The Anura has an aluminum frame, a differential that drives both rear wheels, and front wheel steering geometry "designed so that when one front wheel leaves the ground, the other seamlessly takes over all the steering control." If you have ever ridden a quad down a bumpy hill you know why that would be interesting, and if you use a quad in snow the two wheel rear drive is a big plus.
Bent Rider Online said it was very stable and "it was definitely one of the funnest machines on the test track." There is a kit to convert the Anura Trike to a fourwheeler.
It has long-travel four wheel suspension, a rear differential with two driven wheels and an upright rider position that is secure on jumps and permits using the legs to muscle the bike.
Films (some on the Web site) are impressive when powered by Andy Contes, a former top-ranked pro BMX bike racer.
They also have a four wheeler constructed of two side-by-side linked bikes for those who can ride in normal biking posture.
Brox HPVs in Manchester, England, has a four wheeler that comes in various configurations and is designed to carry cargo.
They order batches of the two and four-seater Dutch Quattrocycles described below.
They use some off-the-shelf components and some components manufactured just for them.The model without electric assist is lighter and more of a road bike.Electric Bike Car Co has several models of their Ebikecar four wheelers that come as pedaled bikes or with electric motors.They have one model with a single bench seat and another with two seats. The Web site mentions drum brakes but does not mention gears.Carvx is a Dutch company with a four wheel mountain bike with four hydraulic brakes, full suspension and hub gearing.