The "Sooraj diesel" bike
the beauty of this is that it gave the highest mileage ever, about 86 kpl ! beats even the hero honda splendor !
but yes there were certain shortcomings too: the vehicle would vibrate badly at lower speeds.
also another peculiarity was that the engine generated its maximum torque at a very less rpm, and though the vehicle could be started off from standstill in top-gear, the maximum vehicle speed was limited, because the engine torque would gradually decrease with increase in rpm.
now what do you think went into designing the engine ? had the vibration got anything to with the speed-torque characteristics ?