Every now and again, astute Gizmag readers come to the fore to keep us on our toes - and never has this been better demonstrated than with last Friday's D-Drive Infinitely Variable Transmission article
. More than 40 comments and e-mails have flooded in over the weekend questioning the D-Drive's capabilities as a true IVT, and its potential efficiencies. Furthermore, an engineering report was made available on the D-Drive website that flat-out negates some of the key claims that were made in our interview video. So let's take another look at this device in the harsh light of engineering scrutiny.
Ready for a bit of a mental mechanical challenge? Try your hand at understanding how the D-Drive works. Steve Durnin's ingenious new gearbox design is infinitely variable - that is, with your motor running at a constant speed, the D-Drive transmission can smoothly transition from top gear all the way through neutral and into reverse. It doesn't need a clutch, it doesn't use any friction drive components, and the power is always transmitted through strong, reliable gear teeth. In fact, it's a potential revolution in transmission technology - it could be pretty much the holy grail of gearboxes... If only it wasn't so diabolically hard to explain. We flew to Australia's Gold Coast to take a close look at the D-Drive - and it looks to us like Durnin has pulled a rabbit out of his hat. Check out the video after the jump and see if you can work out if there's a catch.