Protean to Begin Producing Electric Wheel Motors

Thanks to $84 million in funds invested by GSR Ventures along with New Times Group and Oak Investment Partners, Protean Electric will finally be able to start manufacturing its much talked about in-wheel electric motors.

The production facility, located in Liyang, in the Chinese province of Jiangsu, provides Protean with access to the world’s current single largest automobile market, in which sales reached more than 18.5 million units last year.

“GSR is honored to lead this round of investment in a disruptive technology that we believe has great promise for the Chinese automotive market and potentially building a global EV platform,” said Sonny Wu, GSR Ventures managing director.

Protean’s in-wheel system has been designed to add gasoline hybrid and pure electric drive options for existing vehicles by providing a much lower cost and far more straightforward conversion process. In fact company CEO Bob Purcell has said “the Protean Electric drive system is probably as close as the industry will ever get to a bolt-on solution.”

So far the company has demonstrated its technology on a variety of vehicles, including a Ford F-150 pickup, Brabus based EV and hybrids (based on the Mercedes-Benz E-Class) and Volvo C30 coupe.

Although the facility in Liyang will only be able to handle fairly modest production levels (at least initially) and Protean still has to explore avenues for licensing its technology to larger customers, the recent investment certainly represents a significant step in the right direction.

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  • perfectapproach

    Makes me wonder how they compare in the “unsprung weight” arena to standard-drive wheels. Also makes me wonder if they are hardy enough to withstand the vibration of rough terrain at high speed.

  • AP

    perfectapproach, as an automotive engineer, I have the same concerns. The motors would have to be very light, very high torque, and very rugged. Plus very cheap, in order to put multiple motors on a vehicle.

    If you have a motor design that is that good, why not use just one that is about the size of one of these, spin it faster, gear it down (to multiply torque), and drive through axles, like other manufacturers do now?

  • Al Bunzel

    @AP, @perfectapproach, you raise interesting points about hub motor vs non hub motor.

    I’m still trying to figure out where the friction brakes are.

    Some of the benefits of hub motors are:
    * You don’t have to worry about a differential so there’s a weight and space saving there;
    * Each wheel can be individually controlled which opens up many new opportunities;
    * If you want, you can make a skid steer system (if all wheels have this hub motor) which could be useful in reducing the turning circle of a car;
    * You free up a lot of space in what used to be the engine bay (if going for an electric only set up) which can influence future car designs;
    * It becomes easier to make many models or variants of cars without increasing overheads significantly. Why? Because the same Electric Motor hardware & set up can be deployed in cars of different widths, lengths and shapes quite easily. With no differential, you don’t have to worry about different width drive shafts that come out of the differential. In terms of length, with no propeller shaft, it makes it easy to make a stretch limo. (I realize front engine front wheel drive or rear engine rear wheel drive cars don’t have a propeller shaft.) You can have the same platform with a different body, a bit like the skate board concept. It helps with common platform designs.
    * Allows more room for more batteries;
    * Car companies can save on drive shafts and propeller shafts;
    * Car companies can save on transmissions; and
    * Car companies can provide more interior room as there is not engine to compete for space.

    Some of the disadvantages of hub motors are:
    * Software gets more complex;
    * Unsprung weight increases (as perfectapproach pointed out) which could have an effect on ride and handling;
    * How reliable is it in rough terrain (again as perfectapproach pointed out)?
    * What happens if a wheel becomes out of balance – will it damage the hub motor?
    * What happens if you drive across a shallow river crossing or it is submersed in water like when going down a boat ramp to load or unload a boat?
    * What mechanical disengage mechanism is available should it be required in an emergency? and
    * Suspension settings will have to be revised significantly.

    I know someone who is doing a diy Electric Car Conversion using two Emrax AC Motors ( They are very small, yet high output. I think it is less than 4″ in length and less than 10″ in diameter. Each motor has a mass of 26.4lbs. He is looking to drive the wheels via a toothed pulley set up from motor shaft to drive shaft on his Citroen to gear it down. That way, he does not have to worry about unsprung weight, no worries about differentials etc.

    Personally, I would like to see hub motor technology used in more EVs because it saves space and I don’t have to worry about differentials, drive shafts, CV joints and transmissions. I look forward when Protean makes a kit for diy Electric Car Conversions.

  • Lemonlime

    If they could combine the wheel and the motor hub housing (wheel “is” motor, rather than motor “in” wheel), the unsprung weight could be reduced. Also, with regenerative braking, the need for friction brakes is reduced or completely removed. With the weight of brake rotors/calipers and axles removed, the motor should’nt make it too heavy.

  • Al Bunzel


    Your idea is worth considering. It is like the outrunner brushless DC motors (
    where the outer casing has the magnets and the outer casing is the thing that turns. The stator windings is stationary and inside (but that will still contribute to the unsprung weight).

    I guess one could strategically glue permanent magnets to the rim and by having the rim as the “can”, that is where weight savings can be achieved.

    Perhaps, also, carbon fiber components could be used in various places to help reduce weight. I’ve seen racing motorcycle rims from the TTXGP championship made from carbon fiber.

    I personally would still want to have rotors & calipers for my piece of mind.

    Keep the ideas flowing – this is good.

  • Steve T.

    wow…we are going to be soooo faaaarr behind the power curve for hybrid car interface that China is going to make us look stupid. Protean gets it. China gets it. Our auto makers still don’t get it.

  • cyberpine

    We don’t want to re-invent the wheel.. wait, that’s actually what we need to do. Is anybody surprised China want’s a piece of this action? What lobby or special interest group is working hard to make sure our legislators keep this technology out of US markets for as long as possible?

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