2-strokes in MotoGP?

[Mental Trousers]

So are you saying they wouldn't have come along if there wasn't 2-strokes racing in GP's? Its all the same arguement, you are always going to get development on what is there. Boil it all down and your still working with a internal combustion engine (2-stroke or 4-stroke) that runs at somewhere between 20-30% efficiency.

Boil it all down and cc for cc a two stroke will waste a fourstroke...fact.

Problem is these days it's all about extracting as much as possible from a given amount of fuel not a given engine size. Four strokes are quite a way ahead in that regard unless you move to Direct Injection Two Strokes, then they're pretty much even.

Ok, so lets say, pneumatic valves, slipper clutches (or electronic engine braking), multiple engine mapping accessable on the fly, ect ect. Yeah, a lot of electronics there, but lets be honest, thats the way the world is going. (And yes, I am one of that generation who has never bought a newspaper.)

Your world=extra weight,extra complexity and extra expense...proven fact if the last ten years has meant anything.

Interestingly if you look at consumer transport in general the amount of shit that gets lumped onto a vehicle design in the name of efficiency, features, driveability, safety and comfort negates any weight advantage the two stroke has. If it's not going on the road the manufacturers aren't going to develop it on the race track (there are noteable exceptions like pneumatic valves etc and I'm not sure how they justify developing those).

[mr bucketracer]

APART from electronics, as these can be used on both 2 and 4 stroke, what has the fourstroke bought us development wise that's that much different than say the 1960's? Still four valve ( poppets ), still twin over head cam, still require many revs to make power ( BMEP is still much the same, just at a higher RPM ). Parts are lighter, a little less internal friction ( special coatings ). Not much excitement there!
Twostroke development was just getting started but the rules soon took care of that!
I think perhaps the " manufactures" didn't like the idea of modifying your twostroke with just a die grinder and a few clues. Fourstroke's are far more profitable to hot up with all that stuff, cams, valves, springs, pistons, etc, etc. The more you spend, the shorter the fuse.
The only fourstroke I have in my shed is sitting there waiting for it's 50hr piston change and I just can't get excited about it! I'd rather ride my "dirty old twostroke", way more fun.

at the end of the day most bikes on the road are 4 strokes, guys that liked 4 strokes did not get to see gp 4 stroke racing for years when 2 strokes took over , injection was hardly out , traction control , running engines backwards ,making engines last longer , fuel tank sizes . l would of liked to see them race together .. maybe best was to limet fuel and run any size engine because thats what its about fuel aconomy and also how long engines last well thats what i think

[Flettner]

Problem is these days it's all about extracting as much as possible from a given amount of fuel not a given engine size. Four strokes are quite a way ahead in that regard unless you move to Direct Injection Two Strokes, then they're pretty much even.

Are you sure about that? Where do you get your facts? Twostroke has a lot less crap to turn over, I think you will find Rotax DI twostroke snow engines have been shown to be better in every way than the fourstrokes they compete with, including emissions and fuel economy, that's still just a loop scavenge engine.
Also indirect injection ( rear transfer port ) has been shown to burn approx 20% less fuel than a standard twostroke under the same riding conditions, same top end power. Dyno tested.
Twostroke's looking pretty good

[tail_end_charlie]

So are you saying they wouldn't have come along if there wasn't 2-strokes racing in GP's? Its all the same arguement, you are always going to get development on what is there. Boil it all down and your still working with a internal combustion engine (2-stroke or 4-stroke) that runs at somewhere between 20-30% efficiency.

Boil it all down and cc for cc a two stroke will waste a fourstroke...fact

Correct, not arguing that point. Any dummy should know that a 2-stroke has a better thermodynamic efficiency then a 4-stroke, the big drawback being that they are not as clean burning. (and yes that is relevant in today's world, sorry) Your original post below.....

Afterall the two stroke era gave us radial tyres,decent frames and suspension,powervalves and by association exup exhaust valves that all manufacturers adopted,radial braking and big bang crank timing...I could go on.
The modern four stroke era has given us...um...er...5 valve heads are all shit...um...er 990's are to dangerous...um...er 800's are to boring...um...er oh yeah electronic control to take the guess work out of riding skills.

