FREQUENTLY ASKED QUESTIONS
1) Does the electric bike vibrate like a gasoline-powered bike?
No, it does not. The first thing riders notice is the silence and the lack of vibration (followed by the low center of gravity or balance point). You can see in the mirrors as they are not shaking and your hands do not become numb from vibration.
2) Do the bikes make any noise?
The bike is almost silent. Hard throttle applications produce a low growl for a short distance off the line. After this, the bike is mostly silent except for the sound of the tires on the pavement and the sound of the electric motor soft whiring.
You do not hear the racket of the chain and belt drives like on Brammo or Zero bikes or the high rpm sound of their motors. The hub motors on our bikes turn 80% less rpm than the Brammo and Zero motors at the same vehicle speeds, so they are far less noisy and much more durable (and require no maintenance) At a stop the bike is completely silent. Freely talk to your friends at the stoplight.
3) How much less expensive is it to run electricity instead of gasoline?
>>>>>>CHARTS AND GRAPHS AND FORMULAS<<<<<
5) How hard is the bike to drive?
Easier than a conventional motorcycle. All of the controls are hand controls and their is no clutch. Additionally the very low center of gravity, created by the having the hub motor and batteries below the axle line, makes the bikes easy to handle in parking lots. The seat height is much lower than most motorcycles.
Motors and Performance
4) Why do the ZEV bikes have so much more torque and speed than other motors of the same watt rating?
Because our motors have a large diameter and are multiphase with major emphasis on motor cooling. A large diameter motor has more torque for acceleration and hill climbing than smaller diameter motors at the same amps/volts. This is because the output torque quadruples when the motor diameter is doubled. The larger diameter of our motor means a tremendous increase in output torque.
As a motor begins to heat up, it loses efficiency and power. A hot motor runs slower and with less output power than a colder one. This is why you see such a huge difference between the peak power ratings and the continuous power ratings used by some manufacturers.
Vectrix advertised a maximum torque of 65 Nm,
but only 23 Nm continuous. To compare, even the 50% less
expensive ZEV3600 has 139 Nm continuous.
An ZEV standard motor in a 72, or 84 volt bike has 185 Nm of
The ZEV way is to use a motor far more capable than its rated power; use every possible engineering trick to make it run cool; then run it at a lower amperage so that it stays cool, efficient, and steady. A more thermally efficient motor wastes less input power, yields a higher continuous torque, and lives longer. A large motor running at low load yields a more efficient motor that lasts longer. You can spot the less powerful smaller diameter motors easily. Using a same 13 inch size wheel as an example, look at the bolt circle on the outside of the motor cover to show the OD of the motor. The ZEV motor is on the left filling up the wheel to the rim. The much smaller motor of the competition is on the right.
The problem for other hub motors is that because of the small motor diameter, the motor must run high amps to the motor to get the torque we get at lower amps. But losses due to resistance are equal to the motor current (amps) squared x resistance. The inherent problem with increasing current is that an electric motor is basically a resistor, and the heat generated by a resistor increases with the square of current. Double the current, and you've got four times the heat to dissipate; triple the current, and you've got nine times the heat. That's why heat buildup is a major limiting factor in bike motor designs. By having to run higher amps because of their motor design, smaller hub motors suffer far greater losses in range, speed, and total efficiency. This problem also appears in the designs of bikes with chain or belt drive like ZERO and Brammo where they must run small diameter motors to get them into the bike frame and still have room for battery. Some of these bikes run 400 amps to get less than 1/2 of the torque of the ZEV.
Additionally, we have special oil cooling in all of the high
power motors that is exclusive to ZEV. Bike motors are rated by
watts. The failure mode in brushless motors is usually due to
heat. Often that means the magnets come loose in the motor or wiring
burns out or hall sensors fail. You can quickly spot the difference in our motor over all
others. The large number of stainless bolts and the distinctive cooling
fins make our motors instantly visible different to any other motor on the
market. Winding resistance is a major factor in motor selection because it
seriously affects the motor constant (Km). Winding resistance and motor current
produce power loss in the form of heat and motor temperature rise. These
losses directly degrade motor efficiency.
Most motor windings are copper wire which has a positive temperature coefficient. A winding temperature rise from 25 to 155°C increases wire resistance as much as 50%. Likewise, a proportional decrease in resistance occurs for temperature drops. The competition suffers greatly from these heat induced losses. It is common to see heat losses of 50% of power in smaller hub motors.
We use the expensive rare-earth neodymium-iron-boron magnets to get the maximum power from our motors.The controllers also must be cooled. ZEV controllers are covered in deep cooling fins.The more powerful the bike, the more fins on the controller. ZEV controllers must hold a minimum of 24 hours of full power.
