I wanna tell you a story, when I was a boy, (a few years ago) (but I didn't say I'm grown up now!) Triumph and BSA made racers out of the Trident and Rocket 3 bikes, Rob North made the frames, Doug Hele was in charge and they really got them going fast, about 80 BHP if I remember correctly, John Cooper beat Ago on the MV fair and square at Mallory and Brands, in 1971 all the 10 bikes in the Anglo/American match races (later to be called the Trans-Atlantic challenge) were supplied by the race shop. Back to the topic, they had a cut out strip on the left bar which was a manual quick shifter, the rider just touched the strip and hit the gear lever, (which of course was on the right, the correct place for it, (anyone heard of cross co-ordination?) also the direction was down for up, instead of the numpty up for up we have to put up with now, why you may ask? it's much easier to push to lever down when lying flat on the tank, and when you're hard on the brakes sitting upright it's easier to hook to lever up, (ever seen racers knees keep flicking out when approaching a corner?) and it would stop the need for short shifting when banked over,) The next advance was to use the rev limiter as the quick shifter, this was really difficult to get right and never caught on I think. At the time of all this going on I was a keen spectator at most of the, what was known as 'the home internationals', I rode a pre-unit Bonneville with mag ignition, they had a cut out button on the bars as well, it was a delicate art to get it right, but 3rd to top (only 4 gears then!) sounded really 'slick', when I wanted to be a hooligan, (don't get the urge to be one quite so often nowadays) I would hold the throttle open while pushing the kill button, when I let it go there would be an almighty back fire, my god it used to make the grannies jump down the high street!!! (now I'm old enough to be one myself). Lastly at a little track in France called Folembray, the 'cool' guys go past the pit wall hanging onto the quick shifter a little longer and get the same backfire.