Thursday, May 18, 2017

Cargo Bike Dreaming

It was a dark and stormy night, and the bicyclist was thinking about adding some bodywork to his bike...

Most electric bikes are designed to look and function like a regular bike, which makes them easy to substitute for regular bicycling use.  However for my purposes being able to carry 2 bags of groceries and a 40 pound bag of dog food (and sometimes a dog too) over 10 to 20 miles is necessary.  It would be even better if there was protection good enough to handle 90% of the weather.  And I'd also like to extend the range from 70 miles to 120 miles and still take only a few hours.  As I think about building another bike, here are a few loosely connected ideas that help to define the outlines of what I'd like to build next.  None of them will do everything I would like- but some combination might work.

Saab 92001 prototype, 1947.  Drawing credit: probably Saab
Notice the fender wrap around the front wheel.  Normally this would limit how far the wheel could turn for steering, but Saab made the body extra wide for clearance.  Could this be made to work on a bike for aerodynamics and rain control?  A solar panel mounted over a bike front wheel would be about 22" wide, but I'm also trying to keep everything small and light.

Cedric Lynch in his 2 hp, 60 mph streamliner, UK.  Photo credit unknown
This is not a bicycle- there are no pedals, he's using moped speed rated tires and turn signals, and it's registered.  The bottom part of the doors hinge open so that he can put his feet down at stops.  One report credits this enclosed electric scooter with 24 to 26 Wh/mile and a 150 mile range at 40 mph speed, and another report with a newer battery pack lists a 150 mile range at 50 mph.  My bikes generally use about 11 Wh/mile at 15 mph, 16 Wh/mile around 18 mph, and maybe 20 Wh/mile around 20 mph, (depends on how hard I'm pedaling, weight, wind, etc), so the streamlining is definitely working (he is also using a very efficient motor),  I think this photo was taken around 2000, and Cedric has since moved on to building more powerful motors,   It is possible to get a lot more sophisticated than this bike, such as a Carver OneLIT C1,  EcoMobile/MonoTracer/ZeroTracer or MonoRacer, but this is closer to what I'd like to build.

Hudson J-3A streamliner locomotive, aka the 20th Century Limited, designed by 
Henry Dreyfuss for NY Central RR, 1937. Photo credit Robert Yarnall Richie via Wikipedia
Operating speed for this steam locomotive was about 55 to 65 mph, and it's fuel was coal.  (Trains of this 4-6-4 configuration could sometimes reach 100 mph on long flat routes.) This was built during the period of "modern" streamlining.  I like the comparison of this locomotive to Cedric's early scooter above, but his later scooters look more like locomotives designed by Otto Kuhler for ALCO.

Go-one 3 early version, (currently go-one Evo-R with a full tail), photo credit unknown
This bike is appealing because of it's lightness, the smooth shape and easy to access rear mechanicals, but with a regular (i.e. larger and heavier) velomobile like a Quest or Mango I could also make a space inside the back section to carry groceries protected from the weather.  If I'm building a fully enclosed body, I'd also like to try to put more than 200 Watts of solar on it and the long hood on a regular style velomobile could possibly fit 100W to 150W.

Tōkaidō Shinkansen N700 series train at the Maibara station, Jan 2011.
Photo credit: spaceaero2 (via Wikipedia)
This train has an operating speed of 175 mph, and uses 25 kV AC electric power.  It looks a bit like the Porsche 919 LMP (Le Mans Prototype) race car I mentioned in my Bicycle Bodywork (4 of 4) bike fairings blog post, and actually both vehicles are running at about the same speed.  This body style could blend well with a solar panel on the roof.
Pennsylvania Railroad K4S locomotive, designed by Raymond Loewy, 1936.
Photo credit: Altoona Factory Works photographer, reprinted by
Interestingly Raymond Loewy was heading in the direction of wide front aprons with a central Vee on his locomotive designs in the 1930's, but he still had to keep a prominent round nose for the front of the boiler instead of a driver's cab.  The Shinkansen aerodynamics are probably better quality- most likely they've actually been tested in a wind tunnel.

Bike2c24 Ristretto at the Nokia Finland test track, 2012, Photo credit: Bike2c24
Back to two wheels.  This bike is beautiful, and it's fast too.  It's like the human powered speed record bikes, except that you can see out of it.  Since I'm trying to stay below a 750 watt motor limit this design is very enticing, but it wouldn't fit many groceries.  Also it wouldn't work very well on my 2.5 miles of dirt road, and at least with Cedric's bike I could put my feet down when stopping.  But it's pretty tempting... I do like this bike a lot... I could talk myself into it...  Now that I think about it maybe 150 watts of solar could be draped over the back section, and maybe a 350 watt hub motor in each wheel might help get it through the mud - interesting - I wonder what the top speed would be, let's see, they set a Finnish one hour time trial distance record of 49 miles, and a sprint top speed of 60 mph using only human power?  Hmm, how much bigger would it have to be to fit groceries?  I'll have to figure out how to stick my feet out...

Google Doodle in celebration of Raymond Loewy's 120th birthday, 5 November, 2013

Bernard Cauquil riding along in Turkey.  Photo Credit: Florian Bailly
Suntrip 2015, 
 This bike has about 450 watts of solar panels overhead, which could be made rainproof for weather protection.  Bernard traveled 7000 km in 25 days (an average of 280 km per day), or about twice the distance of the Tour de France in the same amount of time, and while carrying his camping gear.  Raf Van Hulle on a more upright posture bike with a bit less solar arrived two days later.  For everyday use I'd like to try to layout a bike with a higher seat position for better visibility, but I still want to take my weight off of my wrists so the seat does need to be further back than on a normal mountain or road bike.  A regular kitchen chair and the seat in my car are both about 18" high off the ground, so I'll see how well that will fit into the next layout.

