Tag Archives: ebike

Electric Expectations – What to Expect from a Bike Friday Electric Assist System (BF EAS)

Design Goals At Bike Friday we start with the end goal in mind. Bicycles are already so special and refined it makes no sense to add things that do not add to or enhance the wonderful experience of cycling. We usually think of cycling as self-powered, so efficiency takes more thought than when designing powered things. Since electric assist is adding power the handling of this needs to be very careful so as not to destroy the magic and joy of the cycling experience. Our list of requirements is lightweight, quiet, unobtrusive to our cycling skills and to those around us also cycling. To make it better. The goal then is to make it possible for any cyclist to ride as a strong cyclist without a major downside.

Do you need an assist? – Ask your average capable cyclist and they will tell you, they do not need a motor. For over 40 years of my 50+ years of cycling, I would have said that also. Turns out it was because I was human, selfish, and ignorant. I was a strong cyclist. Being strong I have come to understand is to be able to ride at 15 to 17 mph without undue effort for an hour or two at a time. (24 to 27 kilometers per hour) The kind of speeds you would see on Cycle Oregon by those finishing each day in the middle of the finish times. (40 to 90 miles a day) This I found was my preferred commute speed also. For me that range optimizes travel time, cooling effect, ability to ride & talk with others & the safest speed with others on shared routes. (Bikeways to appropriate roads with light car traffic.) Turns out one of the most cycling experienced areas of the world also agrees. European electric assist laws allow motor assist to 25 kilometers per hour. If above that you must supply the power yourself. Or get licensed and insurance!

How much pedal assist is needed? – This can be pretty simple. The best way to measure human power is in watts. Average Humans on a bicycle are producing in the range of about 50-150 watts for 1 to 8 hrs. Tour de France heroes are not average. They can support from 200 to 300+ watts for many hours. They are working really hard to do so! Those 20-30 second 40 mph sprints at the end of the stages? About 1000 watts. World hour record, about 400 watts! Aerodynamics plays a huge role in your speed at 20 to 40 mph. The hour record was about 30 miles! The faster you go the more your power goes to the wind. Your important number.

How fast can you comfortably ride? That is your personal optimal wattage. Here is how to find that. Based on a 150 lb rider, on a well-fitting lightweight bike, with good tires on flat pavement. Can you ride 9-11 mph? You produce about 30-50 watts. That is 3 times faster than walking, making you the most efficient mover on the planet! 11-13mph? You produce 50-75 watts. 13-15 mph>75-100 watts. 15-17mph>100-125 watts. 16-18mph>125-150 watts. 18-20mph.>You are putting out about 150-200 watts, & for regular riding probably do not need an assist. But if the friends you regularly ride with do ride this fast &regularly drop you, some assist might enhance your experience as it is more enjoyable to be able to keep up. If people you ride with have trouble keeping up then some lightweight assist might be good for them! How about your spouse? Sound familiar?

So what does a Bike Friday Assist System look like? – Researching electric assist and electric bicycles can be quite confusing. A Bike Friday systems’ #1 goal is to get you into the 125-watt range or to the 25kph (15.5mph) speed if you are pulling a trailer, heavily loaded, or on a cargo bike with kids, or special hills and challenges on a route you struggle with.

That means you may need an extra assist of 25 to 100 watts plus the potential of maybe another 75watts in some conditions. Online research will see suggestions of 750-1000 watts needed. And many folks say you need a throttle. A throttle & over 500 watts means an electric motorbike! At best you would be assisting the motor. More likely your 50 watts are irrelevant & no need to pedal at all! Motors and batteries to achieve 1000 watts are large and heavy. Motors and batteries for Bike Friday assists are small & light. Adding typically only 10-11 lbs (5kilo) to your bike. On a typical Bike Friday assist, you can easily remove the wheel with the motor and put in a standard wheel when the assist is not needed or wanted. Same with the battery. Easy to take off when not wanted. There is no throttle in sight. In fact, no controls really. The system needs to be turned on like turning on a bike computer.

