by night, it's a different world out
	there... quiet and laid-back.  I do my food shopping,
	gassing-up, and wallet-refilling after midnight, skulking
	through the darkness with the graveyard shift, breezing through
	intersections that would have me grumbling by day, strolling
	across El Camino while hearing only silence.

	Tonight there are no errands.  I've been extending the power
	bus from the trailer, through the hitch, into a small RUMP
	sub-panel, and up to a distribution area in the main RUMP bay.
	It's now only one more hop to the console, and then things will
	start to flicker to life.  Perhaps that's why I'm working late
	-- this is an exciting epoch in the creation of a system (much
	more so than the endless acquisition and repackaging of
	isolated components, marathon list-editing, and timeless
	staring into space as vaporous n-dimensional images of BEHEMOTH
	evolve in the wetware CAD system -- virtual revision levels
	incrementing furiously as a massive hierarchical file structure
	becomes at once reassuringly structured and hopelessly
	intimidating).

	The only thing that makes this entire project tolerable is the
	fact that it's a PROJECT, not a job.  That ethic began in grade
	school, when I noticed the vast behavioral gulf between science
	fair projects and homework.  The latter was irrelevant noise,
	busy work involving neither invention nor creativity.  Why
	bother?  The same tasks had already been done thousands of
	times by others, and would doubtless be repeated more or less
	identically by thousands more.  They obviously didn't need ME
	to go through it all again.  But science fairs!  Every year,
	the pressure would build relentlessly as I slaved in my
	basement lab building acoustic speech synthesizers, pre-CCD
	speech compressors, servo-linked harmonographs, diode-matrix-
	based Morse code translators... whatever outpourings of 60's
	technopassion happened to enchant me at the time.  Each was
	unique, an obsession, lovingly crafted on a tight deadline and
	then documented at the last possible minute (just like in
	industry) -- and those 7 annual marathons had more to do with
	passion and curiosity than fear of tests.

	Those were formative years, so it's no surprise that I've spent
	the last 20 doing everything possible to avoid employment.  It
	has begun to occur to me that this whole bike system -- all 8
	years of it from chrome-moly frame to ethernet, from tire pump
	to satcomm, from sponsor deals to teeth-clenching mountain
	grades -- is just a colossal science fair project, thoroughly
	laced with romance, adventure, and the sweet mad essence of
	life itself...

Chaos and the Pedaling Emulator
-------------------------------

In this issue's emailbag, we have this food for thought from Mike
(obrien@aerospace.aero.org):

	I know that in most Sun farms, the order in which things reboot
	after, say, a power failure can be critical.  If this guy's
	yellow pages aren't up yet, the main file server will get stuck
	listening to that guy over there, who can't boot without the
	right yellow pages, and so forth and so on.  This has to do
	with, I suspect, an as-yet-unexplored offshoot of the science
	of dynamical systems, aka chaos theory (a subject I'm studying
	in some detail 'cause I'm geyser-mad and I want to model geyser
	eruptions with chaos theory).  The point is that when you have
	lots of computers busily interdepending, you can have
	"pseudo-chaotic" operational configurations, which are stable,
	but broken.

	Sooooo...  just wondering, mind you...  are you sure that the
	happily operational configuration of SPARC, PC, Mac, and Forth
	engines is the ONLY possible configuration, and one which will
	be reached every time things come up?  Just a thought.

					-- Mike O'Brien

	Yikes.  A useful warning... thanks!

					-- Steve

The following arrived from dbs@kodak.pa.dec.com... thought you might
enjoy this twist in BEHEMOTH's design contributed by Digital Equipment
Corp:

	As part of a non-competitive joint venture with Sun
	Microsystems and other software and hardware vendors, Digital
	Equipment will contribute a key ingredient to Steven Roberts'
	BikeLab.  Still under development, BEHEMOTH has been
	described as a cornucopia of high tech gadgetry on wheels.  The
	bike is being prepared by Roberts for the summer riding season
	in a lab donated by Sun Microsystems.  Since he will certainly
	be kept busy on his trip attending to hardware and software
	issues, Digital's contribution will allow him to offload the
	effort of propelling his bike onto a pedaling emulator.