In earlier posts about bodywork I've mentioned the fully enclosed Belgian Velerique (which has holes for sticking out feet when stopping) and the open sided Reisefahrrad Läufer from the Mobilität Technische Universitat Munchen, but my main concern with these bikes is the tall side profile area making them sensitive to crosswinds (worse on the short wheelbase and long body length Velerique).  Some of the bikes in the Suntrip 2013 tour that had a high solar panel canopy over the rider would be tough to ride in a crosswind too.  Although a trike would solve this problem, I would still like to work with two wheels instead of three because of efficiency, speed, and the narrow roads with rough shoulders around my region.  To reduce the side profile area I'm thinking more of a fairing than an enclosed body, so that some of the crosswind can pass through it, in combination with a solar panel placed over the rider.  Another advantage of using smaller fairings instead of a full body is that I'd like to try using ABS plastic for the bodywork instead of fiberglass for better impact resistance, and it would be easier to thermoform smaller pieces.

In the late 1970's I was living far from power in the North East Kingdom of Vermont, and I tried to build some windmills (back then solar panels were very, very expensive).  I used car generators and alternators, and the windmills sort of worked but mostly they didn't.
Some of the windmill blades I carved in the early 1980's.  These weren't being used so I converted them into a sign for Hartland Energy Committee booths, such as this one at Farmfest 2009.  In front of the booth is also one of the bike blenders.

I poured through hundreds of NACA airfoil shapes and then carved some blades out of wood, and along the way I discovered sailplanes.

Erik Larson's ASH 26E self-launching sailplane. Photo credit:Russ Owens
The mid motor and propeller retract when in regular soaring flight.
Other motorized sailplanes have been built with the motor located in the nose or tail.
Materials were just becoming strong enough at that time to build long, thin sailplane wings that gave long glide ratios, and the planes looked beautiful, like soaring birds.  One of the reasons I like the Go-one 3 bike is because the body looks like a sailplane cockpit, and I don't think it is possible to have a much lower Cd on a passenger vehicle than a sailplane.  Forty years have gone by and there are now sailplanes that can launch themselves using electric motors, which have already flown across the US and over the Alps.

Sunseeker Duo first powered flights, 2014.  Notice that the plane's motor turns off and it soars, an energy management scheme similar to coasting on a bike.  Also notice that the canopy cover has flush fitting operable openings in it.  A few other high efficiency motorized gliders include the first Sunseekers, and the non solar Antares, Pipestrel, Schleicher, Viva sailplanes.  Video credit: Solar Flight

The last two main considerations in the design of my next bike have more to do with how a bike is used than with physical form, they are energy use and speed.

Energy use is a high priority for me, and the efficiency of bicycles is one big reason why I like them. My home solar array is old and small, but I've learned how to live quite well on an average of 2 kWh per day (this includes running normal appliances and shop equipment).  I've also insulated my home and use only 1.5 cord of wood per winter for heating and cooking (it's about 7000 (Fahrenheit) Heating Degree Days per winter here).  I would like my transportation to meet similar efficiency standards, which means some streamlining is necessary.  But streamlined bodywork will be just extra weight when going slowly up a hill, and may result in going too fast down a hill.  (My bakfiets and longtail routinely reach 40-45 mph when coasting down local hills with no streamlining.)  I'd like to leave out regeneration during braking on the next bike in favor of coasting to increase my average speed, (in many competitions like the Shell Eco Marathon coasting is an important part of the driving scheme), but I don't want to be riding the brakes dumping energy even more than normal when going down long hills.  Streamlining might require a different drivetrain design to make it work well.

Last but not least is speed.  I've been thinking about speed for several years now and it's still an open question.  Almost all my riding is for errands, and the time it takes often matters.  With streamlining and an electric motor it's possible to build a very fast (and legal) bike, but practically speaking where does a 60 mph bicycle belong?   When riding on a bike I love looking around and seeing things, instead of focusing down the road in a car in case you're about to hit something.  Maybe being able to substitute a bicycle for a car is the wrong question.  When I compare walking like Thoreau did versus traveling at race car speed it's easy to decide which one is more alive.  I can't help but think that while cars have some good, positive abilities, they are also more than a bit over the line in significant negative ways and sometime we'll look back and say they were great fun while they lasted, but they turned out to be just a sugar buzz.  I don't expect this to happen anytime soon, as James Woodcock and Rachel Aldred point out in their paper "Cars, corporations, and commodities: Consequences for the social determinants of health", 9 of the top 10 Fortune 500 corporations in 2006 were either car or oil companies.  I don't think addictive sweets like cars are going away easily.  So for this moment traveling faster does help my bike design coexist on roads that were built for a car culture, but it's not the only consideration, is that how we should expect moms and kids to ride too?  I think that coasting and streamlining will be more effective than what I'm doing now, but I also don't want to leave out the benefits of bicycling slowly.

Claremont Hill-Riverside Drive New York, Drawing credit: Childe Hassam
Reproduced in Scribner's Magazine, June 1895

Anyhow that's a few of the thoughts floating around in the background as I pick out the pieces for building the next bike.

