To produce the 200 Duke’s liquid-cooled twin overhead cam four-valve single-cylinder motor, robustly engineered for durability as well as performance, the Bajaj/KTM R&D team bored and stroked the 125cc version’s 58 x 47.2 mm dimensions to 72 x 49 mm, for a capacity of 199.5cc. As with the smaller engine, KTM took lessons learnt in developing their highly-stressed 250 motocross engine as the basis for producing the Duke motor, whose four-valve cylinder head with larger paired 28.5mm inlet valves (against 27mm on the 125) and smaller 24mm exhausts (25mm on the smaller engine), still set at a 29.5° total included angle, is very similar to that of KTM’s 250EXC-F four-stroke offroader. The crankcase, six-speed transmission, radiator, airbox, and silencer are all unchanged from the 125 Duke, but the exhaust headers are a larger diameter, and the catalyst is bigger, says Wimmer, who admits his Austrian R&D team has successfully run a 250EXC-F engine installed in the 200/125 Duke’s chrome-moly trellis frame, for even more performance! Just to see, you understand….
However, the step up in output from the 125’s Euro-strangled 11kW/15bhp peak output at 9,500rpm to the new 200 Duke’s 19kW/26bhp, delivered at higher peak revs of 10,000 rpm, already produces a significant increase in power that transforms the KTM junior hotrod into a serious piece of riding kit. Nice as the 125 Duke is to carve street corners and tool around town on, it’s more of a city bike compared to the 200, which is a go-anywhere funbike with the vital added dimension of extra performance. However, it’s not so much that 73% hike in horsepower numbers than transforms the 200 motor into something that’s so much more fun, it’s the commensurate 68% lift in torque from the 125’s slightly weedy 11.8Nm at 8000 rpm, to the 200’s considerably more muscular 19.5Nm at the same revs.
OK, this isn’t exactly Harley-Davidson territory, but it does mean that with an unchanged dry weight of 122kg (134.5kg with a full 11-litre tank of fuel, with 50/50% weight distribution) acceleration is now considerably less lethargic than the 125, and may even be termed sprightly. While the six-speed gearbox has the same flawless operation as before, with a progressive-action clutch that feeds out controllably – though you must always use the clutch to change gear, however experienced you are, since clutchless upshifts are hard to perform smoothly – you don’t need to work it nearly as hard as on the smaller-engined bike, and roll-ons in the higher gears are much more responsive, and immediate, without needing to hook down a ratio and rev it hard to get any sense of zest. This’ll be a crucial feature in the Indian market, where riders resist using revs in order to save fuel, and so get used to short-shifting all the time. They’ll be happy with KTM’s provisional fuel consumption figures for the two bikes, which Andreas Wimmer reveals show an already frugal 2.9lt/100km for the 125 – and just 3.3lt/100km for the 200, in spite of the larger 38mm Dell’Orto throttle body with single top-spray injector, compared to the 125’s 33mm unit. So, 12% more fuel consumption for around 70% more power and torque, and the bikes weigh the same. Sounds a good trade-off to me.
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