Sorry about the delay, but here is an account of my test ride of the ZEV models 6100, 7000 and the Trail and Utility 5100. The manufacturers web site is: http://www.zelectricvehicle.com/
The test site was at the Greene County Airport, near Waynesburg, Pennsylvania, a little less than an hour drive south of Pittsburgh. The final assembly is done in a small hanger at this typical sparsely used 3500 foot rural county airport. Upon arrival Darus Zehrbach, ZEV's owner and his helper (don't recall his name) were assembling the battery pack on a 5100 model. The following summarizes my impressions from observing talking to Mr. Zehrbach, observing the scooter being assembled, and the test rides.
Z Electric Vehicle Corporation
ZEV is a small US enterprise based in Morgantown, West Virginia and nearby Waynesburg, Pennsylvania. The principal officer and engineer of the company, Darus Zehrback has a background mostly various aviation-related enterprises including, he said, contract work for US military R&D. I asked him why he decided to get into the electric scooter line of business and the motivations of his buyers so far. He said that it was the low “fuel” cost and reliability of electric-versus IC engine powered cycles that were the main selling points. He elaborated a bit on maintenance costs of motorcycles, claiming that high performance motorcycles typically need valve overhauls every 3000 miles (?). I asked if concern about global warming was a motivation for many buyers, as it was for me whn I bought my e-maxs 5 years ago. Both Darus and his assistant pooh-poohed global warming (“by the time global warming becomes a problem you will be long dead” said his assistant). This seemed odd – an EV manufacturer who is practically a global-warming denialist. But I’m starting to digress. On to the scooters themselves...
The ZEV scooters are, externally, a common Chinese-style scooter with electric versions like the E-Fun, X-treme, R Martin and others. Darus said that the controller, motor, BMS and other key components, while made in China, are custom units made to his specifications. He said the frame is entirely his design and built off site (in China?) using jigs be designed and built himself. Final assembly is in the Waynesburg hanger, so the scooters have a US Manufacturer code (1Z9)on the VIN.
The battery pack consists of 40AH Thundersky cells, assembled in 4-cell (12V nominal) sub-packs then wired together. The 5100 I observed had five sub-packs (60V) the 6100 has six sub-packs (72V) and the 7000 has seven sub-packs (28 cells-84 volts). In the case of the 5100 they are mounted, terminal-up, and in a single row in a battery box mounted low in the frame. I assume the higher-voltage models have some of the sub-packs stacked, but overall, the battery packs appeared to be easily accessible for servicing. The BMS utilizes small shunt circuit boards across each cell and a separate logic module. The wiring that I could see was tidy and well secured. All the scooters used the 40AH cells. Only the 5100 trail I test rode used the larger 60AH cells.
Charging is done using an off-board 10 amp charger.
Instrumentation included a voltmeter for the 12 volt accessory system (not a particularly useful thing) a 1-2-3 LCD indicator for the “transmission” (more on that later), and a battery pack state of charge indicator that appeared (from its behavior during the ride) to be just a qualitative high-low voltmeter. So, as a bare minimum, the owner of one of these scooters would need to add a digital batter pack voltmeter (as I did with my E-Maxs) in order to provide even a crude qualitative state-of-charge indication. While technically US-made, the speedo and odo reads in kph/kilometers. The scooters use ordinary mechanical-drive speedometers, while the trail scooter uses an electronic digital speedometer with a magnet and hall pickup on the front wheel. Darus admitted the speedometer indication is probably high, claiming that this is the case in all motorcycles. I had hoped to verify the speed with a GPS, but couldn’t find a suitable attachment point.
The test rides were all limited to near-straight runs up and down the 3500 foot taxiway and slower riding on the ramp area. No rides were allowed on actual roads, due to insurance reasons and also, the demonstrator scooters were not licensed. This was a shame, since there are a lot of hilly and winding roads around the airport. Weather was cloudy, some light wet snow/sleet showers, damp to wet pavement and a temperature of about 2 to 3C. The runway and parallel taxiway is numbered 9/18 (straight east-west) and slopes at about 1% to the east. There was a 15 to occasionally 20 mph (25-32 kph) wind out of the west.