Thursday, April 6, 2017

Building the Oma Cargo Bike frame

Bike builders often use a heavy metal table with custom spacers bolted on to it to hold tubing in alignment while they work, or a jig made of angle iron or extruded aluminum sections that are adjusted to fit the frame design.  If I was making more than one bike I'd build a jig to hold the frame in alignment during cutting and tack welding.  But since I'm building one off experimental bike designs, the methods that I'm using have more to do with custom cabinetry.  The design is drawn full scale and pieces are then scribed and cut to fit the pattern, using strings, templates, and other measurements taken along the way to keep the project straight and lined up.

To start the Oma cargo bike I found the flattest part of the floor I could, and taped a sheet of thin underlayment plywood (smooth on one side for drawing lines) to the floor to keep it from shifting around on the different bumps.  (I might build a low, flat, and level table if I keep doing this.)   Plywood has decently parallel edges for hooking measuring tapes and squares over, allows me to erase lines when I make mistakes, and lets me glue spacer blocks on it to position the tubes in the right locations.  Plywood does move with the weather just like wood and the corners do swell out of parallel, but over the years I've learned habits that allow me to easily work to 1/32" tolerances (which is 0.031"), and with minimal effort I can work to 1/64" (0.015") and can push it to less than half that when needed, so wood patterns are OK for a project like this.

For this bike I had an overall style in mind (the Adelaide Longbike) and I knew the dimensions of my components, so I started at the head tube and laid out the rest of the bike moving towards the back.  Making this frame was actually a lot like lofting for shipbuilding- while I didn't use a spline for drawing the upper tube curvature, I did use a beam compass, and then used triangles, squares, and blocks to build the frame over the drawing.  For example after drawing the top tube high enough to clear the front derailleur and the motor but as low as possible under the cargo box, it was simple to place the tube on the pattern to check the fit while bending and notching it.

Before cutting anything I propped up the donor frame level with some weight on it and took measurements.  The head angle is good to know because that is what the fork is built for, but the front axle to bottom bracket centerline distance, wheel radius, and the bottom bracket drop and height should be checked too.  This frame was very large, and while the head tube angle was a nice slack 68 degrees, I decided to move the bottom bracket 1.5" closer to the front axle to help shorten up the length of the bike.  

My goal is an everyday bike that can easily do many of the functions of a car, but quite a few people have told me that they couldn't use one of my bikes because it was too big for them to store easily.  This bike also turned out too big- the wheelbase is 82 3/4", which while 4" shorter than my bakfiets is 6" longer than my longtail.  An easy way to make this bike at least 12" to 18" shorter would be to move the rear wheel forward and have a hump inside the cargo box (like a Madsen cargo bike), but I decided I wanted my dog to be able to ride in the box so I left the floor flat and about the size of a car front seat.  I also kept the solar panel 6" behind the rider to reduce the butt shadow on it, but if the solar wasn't as important the bike could be shortened another 4" to 5" behind the seat.  The Bike Friday Haul A Day is proof of how popular a smaller cargo bike can be.  Eventually I'd like to build a small run of Scarlet Runner cargo bikes for people around me to use, but for now I'm still learning how to package the components of a work bike tightly.  One thing I have learned is that really good bicycles are about doing many functions with the least amount of bicycle possible.

To transition the rear chainstays to the lower tube I made a cone shaped adapter piece.  Before welding it on I welded a diaphragm across the ends of the chainstays to keep them from deforming under load.  The tubing is propped up on the drawing with blocks to the correct height to keep it straight, and then it is easy to use a try square (with one wide leg so that it stands up) to line the tube up with the drawing while fitting joints.

To fit the rear upright tube and the seat stays to the hoop that runs along the top of the cargo box, I used a short piece of hoop tubing held vertical to the drawing.  The diameter of the seat stays are a good fit to the hoop tube, but the larger rear upright will have to be welded along the bottom half first, the lips tapped closed to the hoop tube and then the weld finished.

The hoop that supports the rim of the cargo box was made of two pieces welded together.  To form the outline I simply drew lines up from the drawing of the frame at the bottom of the plywood (click on the picture to enlarge if you can't see the drawing), and then drew in the sides the same width as the solar panel that forms the lid.  I then placed the tubing over the outline as I bent it to check the shape.

Bending small radius curves without heating the tubing has been a problem.  I have a tubing roller that works very well on large radius curves (such as the top tube on this bike), but while it's possible to turn out small curves, it's too difficult.  This picture shows the results of experiments with several different dies, supports, and also techniques like welding end caps on the tube and filling it with sand, etc.  I'm finding that the small radius curves I've made so far are about 2.5" to 2.75" center line radius, which is not a common die size for commercially available tubing benders, and the tooling gets very expensive so quickly that I've started to build my own rotary draw bender instead of buying one.

Once the backbone of the frame was finished, it was time to install the hoop.  The two wood supports propping it in place have legs that center them on the frame which kept the hoop very close to being lined up, but I also ran a string from the head tube back over center marks on the hoop to the rear upright and then leveled the hoop and frame too.  With the hoop held in place, I fitted the uprights.  In the background you can see some of the shim blocks glued onto the drawing on the plywood sheet from the earlier steps.

