Another bike, the Vyrus 984 C3 2V Razzetto, was one of those bikes that used the hub center geometry.
Vyrus is a small Italian motorcycle manufacturer based in Coriano, Italy, and their motorcycles such as the “Tesi” – Thesis in Italian – have their designs stemming from a university engineering project linked to motorcycle legend Massimo Tamburini . The Tesi and Vyrus 984 were instantly identifiable by their use of their center-steered front suspension and steering arrangement.
These fabulously expensive custom bikes have been called “functional works of art,” and they look a bit like something you might see in a video game.
In hub-centered bikes, the front wheel is attached to a swingarm with a shock absorber and internal pivot point. Steering is achieved by using these links to rotate the wheel on a pivot point. Center hub steering has been used on motorcycles for over a century, but the design, despite what some engineers say offers a distinct advantage, never took hold.
But Vyrus founder Ascanio Rodorigo already worked for Bimota as a racing mechanic and engineer in the 1970s and his tenure there lasted until 1985. When Rodorigo finally left Bimota, he started his own business. but teamed up with Bimota on the center-hub. – Directed Tesi. He then deepened the concept of steering and refined it for his own company’s motorcycles.
A Ducati twin spark bored to 1,079cc and producing a 100hp L-twin delivers the horsepower needed for the 319lb (145kg) Vyrus 984 bike, and it is delivered to the road via a six-speed drivetrain.
Now builders like Bryan Fuller of Fuller Moto, Revival Cycles and others have built beautiful machines that are reminiscent of the hub-centric glory days of the Majestic. Manufacturers such as Stellan Egeland used a raised 1200 boxer engine from a BMW HP2 Sport. He also added his own ISR hub center steering setup to a frame he made from 2391 steel tubing. The ISR kit is a thing to see.
Revival’s “The Six”, featuring a fiery Honda CBX engine, is another take on the hub-steering geometry. It was commissioned by museum owner and bicycle collector Bobby Haas for his Haas Moto Museum in Dallas by Revival’s Alan Stulberg and his team.
Stulberg said the commission was intended to pay homage to the classic Art Deco Majestic and added that he and the team have become “obsessed with its design language and its flow” since they first saw the bike at the Barber Museum.
So why aren’t more motorcycles equipped with hub steering systems? They don’t plunge as much under braking and tight corners as conventional telescopic fork setups. They push braking forces back into the frame more effectively rather than transferring immense bending forces to a pair of vertical forks. The driving experience is exceptional as the braking performance in bends is greatly improved.
It works like this: a wheel hub pitches back and forth on a center pivot and is supported by two large steering arms operated by handlebars. The handlebars connect to the front steering and swingarm using complex links. A fixed arm connects a push and pull rod on either side of the center of the hub to help steer the bike. The geometry also includes a second pair of static rods to ensure the axle remains level with the mass of the bike.
While hub steering has a number of obvious advantages, its downside is that it is considerably more expensive to manufacture and maintain, and requires exceptionally experienced mechanics for tuning and repair.
But it looks good, performs technically more efficiently, and directly addresses the most important factor of the rider experience: braking.