	The device involves a mechanical device that emulates the human
	pedaling motion.  The pedal will be driven by a metal arm-like
	device that in turn is powered by a cylinder sliding up and
	down in a tube.  During the power stroke the cylinder will be
	forced down by the explosion of some sort of combustible
	material that must be refilled with each rotation.  Digital
	engineers are confident that Roberts will be able to find
	plentiful supplies of fuel on his trip.

Bike tech
---------

	Oh yes.  That reminds me.  There... IS a bicycle somewhere
	underneath all that stuff, isn't there?  Often I forget that
	and end up with nasty surprises, like trashed bearings and
	stretched chains, startled and betrayed by real-world
	mechanical wear when I'm thinking digitally.  For most of those
	16,000 miles I pedaled around with the same parts I acquired
	back in 1983, some of which were old even then.  Hard-core
	bikies would occasionally sneer at my antique Campy high-flange
	front hub, and I grew quite tired of replacing headsets every
	few hundred miles.

	Well, things are changing.  With 350 pounds (I, um, HOPE that's
	all there is) of cargo, some of the component decisions are
	critical.  With the help of bike wiz Greg Davis, machinists
	Dave Berkstresser and Ron Covell, and the bicycle industry
	itself, I've been re-doing BEHEMOTH from the frame up.  Let's
	take a mechanical tour, starting at the front...

	The front wheel is a 16 x 1-3/8 alloy rim with 36 holes, custom
	made by Weinmann for the Avatar recumbents about 10 years ago.
	The new hub, currently under construction, is a custom
	variable-reluctance motor-generator assembly spinning on SKF
	sealed bearings... more on that when it becomes a reality.  A
	Mathauser single-cylinder hydraulic rim brake is mounted on the
	Ishawata fork crown, and brazed to this crown is a 1/4-20 stud
	that holds a teflon-lined rod end for the steering linkage.
	The headset is a sealed Chris King unit -- the latest and
	hopefully the final iteration in my endless quest for one that
	can take the abuse of heavy equipment.  This headset has a good
	reputation among the hard-core mountain bikers (and I've also
	shock-mounted the new console to filter out high-frequency
	impulse energy).

	Moving back, we come to the crankset.  From 1983 until last
	week, this has been a 185-mm TA tandem crank, with a single
	drive chainring on the left side.  Now it's a custom
	chrome-moly 191-mm crankset made by CQP, with sealed bearings
	installed in the original eccentric that once allowed me to
	adjust for chain-length variations on the tandem-style 1:1
	crossover drive.  Attached to the cranks is a pair of Cycle
	Binding pedals, whose floating heads lock into a very well
	designed shoe system.  Unfortunately, the company went out of
	business before I could hit the road... but the product seems
	to be excellent and I guess I'll find a new vendor when these
	eventually wear out.

	The transmission is perhaps the most striking mechanical
	feature of BEHEMOTH (at least until the landing gear assembly
	is built -- details in a future issue).  It has 105 speeds,
	ranging from a killer granny gear of 7.87 inches to a robust
	tall gear of 122.  This is accomplished via three derailleurs:
	a rear unit hacked on the the port-side crossover drive
	assembly in addition to a more-or-less conventional 21-speed
	indexed system on the starboard side.  The gears are:

	D:  Drive ring on crankset:		24

	X:  5-speed cluster on crossover:	18-26-34-40-46

	F:  Standard front triple:		19-36-44

	R:  7-speed freewheel cluster:		13-15-17-20-24-28-34

	You can think of the gear chart as a 3-D matrix of 5x3x7 cells,
	calculating any ratio as (D/X)*(F/R)*27.  Incidentally, a
	couple of those gears involved a bit of trickery:  the 5-speed
	crossover cluster is built on a modified Shimano crankset (arms
	removed and lathe-turned to point symmetry).  The top three
	rings are on the 110 mm bolt circle with some special spacers,
	and the other two -- aided by a "Quad Tamer" -- are on the 74
	mm circle.  Likewise, the triple had a bit of help -- that
	19-tooth ultra-granny is mounted on a Limbo Spider that allows
	the use of a standard steel cog in place of the usual inner
	chainring.  The spindle that connects them obviously is longer
	than usual -- it's another custom job from Gary Cook at CQP,
	142 mm long.

