Benda Supercharged V-twin

[Hugh Janus]

Benda has patent documents showing this supercharger, which is interestingly driven off a camshaft. (Benda/)

A year ago Chinese bike maker Benda—one of the most ambitious brands to emerge from that country’s fast-growing bike industry—filed design registrations for its VTR-300 Turbo sportbike and now a new patent application from the company shows what might lie under its bodywork.

Benda first revealed the VTR-300 Turbo idea back in January 2021, releasing silhouette images of three bikes it planned to bring to market in the coming year. Two of those models, the LFS700 four-cylinder streetbike and the VTC-300 V-twin cruiser, were launched on schedule before the year was out. The third was the VTR-300 Turbo, clearly a full-faired sportbike, and two years on it still hasn’t been officially revealed.

The motorcycle that the supercharged V-twin will allegedly power, called the VTR-300 Turbo (yeah, we know it’s not a turbo…). (Benda/)

Instead, in January 2022, the design registrations for the bike showed up, giving a good look at its styling and construction via CAD images but leaving us in the dark as to the tech underneath. It clearly used the firm’s liquid-cooled 298cc V-twin—the same 60-degree engine that’s used in the company’s small cruiser models—but the “Turbo” element of the original teaser remained a mystery. We speculated that there could be a small, exhaust-driven turbo mounted low in the fairing ahead of the engine, a layout that Honda tried nearly 40 years ago for the V-twin Honda VT250F Turbo prototype, a project that didn’t reach production. But now Benda’s patent application suggests that the bike might not be turbocharged at all, but instead use a mechanically driven “supercharger.”

That might not jive with the Turbo part of the VTR-300 Turbo’s name, but bike manufacturers aren’t always above playing a bit fast and loose with definitions, and when you throw in the fact it’s a Chinese company using an English word, the chances that in this instance “turbo” has been erroneously used to mean “supercharger” becomes quite high. Alternatively, Benda might be trying both forms of forced induction in its efforts to get more power from that tiny V-twin engine. In normally aspirated form, the motor is good for around 30 hp, but boost could easily increase that figure to as much as 50 hp.

A cutaway view of the supercharger and SOHC cylinder head. (Benda/)

The supercharger system shown in Benda’s patent application is far from conventional. Instead of being driven from the crankshaft, the tiny blower is mounted on one of the engine’s SOHC cylinder heads and takes its drive from the camshaft. The supercharger itself appears to be a centrifugal design, like Kawasaki’s supercharged H2 models. Typically, centrifugal superchargers—which have a compressor section similar to that of a turbo but are geared to the engine instead of using an exhaust-driven turbine—work best at high rpm, while a positive-displacement supercharger offers more low-rev grunt. Benda’s supercharger compresses intake air and pushes it through an intercooler and a single throttle body and then through a Y-shaped duct into both cylinders’ intake ports.

The supercharger forces the intake air into a single throttle body and then splits into twin ducts headed to the intake ports. (Benda/)

The patent suggests the mounting and drive system is more compact than a conventional, crankshaft-driven design, although the fact the camshaft turns at half crankshaft’s speed means the supercharger needs to be geared up considerably to get enough rotational speed. In an additional section of the patent, the designers suggest fitting a variable-ratio drive with a V-belt running in adjustable-width pulleys rather like a twist-and-go scooter’s continuously variable transmission, to maximize the supercharger’s speed throughout the engine’s rev range.

This image is of a proposed variable-ratio drive with a V belt, similar to a scooter’s final drive. This would be to maximize supercharger impeller speed throughout the rev range. (Benda/)

Since the Benda VTR-300 Turbo has already missed its initial intended launch date of 2021 and the company hasn’t referenced the bike in more than a year, the project may have stalled. However, Benda, which has launched a remarkable run of new models in the last couple of years including some of China’s first inline-four motorcycles and, in late 2022, the nation’s first V-4-engined machine—has admitted over the last few months that it’s had problems scaling up production to cope with the new designs and to meet customer demand. With that in mind, it might be a sensible move to put the VTR-300 Turbo project on the back burner until those problems have been solved.

There’s also the question of the company’s international plans. Benda does have a small presence in Europe, but again it appears that the company’s first priority is to get on top of its supplies for the Chinese market before attempting further expansion. Will we ever see the VTR-300 Turbo, whether it’s turbocharged or supercharged, in the States? It seems a long shot at the moment, but in an era when so much R&D focus is on electric bikes it’s heartening to see efforts are still being made to improve the internal combustion engine.

Source

[Pedro]

Not the greatest choice of brand name to sell in the UK

[XTreme]

2 minutes ago, Pedro said:

Not the greatest choice of brand name to sell in the UK

Maybe @Six30 would be up for riding a Benda?

[Six30]

5 minutes ago, XTreme said:

Maybe @Six30 would be up for riding a Benda?

has it sent you a pm giving you a severe drunken warning ?

[Buckster]

31 minutes ago, XTreme said:

Maybe @Six30 would be up for riding a Benda?

Wouldn't be the first time.