The first two bikes have motors that are built into the hubs, this makes for a clean and robust design.
Geared hub motor in rear wheel, no change in derailleur setup needed.
However this is the problem:
On my road, you get your speed up on the 7 to 12% grades for the 18 to 19% sections.
When I ride over to Woodstock, it is easier to get off the bike on the steep sections and walk. This isn't as bad as it sounds, because I can turn the motor on low and have it pull me and the bike along. (This would not be possible with a Pedelec or BionX style throttle control.) To put this into perspective, in my car this is a second gear hill under good conditions, and when there is washboard it is first gear at 5-10 mph, which is not much faster than the bike.
The solar electric cargo bike motor is currently set up for 500 watts of power, which isn't enough for riding up this hill. There are a few ways around this limit:
-I can reprogram the controller for more amps. This is easy, but drains the batteries more quickly and the motor will run hotter.
-I could put on a different battery with a higher voltage than the current 36 volts, (this is called over volting), as the motor is rated for up to 100 volts intermittently. This is more expensive.
-A second motor and extra batteries would do the job:
Fast 2WD Electric Bicycle- Top Speed 50 mph, video credit: RNickeyMouse
Since my goal isn't 50 mph, but going up the steeper hills around my area, it is also possible to use a regular power level motor and battery pack, and connect it as a mid drive to the pedals so that the derailleur gear reduction system is used, just like shifting to a lower gear in a car. I've been avoiding a mid drive because:
-it is more complex (more things to wear out or break)
-at the higher power levels it wears out chains and sprockets quickly
-2 pawl freewheels don't like the power, so a good quality freewheel is needed, and a freehub is better
-if you shift without letting up on the power you can break stuff
-they are generally noisy- the good ones sound like a turbine (which is neat), the bad ones destroy any chance of a pleasant bike ride
-the width must fit between the pedals, so it must use a small motor, or a second chain to a remotely mounted motor
-a few bikes use the one regular chain, with the motor drive tied in to the upper chain section. This gives you only the gears on the rear wheel, and it can not use the front gears
-many mid drives extend the gear reduction train upwards, which raises the center of gravity higher than a hub motor. However I don't think this matters anywhere near as much as where the battery is mounted, and both types of bikes commonly use the front triangle or rear rack. I've ridden a bike with a very large battery on the rear rack and it tended to oscillate. One way some riders are getting around this is by carrying the battery in a backpack, such as in the video above, and also on some European mountain eBikes.
I'm trying to design for average riders and average budgets.
Of course it is possible to get a little obsessive about a mid drive setup:
Astro 3210 RC motor homemade setup running at 7000 rpm, photo credit: electricbikes.com
Which usually results in something like this:
Electric Downhill Bike (66 mph run), video credit Kim Reeg
Unfortunately this kind of usage is a pretty heavy draw on the batteries, there is a large aerodynamic drag and the range suffers. I don't think there will be many of these bikes, as it is just too complex and costly. In addition to the drive setup, you also have to upgrade hubs, rims and front forks, and start using moped or small motorcycle tires and brakes. For a cargo bike it needs to be a little more balanced, trading off some of the performance for better range.
Many countries in Europe or Asia have set a power limit of 250 watts for electric bikes, or about the power of a professional bike racer. While the solar electric cargo bike's average energy draw is 196 watts, in real life this turns out to be too small for getting the bike and cargo up many hills, and the power draw goes up to the 500 watt limit while speed drops. I can imagine riders that aren't in good health wanting more power. Most European manufactured drive systems (AEG, Bosch, Conti, MPF, Panasonic, Yamaha) have 250 watt motors and must be built as a mid drive gear reduction system to make it work- you shift down and just go slower. I think it would be easy to overload a 250w motor while hauling loads in Vermont and greatly shorten it's life. However the 500 watt hub motor is close, and with gearing added might be a respectable ride up my hill. Looking around for good mid drive examples, Audi's eBike is pretty well balanced and has received a lot of positive comments:
Audi e-bike, at Worthensee show, ridden by Julien Dupont. The bike in this video probably is traveling around the legal European electric bike maximum of 25 kph (15.5 mph), and you will notice that Julien is riding with his helmet unsnapped. It also has a few things that could easily be left off of a cargo bike, such as the carbon fiber frame and wheels, and wifi control. Most bikes like this have a custom gearbox at the pedals with slip clutches for the pedals and motor, and internal gears.