	Incidentally, I am often asked why so many gears.  A 105-speed
	bike?  Isn't this a bit excessive, in addition to being harder
	to say than "18-speed"?  Not at all -- this not only provides a
	stunning granny gear of less than 8 inches (1.4 mph at a
	cadence of 60 RPM -- now you know why the landing gear), but
	also gives me enough easily addressable ratios to allow a good
	impedance match between body and bike under any load
	conditions.  That's important when the whole mess, body
	included, is well over a quarter ton...

	Derailleur choices are based on construction quality,
	integration with the selected shifters, and availability.  I do
	not yet have any road time with this component suite, so it is
	not meant to be a recommendation.  At the moment, we have a
	Shimano Deore half-step front derailleur, a SunTour XC Pro on
	the rear, and an older SunTour wide-range unit on the crossover
	transfer assembly.  I'm experimenting with the new Grip Shift
	from SRAM for the main two, and a pair of classic SunTour
	Barcons mounted in the forward seat tubes for the crossover and
	the drag brake.  Chains are Sedisport ATB on the left and
	SunTour XC Pro on the right.

	The rear hub is a double-threaded Phil Wood tandem unit, with
	48 holes.  14-gauge DT stainless spokes connect it to the
	Weinmann concave alloy rim in cross-4 symmetrical UNDISHED
	pattern.  I can recommend this highly... my undished 48-spoke
	wheels have taken 16,000 miles of heavy abuse without ever
	breaking a spoke.  The only damage I've ever had with this
	configuration occurred in Whiteville, NC, when a pickup-truck
	door materialized in my path and somehow drove the derailleur
	into the spokes, forming a highly-effective one-shot braking
	device that contributed significantly to the suite of bike and
	body ills that suddenly manifested themseves.  (While
	recovering from back and leg injuries and waiting for parts
	shipments in Whiteville, by the way, I wrote a gripping story
	called "Blood in the Spokes."  It observed, at one point, that
	"I am out spokin' at times...  rolling from a wheel-truing deal
	to true wheeling-dealing, toiling at truth while reeling from
	the raw deal of a rear wheel's real ruin...")

	The trailer wheels are 36-hole Suzue sealed hubs with butted
	stainless spokes to 20" Sun Chinook rims (whatever those are)
	and Haro slick tires.  The bike's rear tire has historically
	been a Specialized 1-3/8 Expedition, which they discontinued
	and then apparently re-introduced (if the lastest Nashbar is
	any guide).  I'm considering others, including the lively
	Michelin Hi-Lites and something Greg is recommending.  The
	front tire is whatever I can get -- not much quality rubber
	exists for 16" wheels.  Kid's sidewalk bike tires from Western
	Auto typically last 1,500 miles, but it would be nice to
	optimize rolling resistance et al with something made for the
	"serious" bike market.

	In the braking department, I have a pair of Mathauser
	hydraulics -- single-cylinder on the front, double on the
	rear.  There has always been either an Araya drum or Phil Wood
	disk on the rear... I'm dissatisfied with both for various
	reasons and am looking into a custom motorcycle-style hydraulic
	to use as a drag brake and wet-weather insurance.  There's also
	the regenerative system under computer control, of course --
	the first line of stopping defense -- and I'm hoping to add a
	pair of brakes to the trailer as well.  The problem is that I
	have only so much grip strength, and ganging brakes on the
	levers actually has a negative effect on stopping power due to
	additive power-transfer losses.  This calls for some other
	energy storage device, which translates into either a surge
	system (tricky design but interesting) or a linkage that
	captures the force imparted to another brake in order to
	actuate the next two down the line.  Later.

