October 22, 2007 The 2007 Panasonic World Solar Challenge got underway yesterday with 40 teams from across the globe competing in the 3000 km race from Darwin to Adelaide in Australia. Among the competitors in the Greenfleet Technology Class - a category for internal combustion vehicles promoting an enhanced environmental profile - is the BioBike, a biodiesel-powered motorcycle, constructed by a group of students in Adelaide, Australia, that happily does 96kmh and returns a staggering fuel economy of only 2.2 litres per 100 kilometres. As the design is further refined, BioBike’s creators expect this to drop below the 2 litres per 100km mark (around 107 miles per gallon), and they believe it can be manufactured for around the same cost as a petrol-powered dirtbike.

Diesel cars are well-established in the market and renowned for their ability to deliver excellent fuel economy in comparison with their petrol brethren. But why haven’t we seen more diesel motorcycles? Well, diesel engines run extra-high compression pistons, and their sparkless ignition produces much stronger power pulses – which gives them excellent torque, but means that the engine casings need to be thicker and heavier to deal with the increased stresses.

In the leisure motorcycling world, where power-to-weight ratios are everything and horsepower rules over torque, diesel simply doesn’t make sense on the sales floor.

But, as BioBike project leader Heidi McNamara points out, in areas where motorcycles are used as essential transport rather than high-speed toys, these machines start to look far more practical - particularly on farms and in military applications where diesel is used to run pretty much every other vehicle and engine.

The rise of biodiesel – which can be made from recycled vegetable oils and animal fats – has given diesel vehicle operators the additional advantage of being able to make their own fuel. It’s not only environmentally friendly and sustainable, it’s also a far better engine cleaning solvent than regular diesel.

The BioBike project team designed and built the bike as part of their final year Mechanical Engineering project at the University of Adelaide. It’s Australian Design Rule compliant, allowing it to be registered for road use, and it is currently participating in the GreenFleet alternative engine technology class at the Panasonic World Solar Challenge - meaning a 3,000-plus kilometer ride from Darwin to Adelaide.

The engine is a stationary 10-horsepower Yanmar L100AE 400cc diesel generator, running through a scooter-like Cornet 500 continuously variable transmission (CVT). The CVT was chosen simply because it was readily available and compatible with the Yanmar engine.

The engine and transmission were fitted to a modified Husaberg Enduro frame, so the chassis uses all the top rated gear from White Power and Brembo in all the right places. It’s heavier than the donor bike, at around 130kg, but still very lightweight for a road-going bike.

The project is the continuation of the achievements of the 2006 the BioBike Team's achievements in successfully designing, manufacturing and testing Australia’s first biodiesel motorbike. In its next phase the BioBike may become a PHD project with the goal of building an all-new biodiesel engine from the ground up and may even lead to biodiesel bike competing in the Dakar Rally one day.

The group has no commercial plans for the bike at this stage, but there’s been a lot of interest from the farm owners who have seen the bike, as well as from Asian manufacturers who can immediately see the benefits of a highly economical, low-emissions motorcycle. We wish the team the best of luck in the Panasonic Solar Challenge and look forward to hearing whether they manage to break the sub-2 liters per 100km barrier.

View gallery - 4 images