The ultimate in bike design?

[skelstar]

One more day to live? Self sacrifice? I thought thats the kind of crap you talk about on a Friday when you're getting shit-faced with your mates...this is a motorbike forum FFS!

Anyway, I've often wondered what the ultimate is in sports bike design? Bikes seemed to be getting more powerful, lighter, shorter, and narrower every year. I think there must be a limitation but don't understand what they are...

POWER!!!
While I understand that its about how a motor delivers the power, there must be a limit on how powerful a bike can get (for any given chassis). Suzuki have brought out a bike that has a power limiting switch on the handlebars, which has been widely ignored by many ego-threaten males. I suspect no-one uses it. But...what are the limiting factors? Will bikes get to a point where they are unrideable? Or will suspension get so good it doesn't matter?

Weight
How light can a sports bike be? 25 years ago I bet the designers of the latest GSXR750 would have KILLED to shed 40kgs from their latest weapon. What do engineers want now? Is it reasonable to ride a 140HP (fig not accurate) sports bike that only weighs 130kg? What are the limiting factors? Roads are kinda rough, maybe longer suss travel on a lighter bike will help cope. There must also be an issue with the bike weight/rider weigh ratio too?

I'm no suss guru so i'm only guessing, but it does make me wonder. You'd def get to the balance point quicker eh? ;)

Size matters
Does it? Guessing again (but then thats the point of the thread): a super short bike is going to tip-in much quicker huh? ...but theres trade offs there too? Bikes getting narrower to have a smaller cross-section? There must be a limit here too. Engines sitting higher up in the frame for weight distribution...



So, whats the ultimate in sports bike design if weight-loss, power-limits, and frame-limits weren't the ...erm...limit?

[vifferman]

There have to be compromises made everywhere. The two main things that stop you being able to buy the ultimate sportsbike are cost and reliability. Race bikes are light and powerful, but are rebuilt after every race, and cost MEGA. Would you want to rebuild your engine after every ride? Would you pay $xxx,xxx for your perfect bike, and then pay as much every year to keep it running?

[Fatjim]

Given I'm not a motorcycle engineer I'm not going to comment or speculate. Carry on people.

[skelstar]

...cost and reliability...
Yeah ok, disclaimer: ignore cost and reliability. I'm just talking about ride-ability.

[imdying]

One more day to live? Self sacrifice? I thought thats the kind of crap you talk about on a Friday when you're getting shit-faced with your mates...this is a motorbike forum FFS!Damn skippy.

POWER!!!I suspect no-one uses it. But...what are the limiting factors? Will bikes get to a point where they are unrideable? Or will suspension get so good it doesn't matter?Totally agree... the human body will be the limiting factor (already is for most)... how fast your brain can react etc.


Weight
How light can a sports bike be? There must also be an issue with the bike weight/rider weigh ratio too?They'll keep getting lighter... as light as material pricing lets them... I'd expect to see more plastic parts, things like rocker covers etc. Bike/rider ratio shouldn't be a problem, they'll just have to spring and valve them differently.


Size mattersCan definitely see the engine size getting smaller, I'm picking that the average males body size will be the limiting physical size factor... North American males must already be about poked for riding sports bikes... probably a big reason why the Harley brand still sells so well, that and old people buy (for good reasons I might add, not a dig at cruisers).


Given I'm not a motorcycle engineer I'm not going to comment or speculate. Carry on people.Bollocks, you've commented in lots of threads that you're not qualified for, why the heck would you draw the line at one actually related to motorcycling??

/edit: Ha! Just realised... the limiting factor will be.... people!

[R6_kid]

Tyres... although not developed by the bike companies themselves, it comes to down to affordable technology... and im sure that you agree with me that any given bike is limited by two 'external' factors... the tyres and the rider.

If motorcycles were as important to the yanks as military arms are there would be far more development and far more 'thinking outside the square'...

Yes there are large sums of money being put into motorcycles... we get a new model 600 and 1000 every three or so years from the 'big four' Japanese companies, at the same time they are developing new technologies via MotoGP aswell. Compare this to 20 or even just 10 years ago. But think where we could be now if the Britten had recieved mass funding and was fully developed.

At the end of the day, motorcycles are techology, and technology is always changing. My thought is that motorcycles will be surpassed by some other technology in the future far before the very limits of performance are reached in the fullest extent.

[merv]

Agree with the comments of imdying and R6-kid in that I can see use of other materials coming into play. e.g. its taken a while but Boeing are finally coming out with the Dreamliner using a carbon fibre fuselage in place of aluminium. Sure John Britten was onto using this, the mass manufacturers just play it a bit more conservatively. I am sure it will come and weight can just disappear. Then what disappears as well is any fatigue limit issues associated with aluminium.

