Electric Bikes - Introduction
The objective of this web page is:
(a) to bridge the gap between classic bike riders who look down on e-bikes (sort of like sailboats vs motorboat snobbery)
(b) to open up biking to people who have tried classic bike riding and find the hills (or their knees) defeat them.
Quick read: In 2011 we began our research, buying pre-made ebikes and then, when we concluded they were overpriced and underwhelming we shifted to kits. We bought ten different kits... various front hub and rear hubs, and then in January 2013, whilst visiting the Bafang Factory in Suzhou, we were invited to try a new mid-mount prototype, the BBS01. Where ebikes had been evolving, this was a revolutionary change, a great leap forward, and we asked to buy a couple. The 250W and 350W units were made in March and we began testing them in April, writing up our findings in the enthusiasts forums. We then put together a buying group and bought 27 motors, and in doing so changed ebiking on our home base in Waiheke Island. A new ebike store opened up, tourists starting coming over and renting bikes, then after a day of falling in love, buying them. In our hilly island, ebikes became a common sight on the island. The point of all this? In 2015, our recommendations are simple. Buy the Bafang BBS01 or if you live in a country that allows more powerful motors, the BBS02. Put it on your existing bike, or buy the nicest city bike you can find. The photo above is a new Pashley Princess with a new 300W BBS01. This week the bike shop is installing a new BBS01 on a 1950 BSA bicycle that is being restored mechanically, but with the hand-applied green paint that is traditional. If you want an ebike, that's the way to go in 2015.
Finding a great classic bike (classic meaning the time-tested design for slow cycling) is hard enough. Then once that part is sorted, one tries to get good information about putting a reasonable motor on the bike to flatten the hills, and it gets even more confusing. This page will contain just enough technical stuff so the non-engineer can understand what is involved, and to make it easy for now, it then provides a few recommendations on what to buy at a reasonable price. There are many other options out there, but until we have tested them, we cannot speak intelligently. This page will change as we try new products and experience them in real life.
In looking for an e-bike advice on the Internet can be confusing, as many of the enthusiasts are representative of a minority that is into speed, electrical engineering as a hobby, and the e-bike as a passion rather than a form of transport and pleasure. When a writer talks about a 40 kph/ 25 mph bike that can get up to 65 kph / 40 mph, they are not talking about the same machine as a recreational hill-flattener (a nice bike that uses a motor to make riding up hills more pleasant), they are talking about making a bike into a moped or even a motorbike. On this web site, devoted to slow cycling, it is unlikely our readers are looking for the ultimate in speed and power.
The first thing to do is evaluate your conditions.
Flatlanders: If it's really flat, like in Cambridge (GB), Berlin (DE), Lecce (IT) or any city that is flat and lacks stiff winds forget buying a motor unless you have bad knees, a pedal bike is all you need... one speed or three speed. In the top part of the photo to the right, a Bella Ciao is outfitted for Germany. Used first in the glorious bike city of Berlin, then with one pannier and a front bag, on a five day flat ride along the Elbe River from Dresden to Prague. No motor needed, the three-speed Shimano hub was perfect. Then it came back to Auckland... where it was at grave risk of rusting in the shed, due to the killer hill outside our place... you go nowhere unless to go up that hill first.
Hills and valleys: If you have some hills, limited distances of a few miles each way, and are looking for a recreational way to enjoy biking in which you pedal most of the way and use the motor to make the pedaling fun, not painful or dead-slow, then a 250 - 350W* front motor attached to a classic bike of your choice is the way to go. Provided it is wound for torque, not speed, it will boost you up a fairly-steep, not-to-long hill with reasonable peddling - your legs will get a workout, but not scream in pain.
In this first photo, the same Bella Ciao from Berlin first was fitted with a MXUS front motor. The controller and all the extra-length wires are in the front bag, which is an old fashioned Brooks bag. It worked but it was noisy and it is a one-speed system.