The geared hub motor was a blast for 500 miles last season, and I will continue using them, but I admit to my usual need for speed up long, steep hills (or at least riding instead of walking), so I am thinking about mid drives. I also want the assist to be strong enough for people with different levels of health to be able to ride. There is plenty of power available from an electric bicycle, as you can see from just a few seconds of this video:
Extremely high power tadpole trike, video credit Matt Schumaker
Gearheads. I'm just going out for groceries.
The design problem is how to trade some of the power for range, but still have it there for the hills. There are several ways of connecting a motor as a mid drive, and I'm waiting for all the Christmas presents to arrive so I can start experimenting.
When I'm talking with people at events about replacing my car with the solar electric cargo bike, the elephant in the room seems to be safety. I am often asked if I wear a helmet by a person with a concerned look on their face. For the most part I answer a polite "Yes" to avoid being misinterpreted, because it is a subject too complex for a half minute visit. However a large obstacle to more widespread use of bikes for everyday purposes is the sense of comfort a rider experiences, so this issue needs to be covered.
I'm well aware that helmets are a contentious issue, as I've been riding motorcycles for almost 50 years and have heard a lot comments about them since day one. (Maybe the reason this post is so long is because of that experience.) I'm also sure there are some very serious people with strong opinions reading this that think safety is not open for discussion, so I'd like to start off with this absurd video:
The difference between an accident at 30 mph and 50 mph.
Next, I'd like to repeat that I am not an rabid bicycle advocate. I've owned cars, motorcycles, bicycles, horses, and have driven all sorts of construction and farm equipment. I learned very young from some motorcyclist friends that cars were dangerous "cages", but I was too in love with Porsches for that to sink in very far. I've been part of automobile, motorcycle, and thoroughbred horse racing efforts, and I've gone very, very fast, but I also love walking. My viewpoint is about as open and equal use of the roads as anyone can be.
The prevalent concern now about bike helmets does not fit with my past experience. Why does there seem to be such a widespread emphasis? In some people it was borderline fear. I had ridden my bike everywhere around town solo without a helmet for a dozen years when I was a kid, and taken some awful spills. But overlapping with this time, I had also ridden a motorcycle off road for 6 years before getting my drivers license, wearing a 3/4 helmet (covers down past the ears but not the face). Both the bike (on the road on steep hills) and motorcycle (off road) top speeds were similar (about 45 mph), but I got hurt more seriously on the motorcycle even though I wore a helmet. Nowadays I use a full coverage helmet when on my motorcycle, but on the bicycle? I needed a more complete viewpoint.
Reading through websites about the effectiveness of bicycle helmets to find an answer, it became apparent the authors were polarized, just like the earlier motorcycle helmet arguments I'd heard. Several studies proving helmets reduced injury would be followed by several saying they did not. A few even concluded that helmets made injuries more likely, or that a decline in head trauma was matched by a rise in neck trauma. Both sides had reputable studies from hospitals, universities, health care institutions, or government transportation agencies. I was truly 50/50 about wearing a bike helmet- if even the meta studies could not consistently agree on a conclusion, then there was no trend for me to support. After 23 injury studies I gave up.
My personal usage position was that a half coverage bike helmet is almost a joke compared to my full coverage motorcycle helmet. There is minimal side, face, or back impact protection, and the ability to take a hit is a small fraction of the motorcycle helmet's thick molded shell and lining. (I believe one actual bike helmet standard is protection from a fall frontwards while standing, which would be a drop of five feet with minimal momentum.) The bike helmet's main protection will be for a mild impact to the top of your head. It probably will help somewhat in other situations, I've learned from off road experience that even leather gloves and decent clothing will help keep your body together in a crash. If you want to wear a helmet I would not discourage you. But the constant promotion of bike helmets seemed out of proportion to their value, and started to make me feel cynical about them, like this:
Good safe bicyclists on rock wearing helmets! Bad unsafe pedestrian on left without one!
Source: Kejeragbolten, Norway
I did come across one piece of information I could support:
This identifies speed as one of the main factors in the severity of injuries, (in other words go slower if you want to be safer). My plans for fast cargo bikes had hit a bump in the road.... Perhaps if I kept it under 30?