I can see other technologies coming into play like maybe gyro effect stabilisers, maybe GPS based guidance that prevents you ever running off a road so you follow the perfect line and all those kind of technologies.

I don't think its going to happen because of MotoGP because racing class rules restrict things quite so radical, like how they restrict weight, engine configuration, number of gears etc. The radical stuff will occur off in little research teams that produce the bike show prototypes.

Some of it will be driven by safety bureaucrats in the end too because I can see them calling for safety improvements that may radically alter the product we have enjoyed thus far.

[Bullitt]

There have to be compromises made everywhere. The two main things that stop you being able to buy the ultimate sportsbike are cost and reliability. Race bikes are light and powerful, but are rebuilt after every race, and cost MEGA. Would you want to rebuild your engine after every ride? Would you pay $xxx,xxx for your perfect bike, and then pay as much every year to keep it running?
Im not sure such concerns are relevant in a thread such as this.

Compare a brand new 600 production sportsbike, how far back would you have to go before that would be faster than a $xxx,xxx racing bike that needed rebuilt every race? 1980s? 1970s? There must be a point.

[riffer]

Not too far ago. I daresay the CBR1000R that Aaron Slight rode on the AA show two weeks ago had more power than his Superbike racer did.

[xwhatsit]

In terms of the power limit, do you remember when the original CB750 came out? I do, I was negative 19 years old at the time. Anyway, remember them talking about those 69 horses? How dangerous they were? Surely that was the maximum power that should be allowed on the road, any more than that was suicidal.

I'm sure there's a limit, but I don't think we're anywhere near it yet. Suspension's going to keep getting better to cope with it. Robert Taylor's got some fancy Öhlins going on, but we're not at the level that Formula 1 was in the 80s, with computerised active suspension, and we're yet to see any developments in producing active downforce. That will be something interesting when they solve that problem.

In terms of the human body being able to physically endure that amount of horsepower, nonsense. They've been talking about that in Formula 1 for years, that drivers couldn't cope with the G-forces/reaction times/mental calculation necessary to pilot themselves through Eau Rouge, yet Formula 1s are three metric shitloads faster than any motorcycle, in any sense of the word `fast'. It's interesting to also note that those super-fast 80s ground-effect/active-suspension F1s were bloody hard to drive; a present-day F1 is not only much faster, but a hell of a lot easier (and less likely to suddenly snap and end up leaving the track) than those 80s monsters. Same thing happens with bikes; compare our CB750 K0 with a Hornet 600. Roughly comparable horsepower and speed (is it? If not, substitute another similar pair of bikes). But with the Hornet you can mash the brakes without fear of unpredictable lock-ups, change lines in the middle of corners, predictably wind up the rear wheel without fear of high-siding, ride like a complete newb, whatever. In a few years we'll be riding 500s with GSXR1000-like performance, but they'll be as meek and rideable as a kitten (not that the GSXR1000, girl's bike that it is, isn't already :dodge:)

Formula 1 and other bleeding-edge motorsport has a hell of a long way to go before we start hitting these supposed hard limits, let alone motorcycles.

[xwhatsit]

Compare a brand new 600 production sportsbike, how far back would you have to go before that would be faster than a $xxx,xxx racing bike that needed rebuilt every race? 1980s? 1970s? There must be a point.

Owners of original RC164 1960s Honda 250cc GP bikes (and also replica makers) have for a while been dropping out the original, highly fragile four-lunged mill, and putting in a CBR250 lump instead. Apparently it makes identical horsepower at identical RPM.

CBR250 lump is about as reliable as they come, they withstand exceptional abuse.

1964 to 1986. 22 years, and I'd imagine that's on the high side (CBR250 was designed to stay below 45 horses, right?). Just engine technology too, major advances in suspension (mono-shock for starters).

[skelstar]

Ok:

1. Would you want to ride a 250HP sportbike in the guise they are in now?
2. Would you want to have a 100kg GSXR1000K7?

I guess this is what I'm getting at...

[merv]

I think I'd prefer option 2 provided the dynamics of the thing was designed to match. So that would be slightly lighter than my WR but with 4 - 5 times the power.

[skelstar]

I think I'd prefer option 2 provided the dynamics of the thing was designed to match. So that would be slightly lighter than my WR but with 4 - 5 times the power.
So what dynamics?

[merv]

So what dynamics?

Well being so light, suspension, any stability control electronics, frame geometry etc would have to be fantastic to make sure its not skittery, or get blown around in the wind too much and stuff like that. You wouldn't want one movement of the throttle flipping it on its back either, so it would have to have some anti wheelie device - maybe gyro like.