	Finally, the frames.  The bike frame is a work of art, a
	supremely reliable and elegant custom job by Jack Trumbull of
	Franklin Frames in Columbus, OH.  The steering geometry is
	perfect, which is to say almost "dead," with no tendency to
	oversteer like so many commercial recumbents.  It has about
	1/2" of positive trail.  Naturally, it's 4130 Cr-Mo.  A thick
	tandem-style heavy-wall bottom tube and triple stays contribute
	to overall stiffness and resistance to overload fracture.

	The trailer frame geometry is defined by the original Equinox
	trailer that formed a template for this unit.  I tossed the
	original upper structure of aluminum and fabric and built the
	cardboard-fiberglass body... then noticed that the original
	frame was now too fragile for the application.  Paul Sadoff of
	Rock Lobster Cycles built a beautiful new one of heavy 4130,
	and now, if I had the strength, I could probably haul Cecil the
	900-pound milling machine without frame failure.  But I won't.
	This obsession with having it all has gone quite far enough!

	Jeez.  No wonder this is all a shock.  Looking back over the
	foregoing, I realize how little attention I've paid to
	bike-tech until recently -- it's easy to treat the bike itself
	as a chassis and focus all attention on the whiz-bang gizmology
	layered atop it.  Problem is, failures of bike components can
	leave me stranded or worse, so this time money is no object and
	I'm depending on help from bike-savvy experts in the business.
	It's starting to show...

General Progress Report
-----------------------

	In other news, the cable harness is now to the point where the
	battery management and raw power distribution span bike and
	trailer.  The only hard part here was dealing with the fact
	that the two units can be disconnected.  With the batteries
	nominally treated as one big unit, unplugging is no problem...
	but what happens if I leave the trailer charging in a sunny
	campsite and go for a ride with the SPARCstation running Frame
	via Ethernet to MacX?  I come back with a low bike battery,
	plug in, and ZAP!  A hundred amps flows for a few milliseconds,
	popping breakers and burning connector pins.  The solution,
	suggested by Glenn Glassner, is elegantly simple:  a monster
	iron-core toroid in the inter-battery bus slows down this
	initial surge enough to contain it within the parameters of my
	protection hardware.  Disconnect, which would normally draw an
	arc from the collapsing field, is no problem -- the batteries
	will always be at the same level by the time I unplug.

	Much of the lab work lately has involved the Ethernet and the
	things that connect to it.  I've been collecting the interfaces
	and software necessary to make Mac, DOS, and SPARC enviroments
	happy with each other -- apparently a non-trivial task.  I'll
	report more when things come to life and I know enough to
	describe the unix-related components to this predominantly
	internet-resident audience without getting flamed for not
	knowing what I'm talking about.  Fortunately, I'm here at Sun,
	so there is no shortage of unix, sendmail, NFS, X, TCP/IP, POP,
	and SBUS wizardry in the neighborhood.  Latest:  the IPC has
	been brought up by Ron Lee and Kevin Long, and should be
	installed as BEHEMOTH on the network this week to give bike
	developers easy access to the tools distributed around the
	net.  And John Noerenberg at Qualcomm is working on
	modifications to Eudora, a public-domain mail program for the
	Mac, to handle the human interface end of the OmniTRACS
	satellite email link.

	Those new packs mentioned in the last issue have been installed
	on the RUMP, softening the otherwise industrial appearance of
	the machine.  (Oh yeah... PACKS!  It's a touring bike!)  The
	new seat fabric is on, supported by 1/8" stainless welding rod
	donated by Madco and about 80 Panduit black cable ties.  And
	Dave Berkstresser's freehand midnight milling madness has
	yielded a sort of art deco seat-and-steering assembly.  This
	was done at the last minute to make the bike ridable for last
	week's photo session with Discover Magazine:

Another Midnight Attack
-----------------------

	The first midnight attack was the subject of a story in
	Nomadness last year, relating a wild inter-cultural adventure
	on a cold windswept beach in Humboldt County.  The latest
	occured last week.

	Discover Magazine is doing a story on all this, scheduled for
	the July issue -- coincident with my departure.  Chris the
	photographer (and his assistant) drove up from Santa Barbara to
	do the all-day shoot for the 4-page color spread, and Maggie
	pedaled down from the Santa Cruz mountains to lend a hand.

