Z-BIKE WORLD
STORY
STORY

Z-BIKE

Z-Bike is an e-bike born in the Swiss Ticino Canton (Swiss Alps) specifically designed for our mountain territory, and it differentiates from  other electric bicycles in that: it has great autonomy; its high power, high performance motor with greater torque available uphill and marvelous handling. The fundamental element in the Z-BIKE is its new 20 Ah battery (scooter battery), that delivers 100 km autonomy on plane terrain and 40 km on mountain or mixed terrain (uphill and planes).  
Such high capacity battery offers a longer lifetime, and under this configuration and conditions, it is less stressed than the average smaller ones.  
The electric motor, chosen for our particular terrain, is a robust brushless 500 W Motor, electronically controlled so as to provide 250W instead, which results in an improved acceleration and higher torque available uphill.

Z-Bikes are supplied with a powerful Li-ion scooter battery rated at 36V and 20Ah, and this guarantees an autonomy of around 100 km running at 30 km/h with a pedaling contribution of 50% from the electric motor. Here in Ticino, due to the countless number of uphill slopes, we can guarantee a real autonomy of 40 km with a full charge; in order to assure such autonomy, it is nevertheless necessary to provide a good pedaling contribution. One of the main advantages of the Z-Bike with respect to classical pedal assisted e-bikes, is the fact that you can instantaneously control the amount of power supplied, by means of the accelerator handle; in other words, one could easily run even 200 km by limiting the use of the motor on the steepest uphill slopes.

Z-Bike can certainly be used in place of a scooter or a moped. Regular 10 to 20 Km and return trips are certainly ideal for this means of transportation, (mainly due to time required). For longer trips, a certain passion for the bicycle is also required, and you must add 10-15 minutes more time to reach your destination compared to a scooter. We have customers who normally cover a distance of 30 or more kilometers to go to work everyday.

Z-bike has a 500 Watts electric motor electronically limited to 250 Watts, which offers the optimal torque necessary for our territory, and together with the 36 Volts 20 AH battery, guarantee the optimal currents and ideal autonomy for our topography.

 

LiFePO4 BATTERY

The Lithium Iron Phosphate (LiFePO4) batteries are based on Lithium Ion, but they offer many advantages over LiCO2 (Lithium Cobalt), frequently used in laptops, mp3 players and cell phones. They also offer a greater range, power and safety, in an electric vehicle - they will not explode or catch fire if overcharged.

Z-bike normally use LiFePO4, 36 Volts, 20 Ah Batteries, these are scooter batteries, which guarantee enough power and autonomy for our Ticino territory.
The Lithium – ions batteries present us with several advantages over the older technologies (such as Lead acid, Nickel Cadmium, Nickel Metal Hydride):

  • They do not have the undesirable memory effect.
  • They can produce very high currents in relation to their weight.
  • They give double the autonomy with the same weight related to other technologies.
  • They can be charged in a couple of hours.
  • They handle well the currents generated by the energy recovery under braking.
  • They are less polluting than previous technologies.
  • If they are stored during a long time, they discharge very slowly.

Using the standard charger, it takes approximately 5 hours to fully charge.

The battery has the capability to be fully charged in only 2 hours, the problem is that such chargers are very expensive and not commonly used; furthermore, a slower charging process makes the battery life extend.

 

Battery Comparison Performance Energy Throughput Safety Cycle Life Remaining capacity after high discharge rate Depth of Discharge Recharge Time Working Temperature Range Weight Size Environment Maintenance
LiFePo4 110Wh/kg, almost 3x better than Lead-Acid no explosion, will not catch fire under collision, over charged, or short circuit, high thermal stability up to 500C 2000-3000 times >90% 100% > 4 times faster than lead acid due to high charge current -20C to 70C 1/3 of lead acid 1/2 to 2/3 of lead acid Non-toxic, very environmental friendly No
Lead-Acid 40Wh/kg Not stable in collision or high temperature 300 times 60%-70% 50% Long 0C to 55C Heavy Large Very toxic Yes

 

Differeces with an automatic assisted pedaling system:

The automatic assisted pedaling system is very popular today, but we prefer to manually determine the amount of power required; this guarantees better handling and a much more instinctive control of the bicycle. The pedal assisted bicycles have generally y command that allows the user to limit or increase the percentage of energy provided by the motor. However, we prefer a different approach to the project, where the command is instinctive and the response immediate given by the electronic “gas” or “throttle” handle (such as in a scooter or moped).

The Z-bike complies with the current laws, since it is a pedal assisted bicycle, but the power is manually controlled.

The current Z-bike version is supplied with the optional energy recovery feature. The energy recovery or recharge, is activated with the brake lever, and it acts mainly making the motor to work as an electronically controlled magnetic brake; the energy produced by the braking process goes to recharge the battery. During normal use, the total recovery amounts to an 8% to 10% and with a more accentuated use with important downhill slopes, it can reach 25% from what is used to climb the same uphill slope.

How much energy does Z-Bike consume?

Z-Bike spends about 1 KWh for every 100 km on flat terrain, and the value has been measured from the electric grid, considering all leaks and loses due to the charger and charging process and its use. Power consumption 1 KWh for every 100 km in plain terrain, equivalent to 0.2 liters of gasoline for every 100 Km, with a cost of around 15 cents per 100 km traveled. Power consumption in mountainous terrain is 2 KWh for every 100 km in mountain terrain, equivalent to 0.4 liters of gasoline for every 100 Km, with a cost of around 30 cents per 100 km traveled. e-Bikes must be considered the most ecological powered means of transportation at all, second only to normal man powered bicycles, and it can be explained as follows:

  • The weight of the vehicle is relatively low, between 25 and 30 kg, therefore the ratio between the person being transported and the weight of the vehicle is highly optimized.
  • e-Bikes have an excellent sliding capability specially at low speeds, therefore the drag coefficient is minimal compared to scooters.
  • The electric motor in the e-Bike is “helped” by the energy supplied on the part of the pedaling rider, reducing considerably the energy consumption.
  • Electric brushless motors have an efficiency of 70 to 80% compared to gasoline engines (ICE – Internal Combustion Engines), with an efficiency of only 15 to 20%.