Your regular bike skills do everything else. When you start to pedal, the BF EAS adds the necessary watts you need to get to your goal. It does this while it seems to you that you are doing it. You are just feeling especially good today and strong! A Bike Friday with assist is typically well under 40 lbs and can be under 30 lbs. Typical Electric bicycles are over 50lbs. Even very expensive so-called light ones are in the 40s. The lightweight means they ride well even when the power is not on. It means they are lift-able. It means they are more useful and fun and easier to take with you.

In addition to being light & quiet, BF EAS is designed to be legal. – Most of the world where electric assist is popular have specific laws for them to be on the road as a bicycle rather than a motor vehicle. The core restraint is 25 kph maximum speed with an assist. Not surprising to find it is in my sweet spot above. Some laws talk about different wattage limits. Higher wattages can accelerate faster but the speed limits are usually similar. In the US we still have areas with no law, or they are illegal, or the laws have 20mph, 28mph, and 750-watt limits. Still the wild west. None of these will be problems for the BF EAS because its intention is just to assist you to be a strong cyclist and to be able to travel. One of the most difficult legal restraints for electric assist is traveling by air with them. The problem here is batteries and flight safety. Bike Friday systems are all available with airline legal certified batteries! And many packed Bike Fridays with assist will fit within the 50 lb weight limits for a minimal or free check on.

Control System

Design is personal. – why the use of an assist might be relevant for you. I have been a bicycle commuter, a sport rider, and a tourist most of my adult life. Cycling was core in raising my children, both in pulling them in a trailer and riding with them in tandem. I feel their confidence as adults and their connection with me has been much enhanced by raising them close to the concept of personal power that cycling has at its core. There are times looking back where a little assist would have made it so much better or have been essential if I was not such a strong cyclist. No wonder more haven’t found that child raising magic.  But they could with an assist!

A couple of years ago I started having issues with hips and a leg and for a time I wondered if I would need to give up cycling to work and give up my core exercise and social/ fitness outlet. I lucked out and was able to find the wonderful secret that appropriate assist was for me. What it has allowed me to do is continue to ride to work and back on a predictable schedule. Sometimes pulling a trailer that I need to get things from my home shop and back from Bike Friday Central. Some days I am better than others. The BF EAS allows me to dial in 25 watts or 100 watts or 150 watts. Whatever I need that day based on how I feel, how much I am carrying, & whatever the conditions. Because I can, I actually ride more & make more trips than I used to do, because I can add a bit of assist to bring me to that normal joyous sweet spot. My design is personal & I want the best for you also.

Best in Cycling,

Alan Scholz

The only Electric Bike you can travel with…

How to fly and with ease, bring your electric bike. LiGo Batteries are the only electric bike battery you can legally enter a plane with and Bike Friday was/is the first travel bike to employ them into the design.

The Battery: The LiGo by Grin Technology

Yes, these batteries really can be carried on passenger aircraft in carry-on luggage. Both we and our customers have clocked hundreds and hundreds of flights with LiGo batteries going through security without any incidents. Aaron, from Grin, even caught on video what happens when LiGo batteries go through the scanning belt. We recommend removing the LiGo packs from your baggage and plugging the pair of Anderson connectors on each pack into each other so that there are no exposed terminals and each pack is clearly individually contained. Airport personnel has been well trained at looking for the watt-hour rating lithium batteries and seeing if they are compliant or not.

While most airlines do not have a firmly defined maximum number of batteries under 100 Wh that can be brought aboard, we’d suggest traveling with no more than 4-5 LiGo’s per person in order to avoid extra scrutiny. Grin has had customers travel by air with as many as 12 LiGo modules on them, but we wouldn’t recommend that as a matter of course.

Travel with the LiGo powered E-Bike Friday:

Bike Friday E-Bike packed and ready for travel *photo: Ruth K.

Bike Friday E-Bike almost ready to ride *photo: Ruth K.

Bike Friday E-Bike ready to ride after being unpacked *photo: Ruth K.

Rear Hub Drive(our most popular system for NWT and Diamond Llama)

Motor replaces rear hub in the rear wheel.  This is a Bafang motor which has been tuned to perfectly work with our wheel size and bikes.  It’s the quietest system you can buy and is super smooth which you will love.

– This kit is compatible with all Bike Friday models –

This is the most popular system that we sell for our bikes! This system packs easily and pairs well with Ligo batteries making it the best option for travelers!