	It went well all day -- studio shots against a giant white
	backdrop hung from the roof of Sun's building 4 (sort of the
	back-forty of the Mountain View campus, largely unoccupied and
	open at the moment).  After a few hours of grinning on demand
	and generally looking high-tech, I took the bike outside for
	the obligatory afternoon-light shots on the waterfront.  That
	went well also, except for the mechanical failure of revision 1
	of the BYP mounting system <sigh>.

	At 9PM we started the big setup.  In the dark lawn next to the
	building, we hung a giant parachute from a pair of volleyball
	poles.  The smoke machine was warmed up, and the photographer
	and his assistant spent a couple of hours experimenting with
	radio-synched strobes (green for the smoke, blue for the bike,
	warm for my face).  We plugged the bike's HeNe laser into the
	trailer's 2500-volt power supply and taped it to a tripod,
	aimed at my head.  Quiet on the set...

	With the assistant generating clouds of smoke and the laser
	reflecting from a tiny mirror attached to my helmet (shades of
	the Borg), Chris went to work.  Security guards stopped to
	watch the strange spectacle:  blazing multicolored strobes
	illuminating thick smoke, a red laser beam knifing through the
	haze from my already bizarre helmet, tripods everywhere, a
	dew-sodden parachute billowing behind us.  We looked like a Yes
	concert.

	Suddenly... we were attacked by the Sprinkler System from
	Hell!  With a mighty, wet WHOOSH, the ground all around us
	erupted in showers of water, sending people scurrying in all
	directions, cursing, shouting, trying to rescue thousands of
	dollars in photo equipment while not tripping over cables and
	shrubbery.  I had my own problems:  with a yell I took off
	across the lawn, still blinded by lights, pushing the bike over
	accursed fountains in search of someplace dry.  I slowly became
	aware of a security guard jogging along behind me with a tripod
	under his arm, and remembered the laser.  Oops.

	It turned out that I had towed the tripod via the Uniphase
	laser head, ripping the high-voltage cable from the
	unserviceable assembly, and the guard was trying to help.
	Fortunately, no sparks flew...  and the photo session was
	mercifully ended.  So was the life of my laser.

	And you thought this fame 'n glory biz was easy.....

----------------------

	12.5 weeks and counting.  Maggie, my erstwhile traveling
	companion, pedals north May 1 with Ryan recumbent bicycle,
	trailer, Daylab portable darkroom, laptop, solar panel, 2-meter
	Icom HT, and Venus Biscuit Snow (the cat).  She'll stop at the
	Kinetic Sculpture Race in Eureka over Memorial Day, then will
	be in Alaska by the time I truck BEHEMOTH off to Omaha to start
	RAGBRAI.  Already we're talking of a winter rendezvous in
	New Mexico.  When the relationships of nomads evolve, the
	implications can be bizarre...

	One last note:  HELP!  I need a smart gofer, preferably someone
	young enough to not cost a fortune and excited enough about
	technology to view this as a bonanza for its own sake.  I'll
	also pay somewhere between $5 and $10 an hour, depending on the
	person and skills.  The list of clearly-defined tasks is
	growing, and includes holding things, chasing around the valley
	for stuff, doing database entry, organizing inventory, keeping
	me motivated when I slip into the wall-staring phase of
	engineering, filing technical literature, answering the phone,
	helping with fabrication, shipping packages, cleaning up, and
	filtering out background noise from the universe.  Before I
	soak up lots of time with a personnel quest, I thought I'd
	check with you.  Know anyone quick witted and interesting who
	is available RIGHT NOW for part-time help, at least partially
	during business hours, for the next 3 months?  In my youth, I
	would have jumped on an opportunity like this... there will be
	contacts galore for someone who can use them.

	Back to the massive TO-DO list.  Cheers from the Bikelab!

		Steven K. Roberts 
		Nomadic Research Labs 
		P.O. Box 2185 
		El Segundo, CA 90245

		wordy@bikelab.Sun.com (primary internet)
		GEnie, MCI, or AOL:  wordy

