The Isle of Man is home to the International TT Race, the annual motorcycle event that attracts more than 50,000 people to the island, a large amount when considering that the island has only 85,000 inhabitants.
In 2010 TT introduced the TT Zero electric motorsport event which replaced the TTXGP race as a one-lap circuit of the Snaefell Mountain Course. The TT Zero-class is for motorcycles powered without the use of carbon based fuels, which mainly use lithium ion batteries. Despite initial doubts, the popularity of the electric race has grown significantly each year.
This year, seven electric motorcycles stood in line under a glorious sunshine in anticipation for the start of the 2015 TT Zero race. Despite there being no gears and no engine noise, the races attract a ride audience and the top riders agree that the electric races are a lot of fun, as well as attracting a new interest for the TT races.
Adrian Moore is the development manager for manufacturing and inward investment at Isle of Man government, and explained that the TT Zero races are a great step for the island.
“The race is not only a human challenge but an engineering challenge. When electric bikes first started in the race back in 2010, they were a bit of a joke in the traditional bike community, but it’s not like that anymore. The teams working on the bikes are producing some fantastic engineering products, putting carbon fibre together by hand and making major steps in developing the technologies needed for the race, and now people are taking them seriously.”
The teams involved in the race included Mugen, Victory Racing, Sarolea and TMR, as well as university teams Kingston, Nottingham, and Brunel, who brought prototype e-bikes.
All participants were fiercely competing with weight and power to obtain the fastest time around the lap, and PE met with some of the teams to learn just how they had engineered their bike in a bid to get the fastest lap.
Sarolea is the oldest Belgian brand of motorcycles, and in September 2015, Bjorn Robbens and his twin brother Torsten arrived on the island with the Sarolea SP7 race bike. Every year since, Bjorn Robbens explained that the races are even more challenging and that the bike they produce has to significantly improve.
“One of the main challenges this year has been detracting the heat from the batteries when running the high performance motorcycle. Last year we changed to an air cooled motor which worked fine and this year we optimised the software so the bike is aware of what the power consumption should be and will modify the performance to suit this.
“From a technical point of view, we are always working to improve batteries the most. Batteries are so heavy so it’s finding a sweet spot between weight and handling. We have been using carbon fibre to lightweight the bike as weight is key enemy to any electric vehicle.
Robbens continued: “The aerodynamics of the bike had to change this year too, and we can only improve that in the future. Going at these speeds, aerodynamics is really important. The bike is already really narrow and we’re constantly working to make it even more aerodynamic.”
Team Mugen confirmed its presence in the TT Zero Challenge with its Shinden Go bike, which Colin Whittamore, Mugen’s general manager explained was to compete in the race with more than 400 volts of batteries, enough to go 137.3 miles at 127mph on average.
“Five years ago, no one had ever lapped the circuit here at TT with an electric vehicle at 100mph; now our target is to do 122mph.”
However, Whittamore explained that this goal doesn’t come without significant challenges. “To carry a battery around is a lot of weight, on average it is 100kg heavier than a normal bike, but everything else that can be on the bike is made from carbon fibre.
“An even bigger challenge, however, is not having enough battery to get around but having enough heat control. The motor we have created is therefore oil cooled and the inverter is water cooled, and we are using air cooling for the battery pack.”
Kingston was among the universities to enter a bike into the TT Zero race. Dr Robert Rayner, senior lecturer in motorsport engineering at the university and project lead, explained that the university has spent the last year sourcing a new battery and testing its safety for the race. “This is our Mark 2 bike which has been through several evolutions since Mark 1. We have engineered a brand new controller into this year’s bike as the old one was too heavy and not flexible enough.”
Rayner explained that while it is challenging for a university to compete with the likes of Mugen racing, the bike holds the land speed record of 160 miles an hour which the university set in 2011.
“The bike has enough power for about 100 miles at road legal speeds then a charge of five hours,” said Rayner. “By competing in the race, we want to show that it’s not just something a group of engineers have thrown together. The bike is attractive, feasible and useful and engineering it provides a great experience for our students to get involved with the mechanics, technology and something they might not otherwise have the opportunity to do.”
The growth of the TT Zero-class, and the serious engineering going into these bikes, seems set to accelerate the electrification of motorcycles.