The VanMoof S4 and X4 e-bikes have been revealed; the bicycles are launching in the US and EU in May and will arrive in the UK in June. The new models have a top assistance speed of 20 mph (~32 kph) and can travel up to 87 miles (~140 km) on a single charge. You can control various features via an app, and anti-theft tools include GSM location tracking and a rear wheel lock.