..................are you trying to say that the only reason that we had any developments in motorcycle technology is due entirely to 2-strokes racing in GP's? If the 2-strokes had never come around and they raced 4-strokes do you think that there wouldn't have been any advances in frame technology, radial tyres, suspension, radial brakes, ect?

Ok, so lets say, pneumatic valves, slipper clutches (or electronic engine braking), multiple engine mapping accessible on the fly, ect ect. Yeah, a lot of electronics there, but lets be honest, thats the way the world is going. (And yes, I am one of that generation who has never bought a newspaper.)

Your world=extra weight,extra complexity and extra expense...proven fact if the last ten years has meant anything.

And I would imagine that the generation before you would say the same thing about alternators vs generators, magnetos and points ignition systems vs electronic ignition, carbs vs FI, and on and on and on. Anyone who sticks their head in the sand to ignore advances in technology will get left behind. The more you use technology, the more it gets refined, the more robust it becomes. Sure the modern cell phone is a lot more complicated than an old radiotelephone, but which do you use?

Probably about as many as large bore (greater than 125cc) 2-stroke engines that have been sold recently...........actually, probably less. (Talking road bikes specifically, not off-road)
Even when 2-strokes were the king of GP racing, what was the ratio of 2-strokes vs. 4-strokes that were available to the public? I've been to a couple of classic bike show and swap meets, and the majority of bikes I see are 4-strokes. So it seems that the argument that the MSMA made for 4-strokes being more relevant to the consumer is correct........

^^I'm sorry, I must have missed you response where you told me just how much more relevant a twin, counter-rotating crank V-4 2-stroke engines were to the run of the mill production bike that mere mortals could buy from their local dealer????

Bottom line,GP racing used to be about going from point to point faster than the next guy.Now it's about selling product,be it roadbikes or TV packages.

Yeah, because AJS, Aprilla, Derbi, Ducati, Garelli, Gilera, Kreidler, Harley Davidson, Honda, Kawasaki, Mondial, Moto Guzi, MV Augusta, Norton, Suzuki and Yamaha never got into racing in the first place to sell bikes. Right? I hardly think so. It's always has been, and always will be, about who goes fastest on WHICH bike.

Now go back to the top of page 6,make yourself a nice cup of tea and start reading again...then get back to me when you've got a clue.

Your turn................

[tail_end_charlie]

So as I drove to work (its ok I had some bike parts in the van) I didn't see any open wheel driver exposed cars revving to 20,000 (or whatever tehy do I care not about car racing).

Good point, and I hear next year they are going to turbocharged V6's, and we also never see any turbo-charged V6 powered cars out there either....................oh wait.

I think you will find more similarities between the fundamental design principles (engine, EMS, braking, suspension, ect ect) of a F1 car and a modern sports car then you would between a 90's GP bike (2-stroke) and a 90's sports bike (majority of which were 4-stroke).

And I'm glad you brought up cars, because if 2-stroke engines are all so much better than 4-stroke, then why didn't we ever see 2-stroke cars everywhere???? Are ya'll trying to say that Honda has so much influence over the world that they decided they didn't like getting beaten in GP racing, so they made sure every automotive industry in the world went to 4-stroke???? Cause that would be one hell of a conspiracy theory. That may just be enough to get you committed..........

[tail_end_charlie]

So that's who's stealling them. You probably have it away with me milk money too (its hard to buy tokens these days, mind you the milkman seems to have skipped us. . .- well for quite some time now. I'll send him a fax).

A fax!?!?! Holy shit! You're using modern technology!!!!! I would have thought you were still using a fire and a blanket to throw up smoke signals............

[husaberg]

I think you will find more similarities between the fundamental design principles (engine, EMS, braking, suspension, ect ect) of a F1 car and a modern sports car then you would between a 90's GP bike (2-stroke) and a 90's sports bike (majority of which were 4-stroke).

Seen a NSR250 Honda and a Early 90s RS250?
Or a RGV250 and a RGV250 GP bike
The Yamaha's 250's were even closer.....

[tail_end_charlie]

Seen a NSR250 Honda and a Early 90s RS250?
Or a RGV250 and a RGV250 GP bike
The Yamaha's 250's were even closer.....

