Article: What now for the power race?

[Silver]

Another article I've written for the site...
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When the latest sportsbikes hit these shores and the magazine reviewers have had time to ponder, write and print their tests there are a couple of questions people want answering when they read the review: how much power does it have and how fast is it? But with speeds rapidly approaching the double ton and bike power exceeding that of the normal 'hot hatch' car, are these the most relevant questions?

Background
The release of Suzuki's GSX-R750 in 1985 was a turning point for sportsbikes. This was a bike that made people feel like their GP racing heroes on the road. A year later a bigger brother followed in the guise of the GSX-R1100. This proved to be a bike that would gain cult status, if not least for its unburstable engine. 126bhp as standard may seem unremarkable by today's standards but the engine had such tolerances that tuning it was easy and big power gains commonplace. If the GSX-R1100 had an obvious Achilles heel then it was the chassis and lardy 237kg weight.

Now jump forward twenty years and you have the 1100's natural successor in the shape of the GSX-R1000. Although progression has meant the loss of some 75cc in capacity, this has done nothing to dampen its ever increasing search for more power. Where the old 1100 produced 126bhp, this one makes 176, a 40% power increase. Weight is down to a staggering 166kg. What this means, in real terms, is that the current flagship sports Suzuki makes 1.06bhp/kg compared with its ancestor's 0.53bhp/kg. What we're taking about here is the current model having twice the power to weight ratio of the original. And the original was considered a beast. This is without considering the newer chassis and components that transmit that power more efficiently.

Given the large capacities of the GSX-Rs mentioned above now consider the current GSX-R600. Producing around 110bhp from 161kgs makes for a 0.68bhp/kg power to weight ratio - still more than the original GSX-R1100. The current Kawasaki ZX-6R makes similar power from slightly less weight and the same is true of Honda's CBR600RR and Yamaha's YZF-R6, give or take. This shows a trend of increasing power and decreasing weights, and you don't have to go all the way back to the mid-80s in order to make the comparison. The ZX-6R debuted in 1995 with 98bhp and a weight of 182kgs. In a little over ten years there's been a 10% increase in power and a 14% drop in weight. And this is from a small capacity sports bike where power gains are generally harder to achieve.

Now look in the other direction at the hyper-sports bikes; the large capacity, mile-eating, top speed monsters. You only have to take a glance at top speed and 1/4 mile drag events to see that the weapons of choice are Suzuki's GSX-1300R Hayabusa and Kawasaki's ZX-12R. The Hayabusa has remained largely unchanged since its introduction in 1999. Its 1300cc power plant produces 163bhp and although it weighs 215kgs, it is designed for top speed which means you'd see it hitting around 186mph in standard guise. It's not like the weight hinders acceleration either as 1/4 mile is despatched in a little over ten seconds from a standing start. Similar figures are true of the ZX-12R. Indeed, it was a gentleman's agreement that saw the 'big four' Japanese manufacturers restrict the top speed of their bikes to 186mph (300kmh) amid growing noise from politically correct forces about their quest for the coveted 'fastest sportsbike' mantle. Look back at the top speed events and you'll see these bikes, adorned with modifications, clearing 200mph on a reasonably regular basis.

Where does it end? At what point does it become impossible, in practice, to pull more horsepower from less weight? When bikes like the Honda Fireblade came along in 1992 they redefined the era in terms of power, weight and handling. This was a nutter's bike and it was hard to see at the time how it could be bested. Evolutions of the model continued for a few years, but no-one really recreated that 'wow' factor, or jump in performance... until 1998 when the Yamaha R1 exploded onto the scene. Once again things had leapt forward and the R1 was all the bike you could ever want, or need etc. A couple of years later and the GSX-R1000 dropped onto forecourts and you were left with a feeling of deja-vu. Once Kawasaki got round to replacing the ageing ZX-9R with the lighter, more powerful, nimbler ZX-10R you could have been forgiven for wondering where it would all end. The current model gives around 1bhp per kilo, a stonking 85ftlb of torque and (with the other litre bikes) a top speed in excess of 180mph.