I also decided to try a feet forward seating position on this bike, and the seat tube post is set back about 9" from the bottom bracket.  The goal was to have my feet flat on the ground at a stop.  The basic formula for this is that the distance from the middle of the top of the seat to the ground (i.e. inseam) is the same distance as from the middle of the top of the seat to the top of the pedals at full leg extension.  If you draw this out the seat actually has to adjust up and down in an arc, however the middle 6" of seat height adjustment is close to a straight line, which is what I used for setting the seat post location and angle.  I knew that I'd lose some pedaling force by not being over the pedals (unless I stand up), but this might be OK because of the electric motor assistance.  (Since my next bike will be a semirecumbent this is a good intermediate seat position trial.)  I don't have many miles of riding this bike yet, but first impressions are that it's good, but the front fork stem is far away and the steering feels like a tiller.  Since many velomobiles and recumbents have a similar tiller this should not be an issue, but I think that if I built these for others I would move the seat post an inch or two forward closer to the usual position.  When people extend their leg they naturally point their toes, (which is why setting the seat height using a straight leg and your heel held flat on the pedal works- the toe pointing reflex gives the correct bend in the knee at full extension), and this pointing slightly reduces the need for having the seat as low as the theoretical inseam height that I calculated.

The curved top tube makes it easier for people to get on and off the bike- my impression from comments on the test rides with my other bikes is that at least 1/3 of riders want easy access on their everyday bike.

After adding uprights to support the hoop, I put in a few diagonals to help brace the frame.  I curved the diagonal braces that run up to the hoop so that they would clear springs on the back of the seat, they bend inwards as well as down.  The motor mount is a weak spot, although I did include a bash bar that bolts on underneath the motor which will take some of the downwards force that would try to bend the mount open.  The next time I mount a motor like this I will use plates that attach near the axle shaft instead of around the spoke flanges.  I then added some ells to support the cargo box floor.

I had an old bent fork that I made into the kickstand, the legs turned out nice but I'm not happy with the pivot (it's too far over center and hard to use), and the chain clearance is minimal.  I plan on redoing the idler sprockets for the front chain, probably by making the front sprocket into a single gear and adding a 3 speed freewheel and derailleur to the motor, which should help the clearance.  But for now the frame was done enough to ride, and it was time to get some paint on it and make the cargo box.

Friday, February 24, 2017

An Act Promoting Work and Commuter Bicycles

I currently have a proposal in my state legislature for "An Act Promoting Work and Commuter Bicycles" by removing the sales tax on them.  It's in the VT House Transportation Committee, and it looks like it is going to "die on the wall" before even getting out of committee because of generic state budget concerns.  If you are a reader from Vermont, I'd appreciate it if you would write both the sponsors of this bill (John Bartholomew and Mollie Burke), and your House Representative for your district, and ask them to support this proposal.

Why does everyday bicycling need to be actively promoted?  Because we've had almost 100 years of heavily subsidized pro automobile policy, and our transportation system needs to be brought back into balance after the damage that this has caused.

Everyday bicycling (which includes Bike to Work) provides the greatest benefits to both the rider and society.  These include financial, health, environmental, personal well being, and societal benefits.
(click on image to enlarge)
The costs in this infographic are based on urban Vancouver, B.C. transportation.  They appear to include personal and municipal costs and some health and environmental costs (immediate but not catastrophic), but not all costs of ownership.

 Automobiles are highly subsidized.  There have been roads for thousands of years, but the automobile is effectively less than 100 years old.  The first automobiles were built in the late 1800's, but the auto did not become common place enough to affect the average person's life until the 1910's.  In much of the US around 1930 only every other family owned a car.  The car centered lifestyle we now have was built in less than 90 years.  We should be questioning whether this is an appropriate use of technology and resources, or whether it is a prop for the obsessive compulsive side of our human psyche.  Indeed, the better explanation of why we are willing to pay so much money for 38,000 fatalities (over 3000 a month) and 2.3 million injuries (half of which are disabling) each year in the US, (not to mention the 700 bicyclist or 4000 pedestrian deaths) is addiction.  If you do not think that you are addicted to your car, then try to stop using it.  Our transportation system did not have to be built this way.

Blue Hills Parkway at Brook Road, Boston, looking towards Mattapan, August, 1914
Photo credit; Massachusetts State Archives, reprinted in:
Old Wheelways, Traces of Bicycle History on the Land, by Robert McCullough
In addition to all season pathways for pedestrians, bicyclists, and the travel lane, Blue Hills Parkway designer John Charles Olmsted recognized in 1914 that many residents of the outlying city districts were unable to afford carriages, and included an electrified trolley line to serve them.

My father owned an Austin Healey sports car when I was a child, and I have played with Porsches.  I'm well aware of the joy of a pleasant motor ride through the countryside.
1950's Austin Healey Sprite, Photo credit
This world does not exist anymore.  Vehicle Miles Traveled (VMT) has more than doubled since I was a young driver, and the most common driving experience now is to be stuck in traffic.  If you want to motor down the road like I did, then half the cars have to be removed.