  • Is similar to the front hub motor kit but also has an 8,9,10 spd cassette driver. This allows it to work with all rear dérailleurs.
  • No motor resistance
  • Fits all 20” wheels (406mm & 451mm)
  • Very light! Adds only ~ 11 lbs to your bike
  • Ligo travel battery option makes for a light electric assist bike that is legal to fly with.
  • Very Quiet!
  • Easiest to pack into the suitcase for air travel.
  • Disc brake compatible


  • Rear frame dropouts on a bike need to be sized to 137mm – 140mm (wider than usual)

System price for Motor and Battery kit starts at $1320 (bike price not included)

Front Hub Drive:

Motor replaces front hub in the front wheel with a specially designed Bafang motor which is optimized for our wheel size, is the quietest you can buy and works effortlessly.  With this option, you are able to remove it when you want to lighten the overall bike weight depending on its use.

Front Wheel Electric Assist Kit with Ligo Travel Batteries on a Bike Friday New World Tourist Silk

– This kit is compatible with all Bike Friday models –


  • No motor resistance when coasting or riding without power
  • Fits both 20-inch wheel and 16-inch wheel Bike Fridays
  • LiGo travel battery upgrade option available (as seen in the picture above)
  • Comes standard with pedal assist
  • With a second front wheel and 3 minutes you can take off all but one lb of the weight (removing motor and battery) and have your light non-assisted bike ready to ride


  • Puts weight in front of the bike which isn’t natural to everyone.
  • Harder to control in slick or loose-dirt situations

System price for Motor and Battery kit starts at $1275  (bike price not included)

LiGo(the only travel-approved E-bike battery in the world) 3 Batteries and bag $525

LiGo 4 Batteries and bag $700

Charger: $49.00

Contact us and a bike design expert will help you with your questions and find the best electric kit for your situation.

For retrofitting older Bike Fridays into E-Bikes with an electric assist there are additional costs. Contact us for details.

Bonus Material: Walk assist on every Bike Friday E-bike which means stair assist. Life changing!

Running an Ebike on Solar Energy: The Sheddy Kilowatt Story

Five minutes after I installed a solar panel on the roof of my bike shed it began to rain. Since this was April in Oregon, the rain was not an unusual or unforeseen event and in fact, the next five days were rainy and mostly cloudy. But even on those damp days, my solar system managed to generate enough power to not only charge my e-bike, but also my phone, Android tablet, and radio batteries. After that first week, I knew that I had pieced together a workable system. It’s not fancy or particularly elegant, but it gets the job done.

Sparky, my eBike, runs off a 36 Volt, 12.5 AmpHour Lithium-ion battery Since Watts equal Volts times Amps, Sparky’s battery holds 450 WattHours of power. Sparky’s stock wall charger plugs into a U.S. standard 120 Volt AC outlet and puts out 42 Volts DC at 2 Amps so it puts out 84 Watts in an hour. To completely load Sparky up with 450 Watts takes about five and a half hours if I plug into the wall. Charging off the sun is a different story.

The hundred Watt solar panel I got from eBay only puts out 100 Watts in some theoretic, perfectly sunny world that I certainly don’t live in. And even if the panel were to miraculously put out 100 Watts, it would do so only at a maximum voltage of 18 Volts. I needed to get that up to a steady 42 Volts to charge Sparky.

My first thought was to get what is called a “boost controller.” This is a device which will take a variable voltage input (like what a solar panel puts out) and boosts it to a constant voltage. Like damn near everything these days, the Chinese make an inexpensive one you can buy on eBay, so I ordered one to go with my solar panel.

The controller uses advanced software algorithms initiative rope move, quickly and accurately tracking the maximum power point of photovoltaic panels module voltage, active tracking work at the maximum power point of the solar cell module in order to get more solar energy. Enhance the charging current and power generation.

After reading that I decided to initiate my own rope move and I went on YouTube and found some guy with a British accent who had messed around enough with one of these controllers to figure it out and explain it in such a way that even a dumb American like me could use it. Following his instructions, I set up my boost controller put out the 42 volts I needed to charge Sparky’s battery.