[craigs288]

I would like something like a Buell with the fuel in the frame, oil in the swingarm. But I want the tank (airbox cover) and seat and tail section as a one piece molded item. You could sit on a mold on the basic frame to get the ergonomics just right then have it made to perfectly fit your size/shape in the most useful/comfy position.
Everything carbon fibre for weight reduction and rigidity.
I have always enjoyed having vehicles with more power/torque than you can put to use most of the time. There's nothing disappoints me more than the feeling of 'I wish there was more'.
With that in mind, I think something like a injected 750-900cc four cylinder to keep the weight down, but with a centrifugal supercharger cranking out some serious boost.

[Ocean1]

Well being so light, suspension, any stability control electronics, frame geometry etc would have to be fantastic to make sure its not skittery, or get blown around in the wind too much and stuff like that. You wouldn't want one movement of the throttle flipping it on its back either, so it would have to have some anti wheelie device - maybe gyro like.

Traction control. The one thing that would make such a bike "safe" and able to get that power down to best effect would be that ability to sense a loss of traction faster than you can and control the throttle to modulate it.

It's actually quite do-able as long as the front wheel stays down, need that to compare road speed to back wheel speed. Sensor in the forks to read weight on the front wheel could work. Same system in reverse could be used for ABS although it'd be possible to confuse it by semi-locking both wheels.

Personally I don't see the point in more power than they've already got, where the hell can you use it, even safely let alone legally? Weight however is a useful target, and we're nowhere near what's possible there.

Production bikes are actually pretty conservative in terms of design, there's a lot of design constraints applied by the need to automate production to keep costs down. New and better materials are rarely used until ways are found to automate production. There's been low-volume specials available for ages that typically out-perform the latest showroom offerings, they just cost more because of the high labour content.

Occasionally a John Britten or an Eric Buell come along with a bunch of ideas which re-write the rules but by and large production bikes are a marketing excercise driven by a slow evolutionary process. We like to think the shiny new offerings are "cutting edge" but really they're nowhere near it.

[skelstar]

Personally I don't see the point in more power than they've already got, where the hell can you use it, even safely let alone legally? Weight however is a useful target, and we're nowhere near what's possible there.
Well, sure as shit the big bike manufacturers are spending lots of money finding ways to make them more powerful (with reliability/cost efficiency blah blah)... there must be a lot of people asking of more power.

Now, why is weight a more useful target?

[Mr. Peanut]

I always thought a variable wheelbase would be interesting, or more wheels inline.

[Mr. Peanut]

Buell... oil in the swingarm....

Unsprung weight?

[skelstar]

I always thought a variable wheelbase would be interesting, or more wheels inline.

Cool...why? :) ...grip? (wheels inline)

[Mr. Peanut]

Yeah more stability and grip, it'd be less prone to wheelies too. But I don't know much about motorcycle dynamics, so for all I know it could be an impossibility! :sweatdrop

I was thinking a small center wheel for putting power down and stability with the front and rear tires devoted to grip.

[Paul in NZ]

This has got to be as dumb as any other thread... There are no limits - just engineering and marketing problems - thats all there has ever been...

What defines a motorcycle? Say if I came up with a thing that looks like a bike and yet uses some kind of antigravity device to keep it off the ground is it still a motorcycle?

Technology changes and grows and with it grows the horizon of whats prossible / practical.

IMHO, Modern sportsbikes handle bloody awfully compared to (say) my old triumph. Its a 'natural' handler in that the bike is utterly instinctive to ride due to a low centre of gravity etc whereas a GSXR etc has to start making engineering compromises to keep it on the road under full power (engine mass is lifted higher etc) and then more engineering has to be thrown at it to make it go around corners and a slightly more technical and un natural riding style adopted.

Eventually - technology will have to make MORE compromises and the riding style will get more technical so some functions will get delegated to computers to make it useable (much like in a modern jet fighter) because the average human can't react in time.

There are no limits - except can I make it at a price that I can convince people to pay?

[skelstar]

This has got to be as dumb as any other thread...
Really?... I thought it was quite reasonable if you understand the intention of the thread.

I'm just curious to know what the limits are of the design of bikes. Super-light bike? Super powerful bike?

Its a damn shame KBers would rather wax on about their last day, saving the world, each others arse, relationships and how bad a day they're having. I'm attempting to provide an alternative.