The roadway design that was acceptable for 1950's traffic is marginally criminal now, it's long term effect has been to promote only one road user.  Our car centered transportation policy developed post World War 2 with little thought to anything more than level of service, throughput, and speed.  But humans are squishy little marshmallows and don't survive hitting bridge abutments at 40 mph, so our cars have become safety cocoons that disconnect us from the world around us.  Unfortunately this does not remove the effect of cars on the world.  We now have whole populations of school children who can't breathe because of asthma from tailpipe emissions, and a general obesity epidemic.  In 1969 48% of kids rode their bike to school, in 2009 only 13% did.  Our transportation policy has deliberately moved schools to the outskirts of towns, making the bicycle rides longer while simultaneously increasing the number of cars.  (See Safe Routes to School for more info.)
Credit: Yehuda Moon

Our car centered transportation policy is seriously short sighted.  We know that distracted drivers are a major cause of crashes, but we have yet to admit that those drivers are not there to enjoy motoring down the road.  Wouldn't they be better served on transit where they can check email without the distraction of driving?  Wouldn't active transport (walking and biking) for short trips improve our health and personal connections?  Or a more fundamental question- why is it OK that we are now commuting huge distances?

This is the result of 105 years of our current car centered transportation policy.
Genesee Street, Utica, NY in 1910 above, and in 2015 below, after American Urbanism
Photo credit: Built Brooklyn
And here is an even more fundamental problem- you may like Genesee Street in 2015 because you grew up on a street just like it and it feels comfortable, however it is not a functioning landscape.  Natural ecosystems do not work this way, and it's turned out that human society does not function well this way either.  This landscape is all about the car, not humans.  A huge lack of diversity, social equity, or inclusion is required to make this landscape work.

"We shape our buildings, and afterwards our buildings shape us."  Winston Churchill

"Nature is not a place to visit.  It is home."  Gary Snyder

"Bicycles are the indicator species of a community, like shellfish in a bay."  P. Martin Scott

"First, from a technical viewpoint, all negative externalities depend on speed, often significantly. On the one hand, they all increase beyond 30 to 60 km/h (20 to 40 mph). This is true not only for the most studied nuisances - noise, pollution, accidents and congestion (OECD, ECMT, 2007) - but also for less studied nuisances, such as severance effects, land use and urban sprawl, social segregation, or the disqualification of non-motorized modes."  Frédéric Héran, About the Effective Speed of Transport Modes: Ivan Illich's concept revisited, 13th World Conference on Transport Research, Rio, 2013
Photo credit:  Wes Craiglow, Deputy Director Planning & Development, City of Conway, AR
The way we think about transportation is flawed.  Technology has changed our concept of what the car is and what the car does.  With the increased levels of automobile use that we are seeing, our old paradigm of traffic management is broken.

"Much of the opposition to cycling schemes is based on a belief that motor traffic is like rainwater and the roads are drains for it.  If you narrow the pipe, these people say, it will flood.  If you block one route, they say, the same amount of traffic will simply flow down the next easiest route.  But that seldom or never actually happens in practice.  Because traffic isn't a force of nature.  It's a product of human choices...   Officially the cycling programme is about cycling.  In reality, it is about breathing.  It's about pollution, about health, about noise, about the kind of city we want to live in. It is about making the best use of scarce space on public transport.  Most of the people who will benefit from the cycling programme aren't cyclists.", Andrew Gilligan, Cycling Commissioner, Human Streets: The Mayor's Vision for Cycling Three Years On, Greater London Authority, UK, 2016

Do I expect "An Act Promoting Work and Commuter Bicycles" to solve all this?  No, this problem has been building for 90 years and it is much too big and deep,  Actively promoting everyday bicycling is a small beginner's step, but at least it goes beyond the "helmets and hi visibility clothing that politicians love because they don't actually have to do anything other than shifting the responsibility for it all onto bicyclists" (Анастасия Ромашкевич, Правда и ложь о светоэлементах, VeloNation), and is actually supporting a mode of transport other than the car.

Credit:  Adam Zyglis, The Buffalo News
We choose the car for our trips because it is easy.  It is now our job to make walking and bicycling just as easy.

I've tried to calculate the costs of this Act for our budget people, and here is my best estimate:
1.  Vermont sales of bicycles, related parts, and accessories in 2012 (Bicycle Retailer and Industry News (BRAIN) Annual Stats Issue – August 1, 2014)
2.  Corrected to 2015 (national sales of $6.5 billion in 2012 versus $6.2 billion in 2015, or a decline of ~5%) (National Bicycle Dealers Association 2015 Statpak – Industry overview)
3.  Adjusted for proportion of retail sales at shops due only to bikes (47.4%) (National Bicycle Dealers Association 2015 Statpak – Industry overview)
4.  Adjusted for portion due to commuter and utility bikes (6%) (an estimate based on both Alliance for Bicycling and Walking, and People for Bikes, survey data)
5.  Vermont Sales tax amount that would not be collected (6%):
My estimate of the market share of work and commuter bikes is the most unreliable figure above, the national average is around 10%, but this would be quite high for Vermont because of the effect of the large California, Texas, and Florida markets.  The overall mode share of people commuting by bike in Vermont is a fraction of a percent, and combined with declining bike sales at a time when we actually need more active transport, only underlines the need for a transportation policy that proactively supports bikes.

