Fans of weird and wonderful concept bikes will be rather taken with the 36/28 Postale, described by its creator Italian designer Paolo De Giusti as an 'urban pursuit' bike. It's like no urban bike we've ever seen.
De Giusti isn't a stranger to bicycle design. In 2013 he developed another concept bike, the XXXVI DG, which featured 36in wheels and an innovative and creative frame which broke many traditional bicycle design traditions.
Although De Giusti has developed designs for everything from motorcycles and lighting systems to robotic chairs and ball point pens, he is drawn to bicycles.
"Bicycles are beautiful products to create, talking as an industrial designer," he told BikeRadar. "There are hundreds of different variations using only the classic eight-tube frame configuration, and the materials available today give you the freedom to created infinite options. At the end of the story you create something that gives you a smile when you ride."
The saddle attaches directly to the frame
One of the first things that will strike you about the Postale, which De Giusti also describes as a 'massive messenger bike', is the fact that the rear wheel is larger than the front: 36in compared with 28in, the numbers from which the bike gets part of its moniker. The rear wheel consists of an alloy rim mounted on a Nexus hub, which provides the gearing, with a neoprene outer cover. On the front, a slightly more conventional Specialized Fatboy tyre sits on a standard alloy rim with radial spokes.
If the wheel size setup looks vaguely familiar, that's because it's inspired by mismatched wheels of certain track bikes in the 1980s and 90s. These also featured a large rear/smaller front wheel system though this was primarily to help riders attain an aerodynamic position on the bike.
"The concept for this bike is linked to my previous bike, the XXXVI, which started my interest in 36in wheel," said De Giusti. "The 36/28 Postale brings to life the old spirit of the velodrome bikes used for the Hour Record, such as the beautiful bike used by [Francesco] Moser. But in the Postale, this spirit is adapted for a road bike which can be used as a transportation – and that can give new meaning to the riding experience."
De Giusti claims that these wheel sizes, combined with the frame design, make the bike run smoothly over rough road surfaces, and the frame itself is designed for everyday riders rather than athletes from a minimum height of 1750mm or 5ft 7in. Combined they produce a bike with a wheelbase of 1090mm.
The frame design and construction are worthy of a little more investigation. Designed to be vertically symmetrical, the Postale breaks with the traditional combination of quadrilateral frame with rear triangle in favour of isosceles triangles front and rear. The result is a bike with a minimal head tube and without a seatpost – the saddle attaches directly to the point where the front and rear triangles meet.
"The visual effect is strong," De Giusti said, "but the ergonomics are not so far from a common road bike. The bike looks like an arrow moving forward."
The fork is unusual to say the least. Designed in an 'F' shape, the two prongs of the F act like a double stem, attaching to the top and bottom of the head tube to lengthen the reach. Short bullhorn handlebars are fitted with twin clamps either side of the head tube.
The forks is F-shaped, and attaches to the to and bottom of the head tube, with the prongs of the F acting like a double stem
White aerofoils attached to the forks are a design feature, rather than serving a specific practical purpose, and the saddle includes a black cover that hooks over the top and around the top tube.
The concept model frame is made from 3D-printed ABS (a type of thermoplastic polymer) and PVC, which allows simple tweaks to the design, but is not robust enough for actual riding. De Giusti anticipates that production models would either be made from alloy, or a combination of 3D-printed alloy junctions and carbon tubing.
In addition to the Nexus hub, which provides internal gearing, the moving parts are off-the-shelf and considerably more normal-looking than the rest of the bike, including a 100mm fat bike bottom bracket.
Despite all these elements, the 36/28 Postale is still most definitely a concept bike. While it might be eye-catching, De Giusti admits that the wheel configuration and design is "not the best for a utility bike, but the project gives more importance to other aspects". He suggests, for example, that the large rear wheel would be an ideal location for installing an electric motor.
But will it ever come to production? Probably not is the answer.
"There is no plan to mass produce, though of course this could be the natural development of the process," De Giusti said. "To move to the next step it would be necessary to find a technical partner who could engineer the frame and build it – and I have some doubt about the ability of this kind of internally geared hub to withstand the torque necessary to move the rear wheel."
And as for who De Giusti would envisage riding this type of bike, the phrase 'gentleman rider' comes up. "Someone who uses the bike every day, and is inclined to tolerate some discomfort in exchange for a special experience."