I've not read a group test for yonks so don't know how the big 4 compare these days, but in an idle moment of curiosity, I just had a Google & found http://www.gixxer.com/forums/showthread.php?t=223205 I find a few things somewhat surprising: 1. Fireblade has most power & highest top speed. 2. R1 roll-on - fastest 30-50 but slowest 50-70 - but only by a tenth of a second (isn't that what the fancy crank's meant to be all about?). 3. R1 over 6mpg worse than the others. 4. On paper, the ZX10R is somewhat outclassed. Of course in reality the figures are all close enough that most people would never be able to tell the difference, apart from maybe the fuel economy. Be interesting to ride them all back to back though. -- Krusty '03 Tiger 955i '02 MV Senna (for sale) '96 Tiger (for sale) '79 Fantic Hiro 250 (for sale) '81 Corvette (for sale)
Not my understanding. AIUI, it's about traction and throttle control at high engine revs. And 'using GP technology' and sounding different. Does it have a balancer for the odd crank? CBA to Google. If so, that would sap a little power.
Sure, the uneven firing would give the big bang effect and at first I thought that was all it was about. I figured that any other effects would perhaps be indirect; for example, the powervalve broadened a 2T's power band, and in so doing allowed more extreme exhaust port timing and expansion chamber tuning without making the bike unrideable, so ultimately gave more power. The big thing that Yamaha claim (well, Journalists claim that Yamaha claim) with the new long-bang design is the ability to have V-4 timing in an inline-4 package, so you have the simple engine layout that makes it easy to have a short wheelbase, or more control of where the CofG is, and arguably the layout is easier to tune for higher power (but Ducati seem to do OK), but you retain the uneven firing and thus reduce the big crank angular accelerations at high revs, which apparently become very significant at the sort of revs a GP bike makes. This means that the peak forces on the rear tyre are less to do with throttle control and much more to do with revs; if a rider feels the back spinning up there's less he can do about it instantly on the throttle because it's much more a function of the engine revs. Well, that's how I understand it. Well, I was thinking fuel consumption, but I snipped that bit by mistake. I sure as hell wouldn't. I guess it comes down to what *feels* exciting and simply fun to ride, and from what I gather from the 10R owners here, that's what it's got.
Err, no. You're talking about the forces coming purely from the firing pulses, though, yes? My understanding is that the Yamaha solution isn't just about a 'big bang' engine, though that may be part of it (interestingly they specifically call it a 'long bang' engine, which implies less overlap), but about the inertia forces at 2x crank 'frequency' (I think they call these second order vibrations) caused simply by the acceleration of the reciprocating masses. If I've understood it right, at GP bike engine revs, they start to become significant but the 90deg crank pretty much eliminates them. The gist of this was in a Bike magazine article, though I guess that I and / or the journalists got it wrong. Prace bets now!
