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01-16-2008, 11:04 AM
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Fighting for the Yamaha spotlight with the new Star Motorcycles Raider is a revised YZF-R6 sportbike. But the tuning-fork brand has also unveiled two small-bore streetbikes (a supermoto machine and a similar dual-purpose 250), plus a heavily tweaked XT225 that jumps to the status of XT250.
But the big news is the made-over R6. The previous R6 tied for second in MO's 2006 middleweight shootout behind the Triumph Daytona 675, but it has stiff competition in this class, not least of which is the stellar '07 Honda CBR600RR. To gain a leg up, the Yamaha screamer has received a myriad of updates to its engine and chassis.
Starting off in the engine room, Yamaha engineers have thrown the R1's variable intake system at its lil' bro R6. The Yamaha's Chip Controlled Intake (YCC-I) varies the length of the intake snorkels depending on rpm to broaden the range of usable power, which is something the peaky R6 really needs. As before, an EXUP exhaust valve works similar magic on the outlet side through a MotoGP-styled titanium muffler. More titanium is found in the intake and exhaust valves, and lightweight magnesium is used for its engine covers. Yamaha claims to have made some 50 refinements to the engine for a reduction of internal friction, including wider crankshaft bearings, and the compression ratio gets a bump from 12.8:1 to 13.1:1.
More: 2008 Yamaha Street Preview (http://www.motorcycle.com/manufacturer/yamaha/2008-yamaha-street-preview-66204.html) on Motorcycle.com
Fighting for the Yamaha spotlight with the new Star Motorcycles Raider is a revised YZF-R6 sportbike. But the tuning-fork brand has also unveiled two small-bore streetbikes (a supermoto machine and a similar dual-purpose 250), plus a heavily tweaked XT225 that jumps to the status of XT250.
But the big news is the made-over R6. The previous R6 tied for second in MO's 2006 middleweight shootout behind the Triumph Daytona 675, but it has stiff competition in this class, not least of which is the stellar '07 Honda CBR600RR. To gain a leg up, the Yamaha screamer has received a myriad of updates to its engine and chassis.
Starting off in the engine room, Yamaha engineers have thrown the R1's variable intake system at its lil' bro R6. The Yamaha's Chip Controlled Intake (YCC-I) varies the length of the intake snorkels depending on rpm to broaden the range of usable power, which is something the peaky R6 really needs. As before, an EXUP exhaust valve works similar magic on the outlet side through a MotoGP-styled titanium muffler. More titanium is found in the intake and exhaust valves, and lightweight magnesium is used for its engine covers. Yamaha claims to have made some 50 refinements to the engine for a reduction of internal friction, including wider crankshaft bearings, and the compression ratio gets a bump from 12.8:1 to 13.1:1.
More: 2008 Yamaha Street Preview (http://www.motorcycle.com/manufacturer/yamaha/2008-yamaha-street-preview-66204.html) on Motorcycle.com