Since the studies of accident injury data had been so inconclusive I stepped back to traffic fatality statistics, because they are much more black and white, someone is dead or they are not. Here are national statistics for the US:
Source: National Highway Traffic Safety Administration, Fatality Analysis Reporting System (FARS)
So in 2011 there were 677 bicyclists that died. That was definitely not good, and should be improved. There were also 4,432 pedestrians that died, however I don't remember hearing any safety messages that I should wear a helmet when walking down a sidewalk, and there is not 6 times as much concern over the dangerous activity of walking. Of course there were even more motorcyclists that died - 4.612 - because they have a reputation for being very dangerous (sorry, cynical again). But most interestingly, 22,448 occupants of vehicles died- when was the last time you wore a helmet in your car?
It is surprising that bicycle fatalities are so low compared to cars, because there are known to be idiots doing stunts on bicycles (I did), but in general cars are equipped with seatbelts, impact bumpers, collision crumple zones, safety glass, air bags, carefully designed dashboards, and they form a protective cage. The safety campaigns about bicyclists wearing helmets seemed very misplaced. What was going on?
To be sure that the figures weren't anomalies, I checked the Vermont fatality statistics:
Source: Analysis of Fatal Crash Data: Vermont 2006-2010
Bicyclists are the bottom line. In 2006, 2007, 2008, and 2009 no bicyclists died, and in 2010 one died. In comparison the total other fatalities for those years were 87, 66, 73, 74. and 70. I do not wish to make it seem like a rider can't get hurt on a bicycle, but on the other hand it appears to be one of the inherently safer forms of traveling- it is slower and simpler. The message of how dangerous biking is really does not seem to mesh well with reality.
Another way to look at this data, is that no vehicle exists that will keep you safe in a crash. Not walking, not bicycling, not cars, not trucks. or for that matter from recent news, not planes or trains. The impermeable safety of your car is an illusion. Also, the faster you travel, the more severe the injuries will be. The 50/50 chance of survival point for pedestrians appears to be a little bit above 30 mph. The conclusion I reach is that the best path to safety is minimizing the chance of crashes, not protection afterwards.
I should also say that there are approximately twice as many bikes in the world as there are cars, (many governments do not have accurate statistics on bikes), so lower accident statistics for bikes are not because there are less vehicle miles traveled than cars.
I apologize for not finding citations for this, but I know that falls are a leading cause of injury and death, particularly for seniors. Logically there should there be an OSHA safety campaign ensuring everyone wears a helmet around the house, especially elderly people going down stairs and people going to the bathroom.
It was time for a reality check. I started looking at pictures and videos to see how riders in other parts of the world used helmets. I noticed that despite very few riders in Copenhagen or Amsterdam wearing helmets, there were no reports of horrible survival rates when riding a bike, even though that biking population is upwards of a million people, and rides over 2 million kilometers each day. Then I noticed that through out Central America, and down into South America, there were almost no helmets, their Ciclovia's were big parties. Finally, there was India and China, with hundreds of millions of riders- definitely the largest samples- and again there were very few helmets. (I've posted some of the more interesting videos in the sidebar under "Traveling in other places".) If you look in other places, for example the wall page of Women on Wheels, (which is about women who are traveling solo around the globe, a link is in the sidebar), it has 48 riders who have a helmet on or are carrying one on their luggage rack, and 39 without a helmet. In the end, I was forced to conclude that wearing a helmet is not a requirement for riding a bike. A distinction must be made between competitive racing cyclists at 30 - 40 mph, and average commuters at 8 - 20 mph. The overwhelming majority of people in the world do not wear a helmet when bicycling.
I would ask that you take everything you feel or think you know about bicycling on Upper Valley roads, and compare it with this video. "Cycling to School, Culemborg, Netherlands" by NL Cycling:
There is so much, so different, than cycling here in the UV, (and it isn't just the separated cycling path), that I have to question whether the common conception of cycling here is correct.
Returning to the Copenhagen and Amsterdam statistics, there was a time when bicyclists were being injured above historical averages. The post war affluence of the 1950's and 1960's allowed more people to own cars, bicycle mileage dropped but bicycle accidents increased (!), and the segment of the population that suffered the most was children. In response there were many grassroots campaigns during the 1970's to prioritize transportation infrastructure for bicycles, and injury rates declined, (child deaths went from 400+ in 1971 to 14 in 2010), even though bicycle miles increased. The inverse correlation of bicycle miles traveled to injuries points out that bicycle safety is not tied to bicycle use per se, but that there is a direct connection between bicycle accidents and automobile use.