All of this attention to cooling is not just about power. It is about durability. The better the cooling the longer the parts last. That is why we can warranty bikes for two years. Lowering the temperature of electronic components can double and triple operating life.
5) Explain the problem of corrosion in motors and how your oil bath stops this?
Many motors have cast aluminum housings. The metal
is not treated for corrosion. So after a short time they look like this.
This white coating that forms from corrosion on the aluminum parts is just part of the problem. A rust also forms on the magnets. As the clearance in the motor is usually 1 mm or less, the motor becomes a grinder for the small particles of rust and aluminum oxide dragging down the motor. The white aluminum oxide coating acts as a heat barrier causing motors to run hotter. Hot motors do not last as long as cooler ones and put out less power.
ZEV motor parts are treated to stop this corrosion and the heat problems that go with it. The oil bath in our hub motors keeps the parts coated in oil so that corrosion does not occur while cooling and lubricating the parts.
6) Is getting water on the electric hub motor or controller a big worry? Will it short out?
ZEV models use a sealed hub motor and controller. In comparison, none of the Chinese electric vehicle companies have a sealed motor. Our products have a double seal at the axle and a seal around the motor housing, so riding in the rain or on a rain soaked street is not a problem.
However, ZEV are not off road bikes, meant to be used for running through the mud or into salt water. Driving the bike into water that is deep enough to flow into the front air inlet or sides and wash over the battery terminals will cause potentially catastrophic damage, the electrical equivalent of water in a gas tank.
7) What is the "Soft Response" option that is available for the high power bikes?
The standard bikes are sporting in nature, meaning they are tuned to accelerate hard. Some riders prefer a softer throttle response. This option dampens the throttle response and the acceleration about 20% and in actual driving, stretches the bike range a little. For those customers mostly interested in range, this is a good option.
8) How long does it take to charge a ZEV bike battery?
A lithium battery ZEV can absorb about a 75% charge in only about 25 minutes. Generally, two hours of normal charger usage is required to top off the battery. Four hours of charging is required if the battery is depleted. (Batteries should not be used to total depletion, otherwise damage can occur.)
Silicone (lead plate) batteries must be charged over a longer period of time than a lithium battery. 6 hours total charging time should be allowed.
The best battery life can be obtained by charging after every use. Running the battery to depletion and then charging shortens its life. Charging at 70-75% depletion instead of 80% depletion increases the battery life by 50% according to the battery supplier. Lithium and lead acid batteries can be charged whenever possible regardless of the charge left.
Charging with a 220 v charger takes on average 1/2 the time than with a 120 volt charger. Installing a 220 volt outlet and ordering a 220 v charger will give you far shorter charging periods.
9) How do you know when you need to charge the battery?
On every ZEV there is a battery power meter on the instrument panel. This meter reads acts like your fuel gauge. The instrument panel also features a volt meter informing you of the total voltage available to the motor as it declines during a long ride.
To further warn that you are running low on power, there is a speed step-down feature in the controller. Once the voltage is significantly depleted, the internal computer steps down the power to limit the maximum speed, thereby providing a gentle reminder to start thinking about a recharge.
Your ZEV should also be charged monthly even when not being driven.
10) What brands of battery do you use and why?
We use two types of battery, GBSystems Lithium and the GreenSaver silicone battery. (The GreenSaver battery is unique among lead based battery in that it is not acid, it is alkaline. It does not sulfate and go bad like an acid battery. It also maintains its power at sub-zero temperatures.) While there are many other brands on the market, these two are the best to use for several primary reasons. These batteries are the most proven and widely-used batteries in electric bikes in the world. Because of the huge number of vehicles that use these batteries, the battery sizing has become standard so other companies have conformed to fit this standard.
Furthermore, unlike companies that use 190+ tiny batteries linked together like TESLA Motors or use a unique battery pack like ZERO or Brammo, there will be a supply available when you finally need a battery replacement. Even in the apocalyptic scenario that ZEV is not able to supply our customers with replacement battery packs, the customer will be able to procure new batteries for themselves. You do not even need to buy it from ZEV.
11) How long do the lithium batteries last?
According to the manufacturer, the batteries will last for over 3000 full cycles in general usage. The less depleted a battery is when it is charged, the more cycles will be obtained. In daily use, a battery is generally not run down to near depletion, so the cycle life is high.
We use the GBSystems battery in our lithium models with a Battery Management System (BMS) that mounts on top of each battery to protect the entire battery pack. This photo shows the 4 bolt per terminal connection featured on all our models that offers radically more protection from connection loosening over normal 1 bolt per terminal battery connections.
12) Do you have trouble with battery cooling or battery fires?
We have never had a battery fire.
