SAFETY NYSTROM SPECIAL
Safety is our highest priority here at Nystrom Bike. It affects every aspect of our business, from design, prototypes, testing, redesign, validation, certification to the final production phase.
Our ebike is a robust design for a long tough life. We made the frame with dual upper frame tubes, it makes the frame very torsion resistant. We use chrommoly steel, a material often used in the aerospace industry due to its high strength combined with its ductile character and superior welding properties.
Safety systems – Electric safety: Our ebike has a very well engineered electric system. It’s not enough that it works – It must work SAFELY. We only use high quality electric components, install them correctly and finally test the electric system.
Our electric system also incorporates many safety features, such as the battery management system which monitors the battery and its performance. The motor controller is also designed with several safety and monitoring features. The bell is also a safety detail.
The controller pulses current to the motor as appropriate, the controller is considered the brain of the ebike. The controller gets its information from several electric sensors on the bike. Two of them are installed inside the brake levers which send information that the rider is applying brakes. The controller senses this and immediately cuts all motor power. Other parameters sensed are battery voltage and current, as well as motor temperature. If the motor gets too hot, the controller reduces power until it cools down. The controller performs various other safety functions as well.
The battery contains a lot of energy which must be controlled in a safe manner. It all starts with using high quality cells. We use the Samsung INR18650-35E model. They have internal protection, and are tested and approved according to international safety standards. The cells are installed and connected, creating a rigid structure. The complete batterypack is enclosed and water proof. Condense is ventilated through an integrated membrane.
BMS (Battery Management System) is an electrical monitoring and protection system installed inside the batterypack enclosure. It is connected to the battery cells and can cut off both the motor current as well as the charging current if needed. It measures the battery voltage down to individual cell level. The battery temperature is also monotored. The BMS is preprogrammed with all the relevant safety features. It also performs cell balancing during charging to achieve optimum capacity as well as long life.
The Nystrom Special is designed with dual safety, both during charging and riding.
Charging – The battery is monitored by both the charger and the BMS.
Ebiking – The battery is monitored by both the motor controller and the BMS.
The charger is included with every bike. If you need an extra, they are available to purchase. The charger works in steps to charge the battery efficiently and safely. The indicator light shows which is the current step. Steady green means the chaging is complete. According to Samsung the maximum charge current is 8A, but they recommend to only charge at 5A to increase battery life. We use a 3A charger which will give the battery a long life. Time to charge the battery is 5hrs, assuming starting with a depleted battery. In real life the battery is usually not completely depleted when charging, so the charge time will be less than 5hrs.
Don’t use the charger if there is any risk it gets wet!
We use Magura brakes, the MT5e. These are specifically developed for high power ebikes, they use hydraulic 4-pot alloy calipers. Very efficient and safe. The quality of the brakes are actually very important for the ebike experience. When you know the brakes are top notch, the riding is much more relaxed.
The Nystrom Special headlight is made from cast aluminium and brass which is polished to a high shine. The large reflector and the H4 LED-bulb makes for good visability when riding in the dark.