This points out that a second main factor in bicycle safety is the interaction with automobiles. And because of the speed differential, bike helmets are not going to be very effective.
Hmm, is the focus on helmets a United States car culture phenomenon? Post WW2 we relegated bicycle use to mainly sporting usage in favor of cars. I am aware that GM, Firestone, and Standard Oil conspired to buy up all the streetcar lines they could in the mid 1900's and rip them out, could helmet promotion be a similar negative marketing campaign to promote auto use? I can imagine automakers pushing back when they see data like this:
Global Bicycle Sales (upper line) vs Car Sales (lower line), source: Worldwatch Global Insights
The above graph does not include a surge in bike sales from 2008 to 2012 due to electric bikes, (mostly in China, source: Navigant 2013 eBike market summary). Also, in 2012 bicycles outsold cars in all European countries except Belgium and Luxemborg:
Bicycle vs car sales, selected European countries (others are similar), 2012,
thousand of units, see link above for sources and other countries.
In 2009 Amsterdam instituted a traffic safety campaign, urging bicyclists to wear helmets. Bicycle ridership entering the core of the city (where there are automated traffic counters) immediately dropped 5%, or about 10,000 bicyclists per day. Britain's motor safety council did the same thing, with similar results. Australia passed a mandatory helmet law in 1991, and after disastrous public health results has tabled it in 2013. (Please see the two videos that I've posted in the sidebar by urban planner Mikael Colville-Andersen talking about the Amsterdam studies. Australia can be read about at http://www.cycle-helmets.com/ ) Helmets discourage ridership. Now we are starting to talk about a truly large safety issue- Public Health -which I'll mention more about below.
Fear makes people do strange things. I define fear as the absence of life. In the sidebar I've put a link to "Culture of Transportation Fear" in the "Lets Get Serious" group, that discusses helmets and the media portrayal of bicycling as dangerous. These messages are effective, sometimes they go too far and I occasionally have to remind myself that I was able to bike when I was 10 years old, on the street, and it was Ok. As Colville-Anderson remarks in one of the videos, where ever he finds fear, he also finds someone lined up to sell you something.
I love conspiracy theories as much as the next person, but I'm not sure the auto industry is smart enough to pull off a campaign against bike riding, (look at Detroit). The impetus behind helmet programs seems to me much simpler and more deeply ingrained- we are programmed to think in terms of the automobile, this is our norm. Street engineers design for the auto, and Traffic planners plan for automobile traffic. Most bicycle helmet programs are run by government organizations whose main concern is automobiles. When something is wrong, it must be made better for the automobile, we insist that people other than car drivers wear the helmets:
Conversation with an Engineer, Source: Strong Towns
US transportation planning is not alone. In the last 4 years car ownership in China has exploded, and there has been a simultaneous surge in accidents. Traffic planners in many large cities have blamed the bicycle riders, not the new factor which is cars, and closed or narrowed down bicycle lanes. This is a catastrophe for China's congestion and air pollution problems, so Beijing has had to order the bike lanes reopened.
Unleashing the power of fossil fuels is an addictive thrill for the reptilian part of our brain, which has spent most of history at walking speed. This is like flying by jumping off a cliff.
It is hard to see our transportation from a different angle. A basic change would be recognizing cars as the more capable machines, and place the burden of fitting in on them. Theoretically a car is subordinate to a bicycle is subordinate to a pedestrian, but that is not what the design of our streets say. At the present moment a driver can simply say "I didn't see him", and be released from responsibility, thus placing bicycles subordinate to cars. What if that option was not available, and our streets were designed so that it was not possible?
Cars subordinate to bicyclists, Source Bicycle Alliance of Washington
The above photo is called "We can dream", but Copenhagen and Amsterdam have been building transportation infrastructure for the last 30 years that highlights bicycles, and car owners drive like there will be bicyclists there. During interviews in several videos there I've heard people remark that they ride bikes because it is easy, their relationship is based on comfort, not on fear:
Bicyclists waiting at an intersection, (note that there are no helmets).
Source: How Copenhagen Became a Cycling City, Niels Jensen, Planner, City of Copenhagen
If you make it easy to ride a bike, people will ride bikes. If you make it easy to drive a car, people will drive cars. In the US we currently devote most of our road works budget to making it easy to drive cars. This change is where safety really lies.
Stroller racks on a bus, New Zealand, 1950's
Do you find that this idea makes sense? If not, why?