We do not have hot battery problems because of our emphasis on cooling all parts of the system. To prevent any battery problems due to heat we use batteries that are in finned cases for heat shedding. These fins additionally prevent the batteries from fitting against each other creating cooling passages between the batteries that align with cooling passages in the battery mounting tray.
Handling, Storage, & Frame
13) How is it possible that you get the claimed handling out of scooter-sized wheels compared to a motorcycle?
First of all, there is little difference in the diameter of the tire mounted on the wheel. Many motorcycles run 16 inch wheels. Racing-type bikes like the Honda CBR600RR or the Kawasaki ZX10 run 17 inch wheels. However, the diameter gets you no advantage. Consider that 17 inch wheels are used on 140-160 mph motorcycles: larger OD wheels run less rpm for a given speed. That makes the forces on the tire less at blinding speeds. Our tire OD is in keeping with our max design speed for our scooter line of 110 mph.
The big difference is in the tire cross section on the road. A Honda CBR600RR sport bike runs a 120/70 front tire. Our ZEV bikes run a 130/60. Our scooter tire is wider than the sport bike tire for more tire contact with the road and has a shorter, stiffer sidewall for less tire squirm in the turns and during hard braking. For hard braking or hard down in a curve, the tire contact patch size is the big factor along with how much grip and force can the tire transfer to the road. Just how big and fat our tire is can best be realized in this photo.
Our batteries are mounted low in the chassis with the battery mass down at axle level. This radically effects braking as the bike wants to stay level or squat slightly in "panic stop" braking without lifting the rear wheel. This allows you to have big brakes on both wheels. It is the contact with the ground by two tires that gives the most braking, not the rear tire doing hardly anything and the front tire at the verge of skidding.
A good illustration is to compare the ZEV 7100LR to the Brammo Empulse with its illogical layout of the battery raised far above the axles and a small rear brake with very large front brakes to balance this layout. The braking force is all trying to go through the front tire contact patch - which is smaller than that of the ZEV tire. The ZERO has the same mass location as a Brammo and a narrow front tire. During hard braking, if these top-heavy bikes can get enough traction to the front tire, it will lift the rear wheel causing your back tire to break loose.
14) How much storage space is available?There is a luggage rack on the back of most ZEV models. A luggage box is available for that rack. Under the seat is another compartment on most models (not the 7100 LR or any T-series model). Two coats are shown in this space in the photo below. This space will also hold a half helmet.
There is a large hook below the handlebars on which you can hang grocery bags or a carrying case/handbag. This hook can be used as a bungie cord attachment point to carry large packages on the floorboards.
15) How do you protect the frame from corrosion?
Our frames are first cleaned by shot blasting, and then
submerged in a plating tank. Next, they are coated with an extremely
durable paint coating and the coating baked onto the frame.
16) The bikes look big. Are they easy for a small person to ride or anyone to handle?
Yes, they are extremely easy to ride. The reason is
that there is no motor or engine weight above the axle line. All of the
weight of the motor is inside the wheel. The batteries are in the extreme
bottom of the bike below the axle line. This means that the effective
weight of the bike is only about 8 inches off of the ground. There is
also no gasoline weight mounted high to cause balance problems. Further, the seat height are in the range of 3-4 inches lower than most motorcycles, or about 28 inches.
17) You talk about "Rider Safety" features. What are those features?
ZEV bikes brake better than any other street production bike on the road in their weight class. No bragging, just fact.
>>>BRAKING DATA CHART<<<<
Insurance industry studies have shown that dual headlights and tail lights have radically better recognition by car drivers and dramatically assist in distance judgment. Therefore, All ZEV models feature dual headlights. All ZEV in addition have an extremely bright, LED blue-ish daytime running light that stands out in traffic.
The standard ZEV have headlight bulbs in their dual tail lights for "pay attention car driver" effect that can be seen quickly. [CUT PHOTO COMMENTS]
They also have dual lights on the front and a 3rd LED center light to draw the eye.
Additionally, the overall weight is very low. Compare the ZEV5000 or ZEV6100 to the slower (and radically more expensive) Vectrix. The ZEV is 200 lbs lighter for a bike that is virtually the identical wheelbase. >>>CHANGE REFERENCE<<<
18) You refer many times to standards for your testing. What is a SAE standard day and a standard man weight?
An SAE standard day is 59.9 degrees F, zero humidity, at sea level, barometer measurement of 29.9 inches. These do affect an electric motor as they relate to the cooling of the motor. The more heat in a motor, the more resistance in its windings and the less output it makes. Colder and denser air allow for better cooling.
We test our motors at 150 degrees C (~350 F). Then the measured power rating of our motor is listed as the continuous power maximum that can be held with the motor heated at that level (150 degree C). This testing standard produces a motor that is underrated in comparison with that of other companies.
The standard man is 165 lbs.
Repairs & Parts
19) Does an electric vehicle need any maintenance?