The Return On Investment (ROI) for this $46,546 could run from 7.8 to 1 (Helsinki Bicycle Account 2015 using the World Health Organization- Health Economic Assessment Tool), up to the 20 to 1 derived in several studies of the health benefits of bicycling.  This would be a return of $363,000 to $931,000.  A typical scientific analysis out of these several would be "Moving Urban Trips from Cars to Bicycles", Australian and New Zealand Journal of Public Health, 2011, which concludes:
"Results: Shifting 5% of vehicle kilometers to cycling would reduce vehicle travel by
approximately 223 million kilometres each year, save about 22 million litres of fuel
and reduce transport-related greenhouse emissions by 0.4%. The health effects would
include about 116 deaths avoided annually as a result of increased physical activity, 6
fewer deaths due to local air pollution from vehicle emissions, and an additional 5
cyclist fatalities from road crashes. In economic terms, including only fatalities and
using the NZ Ministry of Transport Value of a Statistical Life, the health effects of a
5% shift represent net savings of about $200 million per year.
Conclusion: The health benefits of moving from cars to bikes heavily outweigh the
costs of injury from road crashes."
Since this report was published in 2011 there have a couple of studies showing that the more bicyclists there are, the lower the crash rate.  Shifting 5% of vehicle kilometers to cycling should result in less than 5 additional cyclist fatalities.

As far as I know California is the only other state with a similar working and commuting bike proposal (here is a good summary on Streetsblog).  I've had the chance to speak with Jeanie Ward-Waller, Policy Director for the California Bicycle Coalition, (, and their proposal is strongly focused on transportation equity.  Their incentive is much larger than my sales tax exemption proposal, however they expect a more complicated qualification process, compared to the simple test for a work bike that I'm proposing.  Both of our incentives face the same budget opposition though, and both could use support.

I still enjoy Porsches, and I do think Electric Vehicles are important.  But there are some deeply serious problems with the transportation system we have built, it's all been short term gain.  We need to support active bicycling and walking.  We have left the human out.

Copied below is the proposal I gave to the Vermont House Transportation committee, it has not received a Bill number yet.  In it I reduced all of the benefits of this proposal to short summaries for the legislators, but if you would like to follow up please feel free to send an email and I'll try to connect you with references.

An Act Promoting Working and Commuting Bicycles

Introduced by: Representatives John Bartholomew of Hartland and Mollie Burke of Brattleboro

Date: January 2017

Subject: Transportation, energy, greenhouse gas emissions, traffic planning, Complete Streets, First mile/Last mile, public health, social equity

Statement of purpose of bill as introduced: This bill would promote the use of Bicycles used for working and commuting purposes through a sales tax exemption incentive.


Working and Commuting Bicycles have:
-Tires wider than 1” and less than 3” wide
-Seat wider than 5.5”
-Rack(s) installed or mounts for racks built into the frame
-May have an electric motor assist, which must meet the requirements set forth in the 2016 Vermont Transportation bill for electric bicycles.

Sales tax exemption:
-Similar to the procedure that is currently in place for renewable energy equipment

Background explanations for the Committee:

This incentive covers bikes that are a practical replacement for a car, which includes:
-a regular frame commuter style bike
-a cargo bike with an extended capacity frame for carrying larger loads
-a commuter or cargo bike with an electric motor for extended range and/or cargo capacity
-electric motor conversion kits for bicycles (both a DIY route for owners or installation by a bike shop)
This proposal is not meant to cover sport bikes, but the committee may wish to extend the incentive to include them because they share some of the benefits of work and commuter bikes.

Choice of Sales tax abatement for an incentive:
The price of bicycles suitable for work purposes can vary widely from $100 bikes to $5000 or above. An incentive based on a fixed amount such as used in many Electric Vehicle incentive programs would not work well, but using a sales tax abatement would automatically link the incentive amount to the price. This amount would also be approximately in line with many EV incentive programs.

Reasons for encouraging working and commuting bicycle use:
These include meeting state GHG emission goals, Vermont Comprehensive Energy Plan goals, reduced road congestion and wear, achieving Complete Streets and local community benefits, helping First mile/Last mile issues, public health benefits, and social equity.   A brief summary of each follows:

GHG emission and VT CEP energy reduction goals:
-Bicycles produce 10 to 12 times less GHG emissions and use about 90% less energy than automobiles.
A. The European Cyclists Federation found that the complete life cycle emissions in grams of CO2 per passenger per kilometer for various forms of transportation were:
-Bicycle 21 g
-eBike 22 g
-Bus 101 g
-Passenger car 271 g (for average short trips)
Source: “Cycle More Often 2 Cool Down the Planet: Quantifying CO2 Savings of Cycling”, 2011
B. Shreya Dave at MIT using Carnegie-Mellon's EIO-LCA methodology found that:
-Electric bicycles use less than 10% of the energy required to power a sedan for each mile traveled and emit 90% fewer pollutants per passenger mile-traveled than a bus operating off peak
-walking, conventional bicycling and electric bicycling release exactly the same amount of greenhouse gas emissions
-All forms of human powered personal transport are at least three times better [for emissions] than any other form of commuter transport.
“Life Cycle Assessment of Transportation Options for Commuters”, February 2010

Reduced road congestion and wear:
-A working or commuting bike replaces a car, and will take up about 1/10 the road space, which helps traffic planning, traffic flow. and parking in urban areas.
-Cycling infrastructure is also much less expensive than infrastructure for cars, helping to reduce road budgets for similar traffic capacity.
-Road wear is proportional to the 4th power of the axle weight, and in general a 250 pound bike will have 1/1296 of the road wear that a 3000 pound car does, which is beneficial for highway maintenance budgets.

Complete Streets and local community benefits:
-Complete Streets design guidelines create a roadscape suitable for multiple users, and this incentive would help to encourage bicycles on those streets.
-Local community benefits derive from the range of a bicycle. Approximate distances based on historical trolley stop settlement patterns from the stop to a house are about:
Pedestrian 0 to 2 miles
Bicycle 1 to 5 miles
An electrically assisted bike can on average double the bike range to 5 to 10 miles.
Thus a bicycle commuter or consumer will be doing business within their local area. which promotes down town businesses, center of towns and local economies.