In March 2013, we received a prototype of the new Bafang mid motor BBS01. We removed the front MXUS motor and installed the Bafang. Love it. Quiet, subtle, uses the gears. It made this site a lot simpler. Forget hub motors. Mid-mount motors that drive the chain are the only way to go. Among other things, the controller is built in. That may not mean much, but with an external controller, it is one more thing to get right, and it means a bunch of extra cables, any one of which can fail and leave you with no assist.
So, in December 2013, we put together a buying group of folks on Waiheke Island and ordered 27 BBS01 motors. They arrived in February 2014 and we had a big install day. So far, no problems with any of them. It's a winner.
To put this in perspective, you can buy a single-speed Bella Ciao in Germany (or UK) for €800 (about US$1,000 - 1,100 depending on the exchange rate; add €100 for the Shimano 3-speed hub). This includes a 19% VAT tax that can be refunded if you have the right paperwork and exit the EU. The Bafang kit with the 36v battery costs about US$1000, plus shipping and duty from China to your home country. So for about US$2,000 (not including taxes if they apply), you get a classic bike of exceptional quality with one of the best batteries in the business, an excellent controller and a good, lightweight motor. Of course, at this time, you also have to add a round-trip ticket to Europe to collect the bike, and then spend a couple weeks riding from one great cafe to another along the best bicycle routes in the world. In New Zealand, we recommend the Pashley, since there is a dealer in Christchurch and we have sent him motor kits that are now with very happy customers.
Note however, that this is a do-it-yourself approach. If you want a bike shop to put it all together, you will have to pay for it. If you want someone to handle all the details so you get a turn-key solution, remember that people need to earn a living, and no one gets rich in the bike business even when it is doing great. A US$2,000 price is probably comparable to a US$4,000 price at the local bike store, except that right now the local bike stores don't carry the right products (which is why we saw it necessary to create this web site).
And of course you don't need to travel to Germany. Almost any bike with a standard bottom bracket will work (35mm x 68mm) because the motor clamps in using its own braced locking nuts, not the bottom bracket threads. We even salvaged a 60 year old Raleigh DL-1 that was doomed for the scrap yard by using a hacksaw to cut the 75mm bottom bracket to about 68mm.
The Kit: To make a bike into an ebike, a normal bike can be used. It needs
- battery and charger - Typically 36 volt. We find 36 volt to be the best for slow cycles. You can go with the BBS-02/48V 500-750W motor in the USA, but you won't get much exercise.
- controller - this is a historical comment. It's a sealed box with lots of connectors for the battery, motor, throttle, brake-cut off, cruise control, on-off switch, speed limiter, etc) (built-in with the Bafang BBS01)
- motor with built-in controller- in kits we are now sold on the mid motor that drives the front crank so gears can be used, like in a car.
- accessories - throttle to make it go, multi-speed to give 50%, 75% or 100% power, cruise control (lock on), brake handles with cut-off sensors, etc.
Battery: The battery can cost as much as, or sometimes more than, the rest of the motor kit. Whatever you do, do not buy a cheap lead-acid battery and avoid bikes that offer this. Cheap, but too heavy and does not last. Cheap=cheap. One of the big advantages of buying a kit system is not being locked in when the battery wears out. If you buy a premade ebike, when (not if) the battery needs replacement, the cost can be very high because you are a captive audience. Also, battery technology is changing rapidly. The odds are that when your battery wears out, there will be something better, lighter and more powerful when its time to replace it.
Warning: Do not mess around with batteries. Buy the charger that the vendor recommends for the battery and do not charge the battery with anything else. Vendors match their chargers and set up the BMS (battery management system) so you do not need to worry. If you have multiple chargers for different batteries, make sure they have different-shaped connectors so you cannot accidentally hook up the wrong charger.
Don't overbuy: More Ah means the battery runs longer; it's like a bigger gas tank. Don't buy more Ah than you need because it costs more to buy and adds weight. If you take trips into the village for coffee, an 8Ah battery may be sufficient. If you plan to ride all over town, you may need 11 Ah or more. Remember, you can always carry your charger with you and plug in for a charge - just check how long it takes to recharge - the times vary considerably. You also can buy two small batteries and only take the second one along when you know you have longer travel coming up. If you want to learn more about batteries, go to Battery University.