While that system worked, the flaw in my plan quickly became apparent, I had to have Sparky parked in the shed and plugged in to get the power off the panel. The panel doesn’t generate power at night and in most of the daylight hours, Sparky is at work with me. While I could just charge Sparky using the main power at work and have my employer pay the power bill, that is not at all what I wanted to do. I want to run Sparky on sunshine.

Sir Robert Watson-Watt, the inventor of radar, once said: “you get one idea today, you get a better idea tomorrow, and the best idea…never.” My next idea was to add an intermediate storage battery to the system and as I researched and thought my next, next better idea was to get a little integrated battery/inverter Power Bank unit. I found a good one, again made by the Chinese and available on eBay.

The device is marvelously complicated and came with a manual that had obviously been translated into English by a not too bright robot. Here is an actual paragraph from that manual:

“The controller uses advanced software algorithms initiative rope move, quickly and accurately tracking the maximum power point of photovoltaic panels module voltage, active tracking work at the maximum power point of the solar cell module in order to get more solar energy. Enhance the charging current and power generation.”

I also got a little recording Watt meter which is not needed for the system to work, but useful in that it tells me how much power the panel is generating and how much has been stored. The Power Bank has a little 4 LED power meter but the Watt meter gives me a clearer picture of what is going on.

The Power Bank has built-in circuitry that lets it take power straight off the solar panel, so I no longer need to use the green boost converter. The solar power, up to 220 WattHours, gets stored in the Power Bank’s internal Li-ion battery. The Power Bank charges up during the day while Sparky and I are at work.

You might have noticed that the Power Bank has roughly half the capacity that Sparky does. That means that if I came home at the end of the day with Sparky completely depleted, even if the Power Bank was fully charged, I could only charge Sparky’s battery half way. If that actually happened, I’d need a second day to charge the Power Bank and then transfer that power to Sparky. In practice, I’m a pretty frugal e-bike rider and in a week of commuting and errands, I only use a few hundred Watts.

My typical charging pattern looks like this: I get home Friday night and Sparky is down to around 50%. I plug Sparky’s standard wall charger into one of the 120 VAC inverter outlets on the Power Bank. The next morning, Sparky is full and the Power Bank is empty. I spend the weekend riding Sparky around and the Power Bank spends the weekend in the shed charging up. Sunday night I again connect Sparky to the now full Power Bank. Monday morning the Power Bank is again depleted and Sparky is ready to take on the work week at full strength.

The actual truth of things is that even with less than great weather and the inefficiencies of various intermediate batteries and inverters, my little solar system gives me more than enough power to keep Sparky humming along. In fact, I have more than enough power so I also use the power bank to keep my phone, tablet, and radio charged up. All the words and pictures in this post come are here thanks to solar power.

If you want to build a system like mine, the only two parts you really need are a Solar Panel and a Power Bank. The prices of these things tend to fluctuate. I paid about $100 for my 100 Watt panel and $131 for my Power Bank. I consider it money well spent.

Keep ’em rolling,

Kent Peterson
Eugene, Oregon

E-motion is High at Bike Friday

E-motion is High at Bike Friday

The 3 Es of our Electric Enhancement systems for Cyclists

E-xpectations, E-tiquette, E-mancipation


why now? the law, realistic power & speed, + flying with an E-nhanced BikeFriday

Why now?

Why now and not before? The short answer is confusion. Confusion caused by multiple definitions of what an electric bike is. Many widely varying opinions of what they should be, laws all over the world about electric bikes that do not seem to have anything in common with each other and sometimes with bicycles. Equipment has become a lot better and (tops for me) quieter. And last working through my own unfounded it seems large biased against electric assist. – Here is an example. – Depending on where you are in the world the local laws allow 200 watts, 250 watts, 500 watts, 750 watts, and 1000 watts motors. All being defined to fit under the classification of regular bicycles because they have pedals!

Electric bikes and the law(s!)

Are they talking about the same thing!?