First mile/Last mile issues:
-Promoting working bicycles helps not only commuters that ride a bike directly to work, but also those with the First mile/Last mile problem that is connected with Park and Rides and transit.
-Increased use of commuter bikes will also fit in with Amtrak's new program for carrying bicycles on the Vermonter train line.

Public Health benefits:
-Americans have an obesity epidemic, as well as cardiovascular issues, and a rising diabetes problem that are primary concerns for public health. Exercise has been shown to help these problems, and bicycling is one of the preferred exercising methods (second only to swimming), for being easy on joints while still providing a beneficial cardiovascular workout.
-In addition biking to work is a mild exercise that is repeated as a daily routine so that it provides a continuing benefit. Many studies have shown that the health and medical benefits of regular bicycling outweigh the risks by around 20:1.

Social equity:
-In 2016, the California Bicycle Coalition (CBC), along with several coalition partners, presented a petition to the California Air Resources Board (CARB). The CARB distributes funds for the Clean Vehicle Rebate Program (CVRP), which offers rebates for electric vehicles, and CBC is asking them to expand their rebate program to include “the cleanest vehicle of all: the bicycle”. CBC is seeking the creation of a $10 million Bicycle Purchase Incentive Pilot Program. The program would rebate half of the cost of bikes that are commonly used for commuting, up to a maximum rebate of $500. Under the program, California would pay for half the cost of cargo bikes, electric bikes, folding bikes, bike share, and other utilitarian bicycles used for everyday transportation. The CBC finds that in addition to the cleanest vehicle being excluded from the CVRP, that the CVRP program is also inequitable and discriminates against both low income persons and limited income families who do not own or can not own a car.
The CBC letter to CARB can be found at this site:
-A second consideration is that for children and young people cycling and walking are the only forms of independent transport.

For further questions, please contact:
Karl Kemnitzer
My Solar Electric Cargo Bike, Scarlet Runner Bikes, VBike

Saturday, February 4, 2017

Longtail construction (3/3) finishing the frame

Once the main part of the frame was welded together, I began to add the smaller pieces.  I started by making a hoop out of 7/8" tubing for the foot support.  I made the bends a large radius because the foot support is at shin height, and sharp corners could easily hurt.  The front of the hoop is 16 1/2" back from the crank center line to give enough room for heel clearance when pedaling, but I still occasionally bump it when walking the bike.  I also decided to add on a trailer hitch so that I could carry very long pieces of wood, and made the back of the hoop long enough to go around the tire.  On top of the back I welded on a small piece of 3/16" plate for mounting the hitch.

I used a 3/4" EMT electrical conduit bender that had a 5 1/2" center line radius.   Since I would custom build my trailer, I simply used a 1/2" bolt with the head cut off sticking up from the plate for a connection pin instead of a more standard bicycle hitch.  A common Heim joint mounted on the trailer tongue can then be slipped over the pin and secured with a hairpin spring clip through the bolt.  This setup is much less expensive and stronger than a standard bicycle hitch.

I started the kickstand by fitting a template cut out of cereal box cardboard to the bottom frame tubes.  Using this type of cardboard works well because you can bend or fold it for fitting 3 dimensional patterns easily, but you can also draw grids on it when it's flat to keep the pattern square and straight.  You can then use it to line up the parts for tack welding them together.  I like to build the kickstand so that it lifts the tire only 3/4" off the ground.  Some people prefer 2" to 3" in case the kickstand sinks into the ground, but I think that just makes it harder to use.  I prefer to add foot pads to the legs instead.

I've now built 4 heavy duty kickstands, and while they all work OK, I don't think they are particularly good designs.  I've started to think it's one of the hardest parts of a bike to design well.  If I want to know if someone is a good bike builder, I've now started to look at their kickstand.

With the tires temporarily installed in the frame for measuring the kickstand height, I noticed that I had miscalculated the chain line and two diagonals were in the way.  Oops.  I cut out enough to clear the chain and replaced it with an ell piece that has a brace on the backside to stiffen it.  This gave me a chance to test my weld- I squeezed the cut out tubes together at the top, and they crumpled without the weld at the bottom giving way.  

Besides the chain line repair and the kickstand, I started adding other tabs, such as a bracket for chain idler sprockets, and tabs on the hoop for attaching the plywood foot boards.

The foot support hoop was propped up level and tack welded at the front to hold it in place.  Then I added two diagonals at the back running up to the rack, followed by stays to the rear dropouts.  I ran braces from the dropouts sideways to the hoop to take the side forces, but had to make two compromises- they had to be moved backwards because the right one interfered with the derailleur, and I had to use a sharp mitered corner to fit the tube under the plywood foot board.  The corner hasn't been a problem though because the sharp points are hidden away from most activities.

I also fit cross pieces to the rack for attaching it's deck board, and included a downward ell on the rear piece for attaching a light.  However I ended up replacing the reflector I had there with a much brighter LED truck side marker light, which I attached to the fender with automotive double sided foam trim tape.  All of my bikes have a small 15 watt DC to DC converter to convert the battery's 48 volts down to the automotive 12 volt standard, and regular car components like lights and GPS can be wired in.  I'm planning on adding a 5 volt USB port next, so that riders on a trip can recharge their cellphones or notepads.

