When it comes to electric-assist bikes, there are different ways of controlling the motor’s power. This is today’s subject. Pedelec is a term that loosely defines the way an E-bike’s motor is allowed to assist the rider. It generally means that the motor will only operate when the rider is actually pedaling the bike. Some like this, while others will want to be able to use the motor’s power anytime they decide its needed.
When buying your new electric motor powered bike, it is up to you to choose the type of control system you want. With so many makers of E-bikes, each with their own control system, you need to investigate, test, and decide which is right for you. I will start with the simplest, and work up to the most sophisticated.
The E-bikes that my wife and I own are E-Zips. They are the least expensive and simplest electric bikes on the market. If you have viewed my multi-part series of articles on them here, then you are quite familiar with this bike. (If not, now would be a good time.) This power system has been offered as a conversion kit for 10 (?) years. With a twist throttle, you are in full control of the motor’s action. It does have a switch on the throttle housing that converts it to the action of a pedelec. Let me explain a little how that works, and why.
On the bottom bracket (pedals), there is a Hall Sensor. It sends an electric signal to the motor’s control unit to let it know if the pedals are turning. The switch has two modes. One is TAG, that means twist and go. The other is PAS, that means pedal assist. I think you get the meaning. Regardless of which mode you are in, the twist throttle is the only way to make the motor power up. Personally, I like this type of system very much.
This brings up the question why all E-bikes aren’t just like this. One reason is that it is not always the most efficient way to control the power. To get maximum range from your battery, you don’t want to just use the power from the motor without adding your own leg power to the mix. Also, you need to hold, (and vary) the throttle all the time you want the power assist. Some cyclists don’t like the thought and feel of this motorcycle type of riding. They want some assist, but controlled automatically to match their power input.
One thing I like about this type of control system is that it allows me to add a little power as I first start from a stop. That makes riding safer and more comfortable. Also, I know when the motor is giving full power on hills, because I am in control of it. Once again, not as efficient, but I like the feel of it. The next system I am covering is a full-time pedelec with a thumb throttle (twist or thumb throttle, they both do the same thing, only with a different motion–another option to consider) to add power when you need it. Similar, but a little different, I see this on e-Motos, EZ-Pedalers, and eZee bikes.
On some of those bikes, the dual control system is optional. I personally would make sure I got the dual control option. Also, make sure the bike has safety motor cut-off switches in at least one of the brake levers. With some pedelecs, the motor will kick in when you are slowing, and using the pedals to effect a downshift. Not generally a dangerous thing, but it does tend to get your attention. The motor cut-off switch in the brake will help you eliminate this, and save the bike from using your battery power unwisely.
On many of this style of systems, there is one more control for power output. It could be a multi-stage push button system, or a rotating knob. The power comes on the moment the control box senses the pedal movement, and the extra control is what tells the motor how strongly to assist. Like a throttle, but preset with a knob or button. This is there to help the efficient use of your available battery power, I don’t care much for this system, as when you need to change it, it will require looking, moving your hand to the control, and making the adjustment. That is too slow, time-consuming, and potentially dangerous for my liking.
The most advanced systems are on the Gepida Reptila 1100 and the Sanyo Eneloop. They could also be on other E-bikes, but these are the two I am familiar with and have ridden. Both are very nice, with smooth, automatic power assist. They both have an adjustment for total amount of assist, mostly in the name of efficiency, but also for maximum assist on hills and in the wind. They use a very advanced sensor to know how hard you are pedaling, and add the motor’s power to match your output.
The Sanyo has a complicated magnetic sensor system in the bottom bracket, and the Gepida has a sensor that measures axle torque at the rear wheel. Match this with the accompanied electronics, and you have a system that is great when working, but troublesome when on the fritz. Ah, modern technology, great when all is well, but a nightmare when not. Still, a fantastic way to control a E-bike, and definitely the future of all E-bikes to come.
So there you go. I hope this makes this E-bike thing a little easier to understand. A true pedelec will only add power when you pedal, and the others will give you the option of adding power when you like. As much I like the advanced feel of the Sanyo and the Gepida, I love the simplicity of my E-Zip. Of all the E-bikes I have ridden and tested, I think the system on the e-Moto Liberty 1.5 is the best for most riders. Smooth, powerful, and with both types of control. Make your choice, it’s up to you to get the electric-assist bike of your dreams.
Happy Biking, Turbo Bob.
“There was a time when bicycle riding caused such a furor in America that it threatened the country’s economy. Shoemakers were sitting idle because they claimed that hardly anyone walked anymore. Barbers complained that men were so eager to ride bicycles that they often skipped a day’s shaving. At a time when a pair of shoes cost three dollars, a good suit of men’s clothing fifteen dollars, and a dozen eggs were fourteen cents, people were rushing to spend over a hundred dollars on a bicycle.”—Gordon S. Leete.
Rent or buy a E-bike in San Diego http://iselectricbikecenter.com