What were the numbers though? Lets say a comparison of production numbers during the 90's between 2-stroke bikes and 4-stroke bikes? I know that there were production GP replica's put out there, but what were their numbers?

(I may have shot myself in the foot there, cause I don't actually know........)

And for the record, I've never seen many of the 2-stroke bikes up close...................they'd all been blown up by the time I got into bikes..............................

[Flettner]

In reality it's a great situation, no twostroke road bikes available to choose from. It makes for a good market for smaller manufactures ( specialist ) to produce perhaps two and three cylinder road going bikes, fuel injected. Light and fast and most of all, DIFFERENT! You might find there is more interest out there than you might think.

[Mental Trousers]

Are you sure about that? Where do you get your facts? Twostroke has a lot less crap to turn over, I think you will find Rotax DI twostroke snow engines have been shown to be better in every way than the fourstrokes they compete with, including emissions and fuel economy, that's still just a loop scavenge engine.
Also indirect injection ( rear transfer port ) has been shown to burn approx 20% less fuel than a standard twostroke under the same riding conditions, same top end power. Dyno tested.
Twostroke's looking pretty good

You'd have to point me to the stats that compare the Rotax 800R E-TEC to a four stroke of comparable performance in a similar application cos I haven't been able to find any. It'd have to be something like a 750-850cc four cylinder otherwise you're not comparing similar specs, ie similar power outputs to see the difference in fuel consumption etc.

[husaberg]

What were the numbers though? Lets say a comparison of production numbers during the 90's between 2-stroke bikes and 4-stroke bikes? I know that there were production GP replica's put out there, but what were their numbers?

(I may have shot myself in the foot there, cause I don't actually know........)

You did, as they were huge sellers in their market segment......sports 250's.
I would also hazard a guess there survival rate is actually higher than their expensive to fix 4 stroke brethren as well.

AS for 4T vs 2T sales pointless...... ever wondered what the biggest selling bikes are in NZ......

[steveyb]

And I'm glad you brought up cars, because if 2-stroke engines are all so much better than 4-stroke, then why didn't we ever see 2-stroke cars everywhere???? .

Here ya go....

http://en.wikipedia.org/wiki/Suzuki_Fronte

My mates family had a 7S-SS10. Bloody neat it was.


Well, I guess they aren't quite everywhere......

[roogazza]

What were the numbers though? Lets say a comparison of production numbers during the 90's between 2-stroke bikes and 4-stroke bikes? I know that there were production GP replica's put out there, but what were their numbers?

(I may have shot myself in the foot there, cause I don't actually know........)

And for the record, I've never seen many of the 2-stroke bikes up close...................they'd all been blown up by the time I got into bikes..............................

It seems you are one or two eras ahead of some of us ? I'm sure you would have loved ours.
I started in 1965 on a new 80cc TwoStroke Yamaha, never owned a 4T.
Graduated whole heap of 250s,350s,400s,500 lastly 750cc triple in 1972 ! All 2Ts.
4Ts from 85 onwards. 50 bikes!
Imagine what you'll be riding in your sixties ? or if ?

[F5 Dave]

Here ya go....

http://en.wikipedia.org/wiki/Suzuki_Fronte

My mates family had a 7S-SS10. Bloody neat it was.


Well, I guess they aren't quite everywhere......

Same model as a mates. Golly was it 30 years ago.
Reputed to be so small you could have driven it through the botanical gardens pathways in the small hours. Not that it ever happened of course.

[tail_end_charlie]

It seems you are one or two eras ahead of some of us ? I'm sure you would have loved ours.
I started in 1965 on a new 80cc TwoStroke Yamaha, never owned a 4T.
Graduated whole heap of 250s,350s,400s,500 lastly 750cc triple in 1972 ! All 2Ts.
4Ts from 85 onwards. 50 bikes!
Imagine what you'll be riding in your sixties ? or if ?

Ha ha, yeah, I think there may be a few gens between us.
Grew up in the States following Dad around to bike shows and swap meets and stuff, but it was almost all classic American or European 4-stroke stuff. Never had much if anything to do with 2-strokes, other than cursing chainsaws.

And granted, the 2-stroke era may have been great and all, but I get a bit pissed off when people talk about it as the end all and be all, and their ain't nothing good that has happened since they got rid of the smokers. Different perspectives........