Somewhere between the time Honda introduced its torsion springed CB450 in 1965 and when the last Triumph Bonneville rolled off the Meriden production line in 1983, the parallel-twin became motorcycling\u2019s powertrain pariah. Indeed, for those who actually lived \u2014 and rode \u2014 through motorcycling\u2019s four-cylinder revolution, vivid is our recollection of parallel-twins as junkers. Kawasaki\u2019s 440 LTDs and the Honda CB 450 Nighthawk were the worst of our industry, pumped out without passion or purpose. Seriously, if a 440 LTD were the last bike on earth, I\u2019d have to decide whether I wanted to continue motorcycling.<\/p>\n
Fast forward a decade or two and my, oh my, how the times have changed. Litre bikes have become so powerful that few can ride them and even fewer can afford their high-techery. Four-cylinder middleweights, meanwhile, are all but extinct, their combination of high cost and minimal development over the years all but killing the segment. In fact, look around and you\u2019ll find that, amongst the Japanese at least, the four-cylinder engine that ruled the motorcycling roost since 1969 \u2014 the year of Honda\u2019s CB750 \u2014 is not in much favour. Suzuki has dropped out of the superbike segment and the four-bangers that it still does sell all date back to the early 2000s. Honda\u2019s fours are also pretty long in the tooth, too. MV Agusta has all but dumped fours as well and BMW seemingly continues on mainly because it wants to race in World Superbike. The days of inline fours dominating mainstream motorcycling are quickly coming to an end, replaced by\u2026<\/p>\n
The return of those once lowly parallel-twins. And while the (new) Triumph soldiered on with twins and Yamaha stayed the course with its Super Tenere and TDM 900, it\u2019s Honda that really started this re-legitimization of the classic two-cylinder format with its 2016 Africa Twin. And, though many of us \u2014 including yours truly \u2014 thought it would remain an anomaly, pretty much everyone has copycatted the world\u2019s largest motorcycle manufacturer. Yamaha followed with its Tenere 700, Aprilia with its 660 and Kawasaki, well they really never did give up, its 649-cc \u2014 powering both Ninja and Versys \u2014 the one mainstream twin that defied time.<\/p>\n
Initially, the introduction of new parallel-twins followed a common theme: most manufacturers introduced their parallel-twins as budget bikes. Thus, Yamaha introduced the MT-07 and soon, the R7. Ditto Aprilia and its adventure-style Tuareg. And yes, Kawasaki had, as I mentioned, the Ninja 650, but, just as with Honda\u2019s CB500R, no one in their right mind took it seriously as a sportbike.<\/p>\n
I think KTM has to be given credit for lending the lowly parallel-twin some performance bona fides. Where all of the bikes mentioned in the above paragraph \u2014 with the possible exception of the recently introduced Aprilia \u2014 were lo-po machines that exuded ease-of-use over scintillating performance, the \u201cReady to Race\u201d Austrians refused to accept that putting two pistons in a line would doom it to mediocracy. Where previous parallel-twins were tedious torquers, KTM\u2019s 790, 890 and soon-to-be 990s all rev their nuts off, the 890 pumping 119 horsepower in its most prodigious guise. That would seem sufficient enough to encourage the Austrian trendsetter to dare to render a legitimate sportbike \u2014 the much-anticipated RC 990 \u2014 powered by a parallel-twin.<\/p>\n
Yamaha\u2019s Tenere 700, meanwhile, is considered the true off-road adventurer\u2019s primo ride and this year Honda is bringing back not only its famed Transalp adventure tourer but also the much-missed Hornet naked, their shared parallel-twin replacing both a V-twin and an inline four. Look around and it appears that the once lowly twin is replacing the majority of higher-tech engines. Hell, Suzuki, which many had given up as dead, actually released its first all-new motor in more than 20 years and it is, you guessed it, a parallel-twin (with a 270-degree crank and two counter-balancers).
\nSo why all this focus on parallel-twins?<\/p>\n
The answer is three-fold. First, and most obvious, is that they\u2019re easier to package. V-twins, at least the longitudinally-mounted versions, are longer and fours are wider. Both alternatives have either more exhaust pipes to route or a more complicated pathway. And since twins have less piston \u2014 and, more importantly, ring land \u2014 circumference to hide unburnt gasses, they more easily meet stringent Euro5 emissions standards than short-stroke, big-bore fours.
\nMore importantly, especially in this day and age, is that they\u2019re cheaper to build. They have 50 per cent fewer pistons, valves and connecting rods compared with a four and half the number of cylinder heads, camshafts and cam chains as a V-twin. The crankshaft is more compact, it\u2019s easier to stack the transmission shafts, and the induction system is way cheaper to engineer. Other than the addition of the counter-balancers needed to quell their vibrations, everything about a parallel-twin is cheaper and\/or simpler.<\/p>\n
That\u2019s especially important as the age of internal combustion is (supposedly) coming to an end. Keeping R&D dollars devoted to ICEs low is essential if motorcycle makers are to make a smooth, economical transition to electric powertrains. There\u2019s not much point in developing a radial-valved, four-cylinder engine \u2014 as MV Agusta famously did for its comeback motorcycle, the 1999 F4 \u2014 if they\u2019re going to be banned in a few years.<\/p>\n
In the meantime, they build cheap and cheerful parallel-twins.<\/p>\n","protected":false},"excerpt":{"rendered":"
Somewhere between the time Honda introduced its torsion springed CB450 in 1965 and when the last Triumph Bonneville rolled off the Meriden production line in 1983, the parallel-twin became motorcycling\u2019s powertrain pariah. Indeed, for those who actually lived \u2014 and rode \u2014 through motorcycling\u2019s four-cylinder revolution, vivid is our recollection of parallel-twins as junkers. Kawasaki\u2019s […]<\/p>\n","protected":false},"author":1,"featured_media":49613,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[2407,1876],"tags":[2414,1422,2252],"yoast_head":"\n