I think bike laws have had a huge share of confusion. In a big part from an obvious appearance that they were not written by folks who understand bicycles or cyclists. The local laws that allow 200 watts, 250 watts, 500 watts, 750 watts, and 1000 watts motors to all being defined to fit under the classification of regular bicycles, because they have pedals. The average person pedaling puts out about 60 to 100 watts. This will get you from 9 to 14 miles an hour on a flat road depending on your bike and your position. Add another 100 watts to that will put you at 20 mph. Something that fit riders can do. Or you can do with a 100 watts system added to your own 100 watts. Some jurisdictions have speed limits of 15mph(25 kph), some have 19mph, some have 20mph, some have 22mph and even 25, 28 and 30mph! A long read on Wikipedia on electric bike laws will convince you they do not share rational with regular cyclists. Some laws limit your speed if you have a motor to less than you could ride on your own without! Some tie the law to helmet laws, or to age required, 14, 15, 16 years old and older to ride them. Some areas just make them illegal. All the laws are trying to distinguish electric bikes so they don’t need to be licensed like a motorcycle or moped. The most rational laws are the European Union one and how the Scandinavian countries treat them. But even those don’t specify if the power limit is motor wattage draw or output power. (Most systems only average about 70% efficient, so a 200 watts system could be actually 200 watts output or only 140 watts.

A realist interpretation of the law for power and speed for a Cyclist

Perspective makes it all fall into place – and in your favor!

At Bike Friday we believe that looking at it from the perspective of a cyclist will keep you from conflicting with the law almost everywhere. A basic interpretation for the reason for a law is to make sure we play well together without endangering each other and to limit the damage to ourselves. Or even simpler, that common sense is not very common. So to put it into perspective a few rules of thumb can make the size of things much clearer. –

It takes about 60 watts to walk at a steady manageable pace. (3mph/5kph) A jog at 6mph/10kph is about 75 to 100 watts. It is easier to cycle than to walk and the same outputs give you about 3 times the speed. ( with air drag starting to dominate going over about 10mph). A relatively healthy and fit person can ride at 100watts for quite a few hours (longer than they can jog because no jarring) and with that go about 13 mph. (producing an 8 hour century, if you are fit enough in the nether regions.) Average city cycling speed in Copenhagen is about 10 mph/16kph. So that is base perspective. Strong fit younger riders are flitting around town at 15 to 17 mph and putting in some effort. A decent amateur cyclist can produce 200 watts for many hours and with that ride at 20 mph. 20 mph and overtakes special handling skills. Racers develop this but not good for the average person without the experience, willingness, and skill to crash relatively damage free. (As long as cars are not involved. Oh! They are!) (Best in the world can do 400 watts for 1 hour! With a special position on their bike & go 30 mph). Our bike club here in Eugene has determined that speeds over 15 mph on the bike paths is dangerous to everyone. Physics also says the same thing. With these insights, your goals and expectations as a cyclist become clear if your goal is to ride with others and keep up with folks a bit stronger than you. The sweet spot, and confirmed by my own 50 years of cycling, is 15 to 17 mph. This says the European laws make the most sense, 25 kph /16 mph. If you can do that without electric enhancement you don’t really need it. And if you can only ride at 75watts or 50 watts you only need about another 60 watts to ride at 25 kph /16 mph. That means 200 to 250 watt motor (at an average of 70% efficiency) will bring you to at least 200 watts total and ability on the flats to ride 20 mph. It is clear that unless you have powered cycling in mind (not pedaling at all and at relatively dangerous speeds without a shell around you for protection) you do not need a horsepower (750 watts) or 1000 watts plus to be an E-enhanced cyclist of above-average ability! Nothing wrong with having a hobby but cycling for most of us fits under 20mph on the level. (tailwinds are free game! Watch the downhills.)

Flying with an Electric Enhanced Bike Friday is now possible!

Simple, light and legal batteries can fly with you

Bike Friday was an early pioneer in making it easier to travel and fly with a bicycle. We did that by making the bike fit the airlines’ regulations. One of the bugaboos of Electric bikes or Lithium batteries-anything is that it is still a fast developing field and some of the first steps in really high power batteries were more dangerous than expected and scared folks. Especially the FAA. None of us wants fires on planes and because of the numerous battery chemistries and manufactures the rules are very stringent. The solution to this at BikeFriday was to innovate by looking at their requirements and finding someone who could help us meet them handily. ( If you read the piece above this you can probably guess that Bike Fridays electric enhanced are lighter & more efficient bicycles do not need huge batteries and still get a significant range.) We did find a great company and product to make the whole system work and fly legally. The solution is very sophisticated & durable modular batteries that meet the FAA’s criteria & when joined up to make a light & effective battery for your traveling Friday. Typical batteries add about 4 lbs to your carry on luggage. (3 modules for 300 watts hours capacity)


Sharing the cycling space, noise, you can keep up but you shouldn’t make others suffer or be unsafe.