Of course. Weekly, tire pressure should be monitored and provided with compressed air as necessary. Monthly, check all axle bolts, brake caliper bolts, and swingarm bolts to ensure they are still tight. Yearly, check the front forks’ head bearings and the battery terminal block connections for corrosion and clean as necessary.
However, that is far less than a conventional motorcycle. There are no fluids to change and no chain to oil.
20) I realize that there are very few parts in the bike. Are replacement parts expensive?
Compared to a gasoline vehicle, the parts are very inexpensive. Using the example of our 4100 watt bike: $650 for an entire new motor, $15 for a throttle, $550 for a controller. The replacement cost for batteries in 2014 is $1840 for the lithium batteries for a 6100. All of these parts are easily exchanged by an owner with only a few tools. No high amount of technical skill is required.
21) How hard is it to replace a controller or motor?
That will depend on the individual replacing the components. Our ZEV bikes are designed with quick change components to keep repair costs down.
Directly under the luggage box is a junction box. Removing the cover on the box gives instant access to the connectors for the controller. The controller is held onto the bike by 4 bolts. Unsnap the connectors, take out the 4 screws and the controller can be swapped out.
With the junction box exposed, 5 bolts will remove the rear wheel motor.
Allow 30 minutes or more to change either component.
22) Is it correct that you sell all of the parts of your vehicles to racers and people that want to build some exotic vehicle or a racer?
We encourage racing using our components. We at ZEV believe that racing improves our products and the industry as a whole. The racers and builders feedback is invaluable to us. Our company also has a racing sponsorship program where a buyer can earn back 5% of his purchase price just by going to the track and running. Technical service is available to racers along with information on modifying bikes for more power output.
23) Are the ZEV bikes fully compliant with the USA NHTSA and EPA requirements to be fully road legal?
ZEV is a USA manufacturer with a USA VIN number. We do not suffer the problems of the ban on Chinese motor scooters with the VIN sequence starting with an L. Our bikes are also compliant with EEC requirements.
24) How can I tell if a bike is legal to register and drive in the USA?
By law every bike on the road must have:
- A label showing verifying that it is NHTSA compliant. This label must match a specific configuration required by law.
- A label showing that it meets all EPA requirements.
WARNING: Many manufacturers and consumers believe that because a vehicle is electric it does not have to meet EPA requirements. That is not true. The law says that all vehicles must meet the EPA requirements.
Many of the importers of Chinese vehicles state to their customers that the vehicles are legal when in fact they are not. On the NHTSA website, there is an announcement about 3,000 bikes being seized as illegal and 200,000 more seized or blocked. The Pennsylvania Department of Transportation (PENNDOT) placed a ban on all Chinese motor cycles and scooters in November 2008.
Do not take the chance your new bike will not be allowed on the streets. Purchase from a company with a USA VIN number or demand strict proof that the company has filed all NHTSA and EPA documentation and registered with both agencies. Further, make sure that the Certificate of Origin is of a form and quality acceptable to your State Agencies. Several brands of Chinese bikes are trouble-prone because the documents used to obtain their titles are not as required by NHTSA/DOT.
25) How can I tell the difference between a real ZEV and Chinese knockoff copies?
There are a number of easy ways that even an untrained eye can detect:
- Look for the plastic covers on the swingarm or the plastic fake exhaust. Absolute Chinese giveaway.
- Ask the company to show you their models for 7,000, 8000, or 10,000 watts of motor output power or to see a 72 volt bike with 60 Ah battery installation of 5 Kwh capacity. Their frames are not the same as our special frames and cannot hold the battery volume.
- Ask the company to show you their oil bath motor.
- Ask if they have a daylight-running headlight that complies with USA law. We know of no made in China bike that is legal to drive because it does not have this on light.
- Ask to see the EPA and DOT compliance labels with the stamped in VIN number that must be on the bikes to be legally sold in the USA.
- Ask if they have a 3 or 4 speed electronic transmission controller. Only ZEV has this.
- Ask to see their 70, 80, or 90 mph bikes. Only ZEV has these.
- Look at the brakes. Do they have dual piston calipers on front and the rear?
- Do they have the large OD front disk for more swept area like the ZEV?
- Is the luggage rack black like all ZEV? Chinese bikes tend to have silver luggage racks.
- Do they have the 100 mph speedometer of the ZEV?
- Request a copy of their Manufacturer's Certificate of Origin. If it does not have the manufacturer as Z Electric Vehicle on it, then it is a fake.
- Ask for what the VIN number is on the bike you want to buy. If it does not say 1Z9, it is not ours. If it says L or X as the first number, it is clearly made in China.
- Look at the motor to see if it is the very high bolt count, black, modular motor, with cooling fins like our motors.