I knew that I wanted the bike to be a sunny solar electric yellow, but didn't want it to look like a bumblebee with black fenders.  Two of my great grandparents are from Ukraine, and I decided to use the sky blue from their flag on the fenders and battery box.  However in Vermont we have long winters, so everyone here thinks the colors look like a Caribbean vacation,..

The brushed on acrylic latex enamel leveled out OK, but I sprayed the next Cruising Oma bike and it came out looking nice, like it was powder coated.  I'm trying to use water based enamels that have some urethane in them, but they are hard to find, most often that formula is only available as a clear coat.

Instead of using nuts, I threaded all the tabs.  I had predrilled all the screw holes in the tabs, but left tapping the threads until after painting because they would have been clogged with paint.  This way I was also able to clamp the foot boards in place and easily drill screw holes in them through the tabs, without having to mark out the holes on the foot boards.  In a production setting this step could be done with self tapping screws instead.

Decent power hub motors need to have the dropouts reinforced, or the axle will eventually twist around.  My bikes are 750 watts, and one medium thickness torque arm on the left side will do.  First I made a pattern that ran forward 4" from the axle centerline to a clamp wrapped around the chainstay.  It goes above the chainstay, so that the drive torque will pull upwards on the clamp to keep it straight, and spread the clamp's force on the chainstay more evenly than if the bolt side of the clamp were pushing on it.  I cut it out of a piece of 1 1/2" x 1/4" bar stock, working from the end towards the bar, so that the bar formed a big handle until the very last cut.

Clamp a piece of scrap on the arm to make a rip fence for the angle grinder.

The axle hole was drilled undersize and then fitted to the oval axle.  I traced the oval hole from the washer that came with the motor onto the torque arm, and then filed the hole to match.  I used a carbide die grinder bit to rough out the oval, but because I wanted more control I mounted it in a slow speed drill instead of a high speed die grinder.

With the torque arm cut out, it had to be bent inwards to line up with the center of the chainstay.  I marked out the two bends and then used a cold chisel and a press to make the bends, but they could also be done with a vise and a pipe or hammer.

Next was a strap clamp to go around the chainstay, it's shown resting on the left side of the hammer.  I wrapped a strip of cereal box cardboard around the chainstay, folded the ends upwards to fit the torque arm, and then traced the bolt holes through the torque arm hole onto it.  After tracing the pattern onto a piece of stainless steel sheet metal, I drilled the holes, bent the ends up, and then rolled it around a bolt that was the same diameter as the chainstay.  You could also use a tab welded on the chainstay instead of this clamp, but if you do make sure that it is wide enough to spread the load out.  Chainstays are small diameter and can't resist much sideways bending from a point load, and the extra weight of a cargo bike makes the situation worse.

The finished torque arm takes the rotational force off the dropout.

The front fork legs did not have any tabs for mounting fenders, so I used the axle to mount it.  I have used plain washers (unplated) for eyelets for the smaller 5 mm stay bolts, but for the 7/16" axle I cut out some elongated eyelets and welded them on the end of the fender stays.

All the physical components have been assembled, and now it's time to add controls and wiring.

In the upper left corner of the battery box is the motor controller, and the small black box below it is an electrical data logger with GPS.  In the center is an A123 cell type LiFePO4 (Lithium Iron Phosphate) battery (48 volts x 20 Amp hours, which is about 1 kWh).  At the top front is the key switch, below it is the solar controller, and tucked in behind that is the 48 VDC to 12 VDC converter.
For the new Cruising Oma bike I'm switching to Panasonic NCR18650GA cells in a 52 volt configuration (14s7p), or about 1.25 kWh, which will be about 20% smaller and lighter.  I also have 4 different new solar controllers to try out- the Genasun in this picture works well, but it is very expensive, and it can not deal with shading issues well if there is more than one panel on the bike.  I would also like to use a different charging voltage than is available.

This bike is about 4 mph faster than the bakfiets on most trips, mainly because the bakfiets is set up for 36V, but also the aerodynamics are slightly better, and this hub motor has a faster speed motor winding.  However the bakfiets has the top speed honor, coasting down Miller Hill at 46.7 mph, and this bike has reached only 46.5 mph.  I think the bakfiets is faster when coasting because it has a gear drive hub motor with a slip clutch, and it doesn't have the drag when coasting that this bike's direct drive motor has.  Because of the long wheelbase and the relaxed head angle, both bikes respond slightly slow, and they feel very comfortable at speed.

I originally intended to put a small windshield on this bike, but too many new ideas came along so I started building another bike instead.  The basket has worked out well though for cookies, chocolate, potato chips, gloves, sunglasses, etc.

With the reflector mounted on the rack, before the LED truck side marker light was added down on the fender.

Before I got the canvas panniers, I used to have to choose between having the solar panel or a backpack on the rack.  This load is for the 12 mile (one way) trip to recycling.  Although the solar panel takes up rack space, I think it is important for fast, long distance bicycling and I'm working on fitting it in better.  The battery alone gives me about 65 miles at an average speed of 16 to 18 mph, and the solar panel allows me to move the average speed up to 20 to 22 mph and have the same range or more.  To give you an idea of the maximum solar boost possible, I took one 57 mile long trip last summer on a clear bright day, and when I recharged the battery back at home I found I'd only used a little over 1/4 of the energy.  If I had wanted to I could have gone 190 miles before the battery was empty.