EnerTrac Corporation Electric Hub Motor

Update: See EnerTrac’s limited time offer at the end of this post.

In order to understand the beauty of electric motorcycles you need to look beyond the silence, ease of maintenance and lack of emissions. Electric motors have only one moving part, the rotor inside the motor. They are small and powerful and becoming more so every year. So why should the motor have to sit in the motorcycle frame attached to the wheel by a power robbing chain coated with the slick stuff electric motors are supposed to eliminate?

Mark Gelbien and his company EnerTrac Corporation believes the motor belongs in the wheel itself. Mark has developed a turn key electric motorcycle solution called the EnerTrac Hub Motor. The MHM-602 model is a 3rd generation version of the motor that will fit any swing arm with a minimum 7.5 inch gap. Most gaps are larger so it is centered with shims supplied by EnerTrac. Each time a customer purchases a wheel to fit in their donor bike EnerTrac has never fitted it’s motor to, Mark will engineer a plate to attach the rear brake disk to the hub motor and any other mounting hardware needed. This is included in the price. For more information on the technical specs take a look at the EnerTrac specifications page.

I had the pleasure of chatting with Mark and his son at the AMA TTXGP eGrandPrix at Vintage Motorcycle Days. After showing some interest in their product they asked if I wanted to ride it. I’m sure my eyes turned into saucers as I ran for my gear while saying “heck yeah”. I had just seen Jeremiah Johnson sail quietly down the straight at Mid Ohio at 80 mph so I knew this is not a test ride I could pass up.

After a quick spin around the Mid Ohio grounds I understand why Mark is so excited about his product. The motor had more power than I could use in the busy roads around Mid Ohio. Acceleration was more than adaquet for daily riding. I never exceeded 30 mph before needing to hit the regen (more on that later) but given the linear power delivery of all electric motors I doubt the acceleration fades too much as speeds increase. With this in mind, merging onto freeways and keeping up with your friends stinkies on Sunday morning rides should not be an issue.

The feel of electric acceleration was both familiar and new. Most of us have been on an electric train. The ones that put you on the ground if you don’t hold on? Constant, linear acceleration from the Enertrac motor moves the bike forward with what starts as a growl and fades to a familiar electric hum and wind noise. Throttle response is great but you feel a very slight pulse in power delivery off stand still when starting out slowly. Apparently this is called “cogging” as I found out in Kraig Schultz recent review of the bikes at eGrandPrix. Nothing annoying or dangerous, it is very consistant, predictable and subtle. An interesting trait of the motor.

As I eluded to earlier, the Enertrac hub motor is capable of regenerative braking (aka “Regen”). Mark’s Lifan LF200 conversion was set up to take advantage of the feature. “Regen” turns the electric motor into a power generator that will charge the batteries as you decelerate. 10% of the regen was activated by hitting the rear brake. The other 90% was variably dialed up with a thumb throttle on the left hand grip. The setup is a bit complicated but remember, this bike has no clutch or gears to worry about. Within a few minutes I had the system down and could engage 100% regen while grabbing the front brake for additional stopping power.

When engaging the regen at 100% I could stop faster than I would normally stop coming up to an intersection. One question I asked was, “Can I lock up the back wheel with regen?” Mark informed me that if the wheel stops, no regen forces can be generated so the wheel will never stop turning from this feature.

There are some drawbacks to the EnerTrac hub. It is heavier than a conventional hub and it is all sprung weight far from the center of gravity of the bike. Usually this is the last place you want to add weight as it will affect acceleration and handling. This did not stop Jay Johnson from hitting speeds over 80 mph and some universities have approached Mark about using the motor in their 2010 TTXGP entries so this does not seem to be a big concern.  Also, the benefits of regen braking on a motorcycle is a controversial one. Many argue you do not generate enough power to justify the weight and complexity it adds. However, the feature is optional so you be the judge.

The bottom line is the EnerTrac hub is a simple, elegant solution to making your motorcycle electric. If you want to build an electric motorcycle and love simplicity or don’t want to deal with cutting and fabricating a motorcycle frame to mount an electric motor it it is a great solution. EnerTrac has a large waiting list for the $1295 motors so if you want one give them a shout asap.

Update: Mark sent me this limited time offer from EnerTrac if you purchase a MHM-602 or MHM-603 :

You can send EnerTrac your rear swingarm and EnerTrac will mount the wheel in the swingarm space it out correctly, mount your rear disc rotors and also space in correctly for your caliper. I am offering this service free, for a limited time.

EnerTrac can do additional value added work such as design, machine and install a proper bracket to mount a rear brake caliper, install the tire and whatever additional work is needed to have the hub motor wheel work correctly. Price based on time and material.

Of course, always free technical support to our customers

Thanks

Mark

EnerTrac Corp.

Source: Enertrac Corporation