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 matters

Can 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:Me]

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 )

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.