The Model 6100 was tested first. It felt quite light in weight – lighter than even my e-max, although this was probably an illusion of the larger size and lower center of gravity. The front brake emitted an awful grinding noise, as if the brake pads had worn to the point of metal-against metal. I decided to give it a test ride anyway, and reserve any critique of the brakes for the Model 7000. All scooters were given at least two speed-runs in each direction down the taxiway in the wind and slope conditions described above. Results:
6100 (claimed 101-102 kph)
Downwind/downslope 102 kph
Upwind/upslope 80-82 kph
7000 (claimed 130 kph
Downwind/downslope 120-125 kph
Upwind/upslope 100-105 kph
Note that these were indicated speeds on the speedometer. If they are typical Chinese scooter speedometers, they may be up to 10% high.
I also test rode the 5100 trail, but relying on memory, I cannot recall what the top speed except that it was indicating just below the claimed speed.
Other general observations and impressions:
- The acceleration of all the models is ample, but not outstanding - a bit better than my upgraded 60 volt E-max from 0 to 60 kph. The speed was still very gradually increasing at the end of the 3500 foot (1.1 km) speed runs.
- The brakes on the 7000 were adequate but basically had that “cheap-Chinese” feel - not entirely smooth and confidence inspiring. Brake effort was higher than it should be, like my e-max gets when the brake pads get worn and glazed, or when a new brake pad set hasn’t broken-in yet.
- I didn’t attempt much in the way of quick turns due to the damp conditions, but both scooters seemed to be a bit slow getting them rolled into turn. Maybe I’m spoiled by my little short wheelbase E-max, but it may be that the low battery pack placement puts the center of gravity too low and makes the scooter “too stable”.
- The throttle action was a bit “twitchy” on the 6100 and unacceptably twitchy on the 7000 where it would jump from off to perhaps 30% power no matter how gradually the throttle was turned, (and no matter what “gear” it was in). This made low speed maneuvering and parking unpleasant. Doing slow figure-8’s could be only done with jerking and lurching. It would be hard to pass the figure-8 test for the state motorcycle license on it without a lot or practice. I commented about this to Darus, suggesting a faulty throttle or controller adjustment, but he just said that it was an unavoidable aspect of “all that power” the scooter has. He said his 1000 cc Kawasaki does the same thing. Yeah, sure.
- The battery pack meter was sagging considerably during the speed runs. The 6100 down to 50% and the 7000 read down near the bottom of the gauge. Darus claimed both scooters were fully charged. This may be due to the voltage sag that Thundersky cells are prone to in cold weather. The 3-year old 40 AH Thundersky cells, with about 12,000 km of use on my e-max, sag down to about 2.8 volts per cell at 95 amps in recent 0 to-3C weather.
- The E-Fun style body of these scooters is not my favorite esthetically, but compared to my little e-max, it was more comfortable and practical. The fairings and even that that little windshield fended off the cold wind quite well and in spite of not being dressed very warmly, I hardly noticed the cold conditions.
There was considerable talk about the 3-speed “transmission” in a previous thread. The “transmission” is toggled 1-2-3-2-1 by a button next to the throttle handle (where the start button would be on a gas scooter) and on the 7000 automatically returns to “first gear” if brought to a complete stop. The effect of the “gears” seemed to have a different action on the different scooters. On the 6100, it affected the acceleration moderately and the top speed greatly, perhaps 45 kph in first, 70 in second, and maximum speed in third. On the 7100, it has what seemed to be just a slight effect on either acceleration or speed in either gear. Darus confirmed that the “transmission” is just a controller current and/or voltage limit setting – similar to the “90 second turbo” buttons on the old e-max. I'm feeling charitable, so I won't entirely dismiss this "transmission" as a gimmick. Such measures can be useful in providing the rider with “throttle discipline” for maximizing the range of the battery pack in various riding conditions.
Overall, my impression of these scooters was one of an 80% design in need of a few significant tweaks. Darus said that there have been some improvements - particularly suspension improvements, since they built these demonstrator scooters.
I’m limited in what other comparisons I can make, since my own experience on scooters or motorcycles of any sort is very limited. Ride quality was certainly improved over my e-max, commensurate with the higher speed they could safely go, but they still had much of the same Chinese-quality ride, finish, and component-quality as the E-max.