Quick Tutorial - How battery numbers work: Most bike batteries are made of cells. The A123 cell, for example, is rated at 3.6 volts and it lasts 2.3 aH (amp hours) and each one weighs 70g plus the connectors to join them. To get higher voltage the cells are stacked in series, to get longer lasting aH you add more series (i.e. put them in parallel). So a 39 volt A123 battery that is rated 2.3 aH will be 12 stacked cells. If you to get to 11.5 aH, you need five of those stacks (5 x 2.3 aH), meaning 60 batteries that are wired up by the maker and then hooked up to a battery management system (so you don't kill them through abuse). The battery maker also adds a power plug and a charging plug. The whole kit is then wrapped, usually in waterproof plastic, and optionally is then installed into some sort of metal can.
If you go shorter distances, you can buy a four stack 39v 9.2 aH and you will only be buying 48 cells, thus saving you money and weight. In our experience, it makes some good sense to buy two smaller batteries, let's say 3 stack each, meaning made of 36 cells to give you 6.9 aH to head out from home, and a second 6.9 aH battery to switch over to get back home when the first one runs out of juice. This way, if all things are equal (and they never are), you should make it home on battery power. This approach also allows you to only use the second pack when you take longer trips (but be sure to rotate the batteries, so they get use). It also gives you an option in the event a battery fails.
If you want a more powerful motor, you increase voltage by adding more cells to the stack. If you go from 12 to 16, your voltage jumps from 39 to 52 volts. This means the bike will go faster, provided you move from a 36 volt controller to a 48 volt controller. If you are wondering why 52 volts when talking about 48, don't worry, electric motors have ranges. In short, more volts means more power (a bigger engine), more Ah means longer distance (a bigger gas tank). We started with the big 52v 11.2 aH, but we sold it and now are using the 39v 6.9 aH which cost half the price and serves our purposes. We are thinking of buying a second 39v 6.9 aH battery to extend range on the less frequent times when we go on the longer distance rides. Pack it when you need it (but rotate the batteries so they get equal use). Here are several samples of the A123 battery choices.
- 39v 6.9 aH 36 cells [3x12] (local, lower speeds limited distance).
- 39v 9.2 aH 48 cells [4x12] (medium range, lower speeds)
- 39v 11.2 aH 60 cells [5x12] (all day around town, lower speeds longer distance).
- 52v 6.9 aH 48 cells [3x16] (local , higher speeds, limited distances)
- 52v 9.2 aH 64 cells [4x16] (medium range, higher speeds)
- 52v 11.2 aH 80 cells [5x16] (all day around town, higher speeds, longer distances)
An Englishman in China: Paul lives in Shanghai and he has a small business selling mostly MAC motors and batteries that he makes up himself. His web site is http://em3ev.com/store/ and he combines the best of East and West. China makes millions of ebike motors, so their prices are low and their quality is getting better every day. Paul selects reliable products, speaks English as his native tongue and understands when customers need advice. His prices are slightly higher than the Chinese bulk houses, but our experience has suggested the extra is well worth it. When we were in China we visited his operation and were impressed.
Premade E-Bikes: If instead you want a premade ebike there are many offerings... some good, some cheap components, an amazing range of prices and awfully expensive to experiment compared with the price of conventional bikes. The big problem with premade is that most of the bike frames and components are not that great. They are more like the big-box store bikes. Some look like kids bikes with their small wheels, not understanding the comfort and pleasure of 700c rims. Others are stretched to fit the battery behind the seat post. Some use shock absorbers rather than better designed steel forks that have inherent shock absorbency. They also can add 10kg (20 lbs) to the weight because they don't pay attention to details.
