KIWIMADE KIWI’S AND THEIR NEED FOR SPEED Whenever you’re trying to be the best, the fastest, the biggest, it’s a monumental task, but that’s exactly what Phil Garrett of Flying Kiwi Motorcycles plans to do: build the fastest motorcycle ever recorded in New Zealand. “We have almost completed two turbocharged bikes and will be attempting a new New Zealand record in South Canterbury in early 2018, our target is 320 kmh." For over a year, Mr Garrett says he and his team have been working on a new innovation, installing a second gearbox using planetary gears inside the rear wheel of our bike which (in theory) adds 140km per hour to the top speed with no changes to the engine. “The planetary gear hub was an innovative solution to a tricky problem, even with the smallest rear sprocket and the largest front the bike would still only go 286km per hour at 9000 rpm. We brainstormed all our options and this idea came up (inspired by a Sturmey Archer bicycle) and we decided to get an engineer to draw it up and see if it would work - Pete Jones from Diamond Harbour - did the drawings and then offered to make it for us. We used the planetary gears from a V8 BMW automatic transmission and Pete made the rest and carved out the rear wheel to accept it. Almost a year on from the inception it is now complete, in theory it takes our maximum speed from 286 to 406km per hour… with no changes to the engine,” says Mr Garrett. It works by adding an overdrive between the sprocket and the wheel inside the hub; for every rotation of the sprocket the wheel goes round 1.5 times and Mr Garrett says, “it’s a bit freaky to watch even now. We have solved all manner of problems as they came up including lubrication and balancing the hub, but we always found a way to get around them.” He says that recently the team ran the hub and the bike on the dyno for the first time and it performed perfectly, with no breaks or leaks and they achieved an equivalent speed of 240km per hour on three occasions. “I was very surprised to learn in the course of my research that the last recorded fitment of a planetary hub into a motorcycle was back in 1907. No one appears to have done it for more than a 100 years… they are fitted in every automatic transmission, all electric bicycles and most big trucks but not in a bike. “I believe this small step is yet another New Zealand contribution to the motorcycling world, another innovation that no one thought of before.. “I would like to tell people about what we have built and hopefully inspire others to do the same and go faster... imagine all the Bonneville bike records getting beaten with these hubs. There is no mention in any rule book about planetary gears.” www.engineeringnews.co.nz 35
EN-Feb18-eMag
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