How are Cyclist different and what experience & space belongs to them

I doubt that if you are a cyclist reading this that I need to tell you that we are not motor vehicles but a type of pedestrian. (the best type!) Our drive is human scale interaction with minimum gear and maximum fun. Where ever we ride we are looking for it being quiet enough for us to converse while we ride and no noxious fumes or dangerous fast-moving metal. We want it to be quiet and we want to feel like we are supplying all the motivating force. Good manners mean we respect that for others so that we all get the great reputation that arriving by bike gets almost everywhere.

Keeping up is great to do – Dropping others you came to tide with is a no-no

I have ridden with thousands of people over 10s of thousands of miles. From that, I pull an empirical perception of cyclist both new and old timers. One of the core ones is this. People want to keep up but other, perceived faster stronger riders (not always true), intimidate them even to the point of them apologizing and asking others to not wait up for them. So when you arrive with a big motor they may not be comfortable and may think or say you are cheating. I will cover the false idea of cheating below but it is very bad manners to go on a group ride with the intended or unintended results of dropping others who the pace is too fast for. With a light, quiet, simple Bike Friday E-enhancement equipped bike, good manners and good logic says you use it to keep up but not challenge others with it. I have found my riding E-enhanced with the groups is well tolerated. I seldom tho when using it see the front of the group and only then if I am sure I will not pull too hard so as to drop someone. I also feel if I am comfortable I am the right guy to slow down and ride with anyone who drops off the pace. Turns out they are often better company than the fast guys!

The Essence of cycling is elegant, non-obtrusive, human scale, at one w/ nature & companions.

Seems like that says it all there. If your electric enhancement improves or helps ensure that for you then it is cycling. If it doesn’t then it is probably fitting another description.


the truth will set you free, a tailwind when you need it, put it all together. E-motion

An Egalitarian perspective. The perspective from eyeglasses.

It took me a long time to confront my bias but eventually, I realized that electric assist can be seen as like an eyeglasses prescription, what is needed to bring my sight/riding as close to 20/20 as I can.

Being a strong rider does not mean we need to ignore empathy and yet I do see that often in young riders in their exuberance. What I am espousing here is the good that can come from sipping a few electrons so that you can continue to fully participate. If you can ride at 150 watts all day then you may not need help. (I also sometimes use mine to ride with the 200 watts crowd) The point is that the sweet spot of about 14-17 mph 23-27kph should be easily and properly available no matter your current engine. You can tell them Alan Scholz told you it was OK!

Simple, Freeing, & Easily available

When you put it all together, a properly designed, simple, light, quiet/silent E-enhancement is little different than padded cycling shorts, a great saddle, or a mentor on a tandem taking you on the first group ride that you kept up on. It can be all the difference towards understanding why cyclist keeps on keeping on with the smile on their face, the bugs in their teeth, and the weary good feeling in their legs. (ok eating is a good reason too) When you consider all the large costs in the world for minor returns the Bicycle comes up as one of the great deals of all time. A few electrons may be needed but don’t be shy, they may be all you need to stay in and there is plenty for this.

That’s what emancipation is. It is a right.

E-motion is the operative word and can have a fine double meaning.

At Bike Friday I am pleased to be able to help level the playing field. I did not for the longest time realize was tilted in my favor. Pulling a trailer with kids, a loaded cargo bike is a couple of great reasons to add a few watts to the average human to make transportation rational and elegant, but maybe this is the reason that folks who really love cycling don’t understand why others don’t find it exhilarating. Maybe you need to ride in the sweet spot feeling like it is all you!

Alan Scholz – CEO & CO-FOUNDER & Bike Designer

May 2018