I am sure that some people reading this will object that cars are necessary to keep our economy running, to which I reply that how many people bicycle and walk on a road is a good indicator of how safe they feel on that road. (see for example the links on this page: http://www.aviewfromthecyclepath.com/2008/08/pit-canaries.html ) This raises the bar from a material goods level, to a true quality of life issue. It is not good enough for a road to be rideable by young males with reflective protective gear on good equipment in good weather, it has to be comfortable for 99% of riders in regular clothes on average equipment in most weather. This is how you encourage people to ride. The true safety issue is not helmets, but quality of life and participation in health promoting activities.
Road markings in Australia
Moving your body is not a new idea:
"Excess eating of sweet and fatty foods, lack of exercise and excess of sleep causes obesity. There is impaired tissue metabolism leading to weakness and degeneration of tissues. There is a coating and obstruction of different channels in the body resulting in decreased supply of nutrients to tissues leading to death... exercise may be protective." Sushruta Samhita, 600 BC
This quote is from a Australian public health report conclusion that commuting on a bicycle is about the most beneficial exercise program possible, as it is active enough to trigger the body's healing responses, but not so active that it causes acute problems, it is easy on joints, and very importantly it is done regularly: http://safety.fhwa.dot.gov/ped_bike/docs/cyhealth.pdf
If helmets cause a 5% drop in ridership, then they truly are a safety factor, but in the wrong direction.
The summary at http://www.cycle-helmets.com/ of the tabling of Australia's national mandatory helmet law in 2013 sums it up. Particularly sad is the note that the number of children riding or walking to school went from 80% in 1977 to the current level of 5%, with the decline starting with the passage of the mandatory helmet law in 1991. The mandatory law contributed to Australia being the fattest nation on earth in a 2008 diabetes study.
This TED talk "Bicycling for Life" by Mark Martin at LSU looks at many of these points:
My current view of helmets and bike safety has become:
-Bike riding is one of the safest forms of transit, with the lowest fatality rate (both nationally and in my state), and a less severe injury rate, due mostly to a slower speed than other vehicles.
-The inherent safety of bikes does not mean it is Ok to ride mindlessly, all users of a road have a responsibility to drive safely.
-Bicycle helmets may or may not help in a crash, and may be of limited effectiveness because they are designed for very low speed impacts.. Bike helmets are not one of the main factors in injury severity, and Magical Powers should not be ascribed to them.
-Bicycle helmets do deter people from riding. Mandatory helmet laws have been shown to be a bad idea, and even voluntary public education helmet campaigns have caused loss of ridership. Because of this safety campaigns should not focus on helmets.
-Bike riding should be encouraged by public health agencies, because the benefits far outweigh the risks.
-Most importantly, safety campaigns are more effective when:
1. They are focused on separating fast moving vehicles from everyone else that uses the road (such as in Amsterdam and Copenhagen). Infrastructure is fail safe, and protects all riders regardless of their skill level.
2. They review rules of the road and proper bike usage (similar to Driver's Ed for car drivers)
Most of bike riding is common sense and similar to a car, such as if you ride at night, drunk, without a headlight and tail light, you are asking to die. A few other things that I've noticed with the cargo bike:
-My traveling speed is much too fast for a sidewalk, and I've also read that where sidewalks go across roads at intersections are a leading location for accidents, so I don't ride on sidewalks.
-On a motorcycle my preferred lane location is towards the right side of the left tire track, but this is not possible on a bike on the open road. However in downtown White River, Hanover, or even Hartland's two stop signs, I can keep up with traffic, and I ride in that lane location just like on my motorcycle, obeying all lights or traffic signs, and signaling. Drivers treat me like a motorcycle. (I should mention for people unfamiliar with these towns that there are no bike lanes.) Out of the center I ride over to the right.
A little bit of humor- Stephane Bertrand is riding safely over to the right
on this section of Russian steppe highway that is under construction,
and has red flags on his solar panels to warn other motorists.
Also note his helmet is safely protecting the headlight.
Photo credit: The Sun Trip, see link in the sidebar
-Bicyclists have a legal right to use the road- do not ride so far over to the right when the road is narrow and conditions aren't safe that it encourages car drivers to try to squeeze by you, drivers must pass safely. Vermont law is 3 feet minimum clearance with an additional foot for every 10 mph above 30 mph. On the other hand, the law also states that bicyclists traveling at less than normal traffic speed shall ride as far over to the right as safely possible. There are responsibilities both ways.