If you are not on a budget, buy a German-made Kalkhoff, which the pundits say is the "BMW of ebikes", priced accordingly. Kalkhoff has distributors in various countries. Their bikes use the crank motor and the newest has some nice features about it.
The advantage of a premade e-bike sold by a dealer is that any problem is the dealer's problem, not yours. Premade are generally designed as a system, so they should work well together. Our primary complaint so far is that most premade bikes are closer to the moped end than the fine piece of classic bicycle craft that epitomises slow cycling. Nothing wrong with that, but we are waiting for the bike that rides like and is built as well as our 1950's Raleigh DL (or our 2012 Bella Ciao or other equivalent Eurobike) that is designed with a riding-assist motor that is as invisible as possible.
No matter where you are the best approach is to take the various offerings for test drives, educate yourself about the various components, and decide how long you want your investment to last.
Unfortunately, ebikes are a bit like PC’s and digital cameras, where obsolescence comes fast. If you want a “keeper”, our advice buy an excellent 3-speed (or even one speed) bike and then buy a mid-motor kit that lets you keep the original wheels and brakes. By the time the battery dies there will be better technology, and if you try to sell the whole ebike, you may not see much of a return. If the bike is a keeper, then you just upgrade the motor, battery and controller to that future technology.
There is not a single solution. Much advice on the Internet is written by "e-heads", meaning folks who have gone off the deep end in pursuit of extremes. Some of their bikes look like an erector set with wires and batteries all over the place, using the aesthetics of duct tape - but they are fast! Also, the bike industry offers many style choices and some are a bit silly, like the teen who tarts his car up to look like a track racer to go shopping at the mall. Mountain bikes are all the rage, but they are made to ride in rough conditions off-road. Street racers give you a view of the pavement to cut wind resistance. Folding bikes are generally a compromise with most looking like overgrown kids bikes. Now carbon fiber is coming into its own, and you can buy Chinese frames for several hundred dollars... caveat emptor.
However, on this web site, the bias is for the classic English, Dutch, German, Nordic or Italian bike (aka Euro-city-bike)– designed for urban use. They give you a high profile to see and be seen. If you have hills too challenging, add a simple, bolt-on motor kit, and you will fall in love with bicycles once again.
* A note on Wattage: Europe and Australia restricts ebike motors to 250W, New Zealand 300W, and in America it seems to vary - up to 750W. However, two 350 W motors will perform differently. In fact, it is the controller that determines the power output, where the motor is more a question of potential. This is perhaps due to motors being rated by marketeers not engineers. There are many variables, including windings, fets, battery voltage and how the motor is installed. A motor that drives the crank allows gears, so going uphill it can work like a motor in your car. However, a motor that drives the crank is not a simple bolt-on. It is more typically found in factory made ebikes not add ons.
At present the whole industry is very confusing, and it is equally unclear what the police do to enforce the law. In the case of a crash, one can expect the motor will be tested, and if it exceeds the law, you will be prosecuted for an illegal vehicle as well as all the other damage or injury you cause. If a rider is seen passing cars at speed, the police may presume its a 1,000 watt 72 volt ebike and make an arrest for driving a moped without registration and required safety equipment. Word on the street is that to determine wattage on a traffic stop, the police look at the sticker on the motor. At this point, its a bit like the wild west. The rules are sometimes not well written, enforcement is confusing, and common sense is probably the best way to go. If you want to be certain you are safely within the law, buy a European certified e-bike. It may still give test output greater than the law permits, but the courts may allow that you acted prudently in relying on official EU certification.
If you join the ebike culture, please do not push the envelope so the bureaucrats ruin it for the rest of us. All it will take is a few headlines (idiot bike rider with 6,000 watt motor runs over toddler at 60mph) for overly restrictive rules to come into place. For now, a low-power electric motor requires no registration, inspection, fees or any of the other bureaucracy of motorbikes and cars. The cost to charge a battery is pennies per mile. The experience makes biking fun again and it is interesting to see how slow-cyclists gradually reduce the power as their legs get stronger and they prefer to do more human power and less volt-cycling.