Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/1542352
comparison with the V-twin sportbikes of Italian riyals such as Ducati and Aprilia. And that opens new doors for Boxer owners, because this is a bike you can seri- ously plan on usinS at track days - without raising a scornful smile or pitying looks from those sharing the circuit with you aboard such latin lovelies, or from the lapanese sportbike contingent, It's a SuperBoxer Superbike - and the chance to spend a 240-mile day with it tearing up the tarmac along some of Sor.rth Africa's finest roads, and ending with some serious laps at Cape Town's fast but bumpy Killarney race circuit, underlined what a practical yet effective all-around sportbike the new Blvlw has turned out to be. To create the Rl2005, BMW's engineer- ingteam, led by Rainer Baeumel, took as its basis the company's new-generation air/oil-cooled hi-cam Boxer motor from the R|200GS - a fuel-iniected, eight-valve, I l70cc engine measuring l0l x 73mm and scaling in at just l0l pounds, no less than 29 pounds - 8 percent less than its smaller- capacity predecessor. Forged pistons offering a hfh 12.5:l compression ratio are fitted to extm- strong steel connecting rods, but the real work in puEuit of more power has gone into the four"valve cylinder heads. Those at"e now ls-percent lighter than on the R I l00S while still retaining the previous chain- driven hi-cam layout. They've also been re-ported and flowed to suit, as well as replumbed for superior oil cooling. Valve sizes have been ancreased by 2mm all around compared to the Rlloos, with 36mm inlets/3 lmm exhausts (the latter now sodium-filled for extra cooling) repiacing the 34/29mm layout of the older bike. They are set at a 4l-degree total included angle as on the G5, but fltonkr ro rhe fqct fiqt fie t ltw RI2mS cqn bo uccd 06 o 6lrectbike or o with harder springs and reinforced steel rocker arms - plus all-new camshafts run- ning in three plain bearangs rarher than the enduro bike's two. This was done to enhance the stiffness and precision of the entire valvetrain. These cams have an altered profile delivering revised valve rim- ing and greater duration, as well as more lift - l0.95mm on all four valves. ''The problem with this engine is not gettinS more power, but ro do so reliably via higher revs," says Baeumel. "For BMW this means a trouble-free duration of over 100,000 km [6200 miles], and it took us a while to achieve this - but finally, we did! This has been a four-year project to deliv- er this bike to the marketplace, but we're very happy and satisfied with the result- lt's a good bike - don't you think sol" Well, yes, it is - and for reasons that per- hapr surpriringly don't rellect the fact that it's a BMW Boxer with its unique architec- ture, and ail the implied compromises in terms of ground clerrance this entails in sportbike terms with modern tires. Okay, you can't help but clock those sticking-out cylinders when you approach the bike with the key in you. hand - but once you've thrown your leg high enough o\rer the pas- senger seat cover to climb aboard, you'll soon forget it's a flat-twin motor. And that's not iust because the upswept t exhaust silencer - with three-way catalyst delivering Euro 3 compliance - rs so quiet. It's wonh noting thar a bike that looks distrnctly high at rhe rear when ar resr is. rn fact, nothrng ofthe sorL. WetghE disrribution is 5l/49'percent frontlvard, with or with- out a 190-pound rider says Baeumel, and rt's rndeed the case rhaL the ndrng posrtion isn't nearly;ls extreme as on some other sportbikes. There's reaily no! so much body weight on your wrists and shoulders, and all told it seems a rational riding stance. It's actually pretty comfoftable. The only minor downside is thar the rubber grips on the clip-on handlebars are too small: Boxer-sized riding hands demand something more substantial - it's not a l25cc GP racer, BlnlWl But you can't help notice the meafy balance weights hung at the end of each handlebar, which turn out to do their job ofhelping calm any remaining vibes extremely well. Thats once you fire up the Boxer with your right forefinger on the awkwardly positioned button - BMW s swirchgear is iust as con- fusingly idiosyncratic as ever. For these weights are matched ro a pair of gear-driven counterbalancers positioned on a single shaft at the rear of the cylinder block, aimed at smoothing out the second- ary imbalance of a |8o-degree crankhaft, and removing the irritating tingles rhat had become ever more noticeable as engine capacity and particularly rpm of the other- wise perfectly balanced flat-twin Boxer motor had increased- Best of all, they've removed the irritat- ing vibration the old Rl 1005 delivered through the footpegs at constant freeway cruising speeds of 75 mph and up- Riding the new bike at more or less legal speeds on the Jo'burg-Cape Town motor- way didn'r send my feet or fingers to sleep, as on the older bike. What's more, rhe Euro 3 emissions compliance of the Rl200S has been achreved without any spin-off sacrifice of midrange lorque, as on some of its twin-cylinder rivals. The Boxer motor pulls cleanly away on pan-rhrottle from as low as 2000 rpm in town or traffic, but there's a muscular, wide-open roll-on between 3500-6000 rpm which gives you a big kick of sacisfac' tion, and it made the BMW really fun to flde Lhrough a senes of twisnng turns up in the hills of the South African wine country You could hold a gear between turns and just work the throttle where you can feel the engine building power to its peak a lit- (le over Lhe 8000-rpm mark. Rewing rr right out to the 8800-rpm rev limiter seemed precry poindess. even if the engrne stayed smoorh and zestful at any revs. That's because (he refinements to the new mocor go far beyonO just makrng rr smoother, with the next big improvement vs. the R-Eleven the all-new six-speed gearbox made by Getrag to BMW's spec. This is now fitted with helical gears for slicker, more silent opemtion, as well as a comple(ely new system of gear selecrion incorporatinS sleeves and rollers rather than conventional forks - which comes straight from the world of Formula One. The new transmission allows you to shift gears without the clutch as a matter of course - some- thing previous- .a trock-dqy bike, it goes toword giving BMW o gportier imoge. olong / V \ D.l -/ -i{h - ,l't ' o \ I \! ( I l * I TL .l (r,. , ').r