-Something new I've had to learn is Dooring:
The Door Zone, Source: Allston-Brighton Bikes
Ride a few feet away from parked cars- do not use the right side of the bike lane.
In properly designed streets like Amsterdam or Copenhagen, Dooring can't happen, cars are parked on a diagonal, or removed from the travel lane entirely. The separation also makes pedestrians safer. Infrastructure is the fail safe way the way to go, good infrastructure stops mistakes from turning into something worse. In my opinion (warning!) infrastructure is going to become more and more important, as we realize that roads are not just for cars.
My understanding of bicycle helmets now is that they offer limited protection, and a much better approach to safety is learning half a dozen to a dozen pointers about bike riding to actively avoid crashes in the first place. (Such as how to use left hand turn lanes, lane placement, watching for right or left turning cars, or dealing with right side merge lanes.) Next most important, I would like to see engineers and planners move away from spending most of the transportation budget on cars, and make it easier and more comfortable for most people to use bikes or walk.
Riding the solar electric cargo bike has been a blast, and drivers in my area have been great. In the last summer and fall only one driver passed so close that it bothered me, but that person was greatly outnumbered by several dozen drivers who actually waited for me at intersections or narrow parts of a road. On the bike I've gotten to say hello to many people I would have ignored if I was in a car, and it's been very rewarding. It just plain feels good. By all means if you are concerned about helmets then wear one, but don't make them a priority over good riding skills, and don't let them stop you from enjoying the far greater benefits of riding.
To be able to compare the bakfiets and the longtail, I've chosen a very good speedometer. The Cycle Analyst can be ordered with an external shunt and be used on any electric vehicle, but the model used on the Bakfiets was designed to interface directly with the motor controller, and has a 6 pin plug in. This uses the shunt inside the motor controller and should be pretty accurate, as the shunt value is specified by the factory to two decimal places. Unfortunately this CA is not able to use feedback from the motor hall sensor phase signals to determine speed, because the geared motor has a slip clutch built into the gear carrier that disconnects the motor from the tire. The CA installed on the bike needed to be equipped with an external sensor on the front wheel for measuring speed.
There is a wealth of performance information that is tracked, the easiest way to explain is to run through the screens:
Current Battery Voltage, Speed in mph, Current Watts energy use, and Miles traveled on trip
Same as first screen, but with Miles toggled to Amp hours
Total Watt hours used on trip, and Watt/hours per mile (this is similar to miles per gallon)
For motors that are direct drive- Regeneration electricity. The geared motor can not do regeneration, but a very tiny amount amount usually shows up, because when the motor is turned off the collapsing magnetic field inside it generates a back emf that feeds electricity backwards.
Same Regen screen as above, toggled to show Forward (normal direction) Amps
The minimum and maximum Amps, and minimum battery Voltage. Minimum Amps will go negative with regeneration. Maximum Amps is programmed to be 15, but I have decide not to change the shunt value to lower the Amax to 15, because it would reduce the Wh/mile below the 13.2 average, which is not likely to be correct. Volts minimum is how low the battery drops under a heavy load, and an older battery will drop more.
Maximum Speed, Average Trip Speed, and Elapsed Time for trip (total of any time the wheels are turning)
Number of Cycles and Total Amp hours drawn from battery, and Total Miles traveled since the memory was reset. LiFePO4 batteries have a 1500 to 3000 cycle lifetime depending on how hard they are used, and usually the battery dies from age instead of cycles.
This is pretty much all the information needed for the average cyclist, and even one using the speedometer for light training purposes. However since two separate bikes are being compared, it would be useful to compare the differences going up or down a hill, or cruising along flats. A data logger (Analogger) was added to the speedometer for a closer analysis.
To ensure correlation, GPS data is written alongside the Amp hours used, Volts, Amps, Speed and Distance. The data file looks like this (new values are written on a defined interval, currently about every second):
Ah V A S D
3.7861 40.35 0.00 0.00 11.183
3.7861 40.35 0.00 0.00 11.183
3.7861 40.35 0.00 0.00 11.183
3.7861 40.34 0.00 0.00 11.183
.......
The corresponding GPS-NMEA information is written out in 19 sentences for sequential locations. This gives data that should be a very close fit when comparing performance between the bakfiets with geared motor, and the longtail with direct drive motor with regeneration.