[imdying]

Its a damn shame KBers would rather wax on about their last day, saving the world, each others arse, relationships and how bad a day they're having. I'm attempting to provide an alternative.Damn right... bunch of cock suckers.... wahhh wahhh I'm so depressed... wahhh wahh, I don't like the government... waahh wahhh lets all hug, what side of the bed do you sleep on, etc etc etc...


IMHO, Modern sportsbikes handle bloody awfully compared to (say) my old triumph. Its a 'natural' handler in that the bike is utterly instinctive to ride due to a low centre of gravity etc whereas a GSXR etc has to start making engineering compromises to keep it on the road under full power (engine mass is lifted higher etc) and then more engineering has to be thrown at it to make it go around corners and a slightly more technical and un natural riding style adopted.Dunno wtf you're smoking.... your Triumph's chassis doesn't get beat up by the power of the motor cause it's a gutless sack of shite....

[merv]

Hey be nice fellahs its Friday and we can all relax because the weekend is going to be good for riding and dreaming about the ultimate bike.

[limbimtimwim]

IMHO, Modern sportsbikes handle bloody awfully compared to (say) my old triumph. Its a 'natural' handler in that the bike is utterly instinctive to ride due to a low centre of gravity etc whereas a GSXR etc has to start making engineering compromises to keep it on the road under full power (engine mass is lifted higher etc) and then more engineering has to be thrown at it to make it go around corners and a slightly more technical and un natural riding style adopted.It's just what you are used to. Getting on completely different style of bike always feels stupid and 'wrong'. My DR felt ridiculous for awhile, now I can chuck it around with heterosexual abandon. A month on a modern GSXR and then back on to your 'umph, you'll be noticing how bumps upset it, that the brakes require effort, the fueling lacks precision, etc etc. At the race getting on my 400 feels totally stupid for awhile, all those revs, the hard suspension, totally incorrect.... For about 10 minutes. Then the riding postion is correct also.

[Ocean1]

Well, sure as shit the big bike manufacturers are spending lots of money finding ways to make them more powerful (with reliability/cost efficiency blah blah)... there must be a lot of people asking of more power.

Now, why is weight a more useful target?

They're making bikes with more horsepower because that's what sells. It sells partly because the marketing machine encourages people to consider that to be the most important quantifiable quality. So yeah, there is a lot of people asking for more power. I just question whether NZ roads are an appropriate place to use 200hp plus, no matter how good you are.

Weight is a more attractive target for me because the advantages of less weight flow into far more quality considerations than simple acceleration. Given similar geometry a light bike will not only accelerate faster it'll corner at higher apex speeds because there's less load on the tyres. Reduced weight design elements also have a sort of self-perpetuating outcome, the bike will use less fuel to do the same job, so it needs to carry less, which means it needs less mass to remain rigid, which means...

Also, I consider torque to be a more useful performance variable to target. Not only is it a more accurate descriptor of useable energy for the application but, (and again personally), I find bikes with high torque more fun to ride and more forgiving of mistakes.

[T.W.R]

Actually getting to try one of these puppies out would be enough without advancing anything on the design apart from the engine (the original powerplant is a 88' GSX-R750). Two wheel drive, two wheel steer, gyroscope controlled pivoting seat. It was way ahead of it's time in 1988 and even today there haven't been many bold enough to get close to it

[Conquiztador]

The main limiting factor has to be the small spot front and back that connects you to terra firma. If you are on gravel, grass or wet tar seal no matter how light, fast, well balanced, good suspension. You just lost the use of 90% of that plastic fantastic you have between your legs.

[skelstar]

That looks kinda cool, and not tooooo dated either.

[Bullitt]

Gonna be alot of suspension travel with that much ground clearance:rolleyes:

[Shadows]

Actually getting to try one of these puppies out would be enough without advancing anything on the design apart from the engine (the original powerplant is a 88' GSX-R750). Two wheel drive, two wheel steer, gyroscope controlled pivoting seat. It was way ahead of it's time in 1988 and even today there haven't been many bold enough to get close to it

You'd need to get some leathers that looked like this though...

[T.W.R]

You'd need to get some leathers that looked like this though...

:laugh: Ideal for the local TRON convention huh :shutup: though the grid elimination game would be interesting

[Forest]

As an enthusiast, I think the biggest problem with modern high-performance sport bikes is their sophistication. Which is ironic given that it is also their biggest advantage!!

I would personally love to have a modern high-performance sports bike that would still be rideable in 25 years time. However I don't think that is likely to be possible. The advances in engineering science and technology mean that modern high-performance bikes have become almost irreparable.

Of course you can replace broken parts in a modern bike, but very often you cannot repair the broken back to the original factory specifications. Once the parts for a particular model get hard to find (and this will happen eventually) then the bike's owner will be screwed.