Lots of folks (Thanks, Make blog, Real Tech News, Treehugger, Metaefficient and a lot more) picked up on our biodiesel motorcycle post the other day where I mentioned the possibility of combining biodiesel with the performance of the Thunder Star 1200 TDI.
It does seem a few misread what I said, I have no idea whether Star Twin has tried or tested biodiesel in their bike. It seems logical and desirable to do so but there’s no indication that they have done so or intend to. My post mentioned the potential of the combination which I think would be extremely positive.
The most referenced figure in the article was the 150mpg that Star Twin claims. When I first posted, I didn’t mention that figure because I thought it was a bit high, but after looking at the mileage of the standard VW Lupo which is well above 60 in the car and some have taken it to 90mpg and more, the 150mpg figure in a much lighter motorcycle does not seem out of reach.
The figure that the more technical readers found most interesting was the 250 foot pounds of torque at 5500rpm and as the engine guys out there know, torque is the grunt that makes a bike fun to ride and 250 foot pounds is huge. Last night, Andrew posted a comment that questioned the figure, and after looking at the numbers again I tend to agree.
Without going into the math too much the 5500rpm seems like it is incorrect and 2500rpm seems almost dead on. (For a good explanation of conversions go here for horsepower formulas and here for torque conversion.) This actually sounds even better from a rider’s point of view since that much torque down low would be VERY usable in real world riding.
At this point, we still need to confirm what the real numbers are but I think the 2500rpm figure is more likely correct. I’m doing more digging but if any Kneeslider readers can confirm these figures or shed more light on them we would love to hear from you. If some of our European readers over in Holland can contact Star Twin, we would especially appreciate your input.
For those interested:
(Torque * RPM) / 5252 = Horsepower so 250*2500/5252=119.002