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Old 03-19-2001, 05:22 AM   #61
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Default Re: Thank You Azrifel

Your right on the Money with the first statement but man you lost your mind with the 2nd.

They use twice the displacement because they need it. Just like they do in the dirt. 250's run with 125's and 500's run with 250's. The 4-strokes are much more fuel effiecient but to achive this they become much heavier, carry much more frictions and with all the extra moving parts simply don't make as much power as the 2-strokes which is why they are given a displacemnt advantage. It has very little to do with popularity. If the 4-strokes were restricted to the same displacement they would never in a million years produce enough power to keep up with the 2-strokes.

They are given the displacement advantage because people behind the 4-stroke movement want to succeed and they now this won't happen without a displacement advantage. Same concept behind the twin 1000cc's running with the inline 750's.
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Old 03-19-2001, 05:37 AM   #62
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Default Re: As stated earlier....

Two strokes fly off the shelves? I guess that is why all the Japanese except Yamaha dropped their two stroke bikes in the US BEFORE the EPA rules made it hard (but not impossible) to build street legal two strokes.

Remember the RZ 350 (US name, I think they still used RD350 outside the US) gosh, they sold so well they lasted all of two years.

Face it folks, regardless of what you want two stokes sell poorly everywhere and don't sell at all in the US. Even in places without environmental restrictions the only new two strokes are mopeds and scooters. Pick your term, p*ssing in the wind, trying to stop the tide, whatever, that is what you are doing, two strokes are dead.

BTW, I was the hardware store yesterday, I spoke to a guy buying a FOUR STROKE weed trimmer. He has owned two stokes, he was really happy, no mixing gas, no smoke, no shrieking two stroke. Same thing with my brother's sailboat, he was very happy to get rid of the two stoke and put a quiet, easy to start, clean four stroke in his engine well. Looks like two strokes aren't just dead for bikes.
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Old 03-19-2001, 06:19 AM   #63
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Default Re: Competitive with who?

Um... no and no.

I think the other guy said it right. The lap times are currently very similar between WSB and GP bikes, and the GP bikes are significantly lighter. It's not that the factories cannot make the WSB bikes lighter (or so I've read), it's just that their rules set a higher min weight limit. Logic would state that if you took a current WSB bike which is running times close to those of GP bikes, and, keeping all other factors equal, dropped ~100 pounds from it (or added that weight to the GP bikes), it would likely circulate even faster, presumably faster than current GP bikes.

I'll grant you that smaller engine generally implies less weight (all other things being equal), but that definitely does not imply "more speed". Once you get above 120mph or so, speed has very, very little to do with weight... it has everything to do with power and aerodynamics. Acceleration is about power and weight and traction.

Circulating a given track quickest is about so many factors, we cannot possibly discuss them all here. Weight is certainly a major factor, but suffice it to say that it is by no means the only factor.

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Old 03-19-2001, 07:20 AM   #64
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Default Re: Yamaha Officially Releases OW-M1 Details

We're trying to get hold of him right now, actually...
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Old 03-19-2001, 07:37 AM   #65
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Default Brilliant!

Thank you Dirtbiker for spelling it all out so logically. I hope this is the end of the 2 vs 4 stroke debate here, lets just embrace the 4 stroke future and move on.
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Old 03-19-2001, 08:19 AM   #66
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Default Re: You

Don't count on it. With the strength and power of the environmental lobby growing daily, plus the manufacturers putting more and more money into 4-stroke R&D, the days of the 2-stroke are limited. I agree wholeheartedly with the advantages of the 2-stroke in racing, but to think that they will be around much longer, even in racing, is just not being realistic. Hell, I even have a 4-stroke weed-wacker now!
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Old 03-19-2001, 11:59 AM   #67
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Default Re: It is well known...

If we are to compare the pinacle of 2-stroke technology (500cc-GP bikes) with the pinacle of 4-stroke technology (F1-engines) we find:

2-stroke 500 cc == ~200 Hp == 400 Hp/litre

4-stroke 3000cc == ~830 Hp == 275 Hp/litre

Therefore, in an equal cc formula 4-strokes are dead meat.

However, the modern rules allow 4-strokes 990cc

giving them a clear advantage in max power (270 Hp to 200 Hp) and thereby a clear advantage in top speed, a clear advantage in low end throttle response, and a moderate disadvantage in weight. Sounds like a thrilling forumla to me.

With 1 litre road bikes comming in at 150 RWHp, it donesn't take much imagination to see that a race-only engine design could easily match the 500cc 2-strokes, even without the F1-like pneumatic valve train, and exotic engine controlers.

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Old 03-19-2001, 02:02 PM   #68
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Default Re: MV Agusta what?

Racing is about limits. In GP these days the machines are very close in performance (to each other) and the winner is the budget that gets you the closest to perfection with a good pilot. A new design brings different limits to the game.

You 're right about the extra cylinder, more friction, more moving parts, etc. But they are smaller and lighter moving parts than in a 4-cylinder engine, witch allows higher rpm. About the vibrations, a well balanced V engine produces less vibrations, lasts longer, is more comfortable and sounds better. We 'll see if it works, but in theory it 's great.

Yamaha is probably focused only on winning (that's why they use the "known" concept), but if Honda sees a future on the road with the V5, it certainly will not stay 820 cc. Can you imagine a 1200-1400 cc V5 engine on a sportbike? I can! And I love the idea.

So you don't like the aggressive black streetfighter look? HmmÂ… Then you must be a very peaceful person that hasen't hated many things in his life. Haha you don't see that very much in Europe.

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Old 03-19-2001, 03:52 PM   #69
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Default Re: Competitive with who?

i can't believe you people would actually post your comments here knowing as little as you do about racing motorcycles. grand prix motorcycles have been built from the ground up to be the very fastest things on 2wheels around a racetrack. they have nothing in common with streetbikes, unlike WSB bikes. they are lighter, yes. but they are also much more powerful - more horsepower and more torque. their carbon-carbon brakes are superior. their aerodynamics are superior. everything about them is superior. Ben Bostrom turns one very quick lap, and people who don't know SH1T are already proclaiming WSB to be as fast as grand prix. let me correct you now, lest you say something idiotic in front of someone in the racing world who actually knows the truth, like Ben Bostrom
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Old 03-19-2001, 04:00 PM   #70
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Default go stand in the corner, you dunce

um, lets see now:

same horsepower


but one ways less than the other


they're both as fast as each other


you are a know-nothing dumbasss
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