A similar article on a car website would have been obsessing over 0-60mph times long before now and the reason we haven't here is because it's largely irrelevant. A decent 400cc sports bike from the mid-90s will beat 99% of cars away from the lights and a 600 will murder them. But here lies the problem. An outdated 400cc bike (or 250cc two stroke for that matter) will hit 60mph in around 4 seconds which is about the same as a £121,000 Lamborghini Gallardo. The 400cc bike would have around 60bhp. Now imagine one with the same weight (the design for 400cc sportsbikes is probably 15 years old), and two and a half times the power, with a better chassis, suspension etc. Does this mean the 0-60 is going to be 1 second? Of course not. There is a practical limit to the speed with which a bike can get off the line, due in no small part, to resultant factors such as wheelies and wheel spin. So, as power has continued to rise and weight has dropped we still see the 0-60 times hovering around the 3 second mark. What is more important, and more relevant, is the standing ¼ mile time. There are standard road bikes that knock on the door of 10 seconds - the mythical figure used by serious car tuners et al and mentioned to death in films like The Fast And The Furious.

The future
So where now? It could be argued that we've reached the limits of low-down acceleration and have achieved acceleration over ¼ mile that would cost car drivers tens of thousands of pounds (the Gallardo is over 12 seconds, by the way). ¼ mile is not very far, maybe we need more acceleration over that? Well, since you're likely to do doing 140mph+ by that point on a 10 second bike then I think the police would be inclined to disagree.

Interestingly, a Japanese technician was recently interviewed during the release period of the new 2007 GSX-R1000. He stated that their focus was shifting from speed and power to less quantifiable attributes (on paper), such as making the machines more usable. What use is all this power if you can't use for fear of being spat over the handlebars? He said that we were close to the practical power outputs and (new metal discoveries or developments aside) very close the weight saving limits.

What is more interesting is that the new GSX-R comes with a three-way power toggle, effectively giving you an instantaneous switch between roughly 180bhp, 150bhp and 120bhp. The idea is that for track days etc you'd use the full fat version, switch to 150bhp for normal road riding or 120bhp for rainy conditions. And it's done in engine management, not by disabling parts of the engine. Very clever and proof that they're looking past the sheer numbers and at ways of making the bikes more usable in the real world. It might also help you stop shredding rear tyres, chains and sprockets on such a regular basis too. Suzuki are not the first manufacturer to employ this idea, but they are on a top-selling litre sportsbike in an industry still obsessed with power and outright speed.

Conclusion?
You could be forgiven for reading this and thinking that I'd back some ridiculous EU motion that limited bike power or speed (like the one that surfaced a few years back trying to limit bikes to 100bhp). If that's the case then you couldn't be further from the truth. In reality I'm very much against censorship for adults in most walks of life, be it bikes, films, freedom of speech or whatever. I have a bike that'll top 170mph and I should be trusted to understand the potential consequences of doing that speed. What I would like to see, and I think the only way it can start to go, is for manufacturers to make the bikes better, rather than just faster. I'm talking about ideas like the GSX-R1000's power switch, increasing the torque (something you can never have too much of) and putting some thoughts back into being innovative.

I can't believe anyone will buy one 600cc sportsbike over another because it does 163mph instead of 160mph, so they need to think of other ways of making their bike attractive. Do we need another 10bhp, another gimmicky way of routing the exhaust or genuinely innovative additional features? I'll choose the latter, given the choice. Who knows, maybe I'm completely off the mark and sound like a reviewer from the 80s, whilst we're only round the corner from bikes that will do 200mph out of the showroom. Only time will tell.

[craigs23]

An interesting read.

I have given up the race for power, seeing anything over 100bhp unuseable, or rather, unrealistic to fully (and sort-of legally) able to use on the road. (Irish Road Racing, epsecialy the smaller classes, shows what a relatively underpowered bike is really capable of on the road).

Owning one of the machines mentioned (no guesses needed for which) made me realise that I can try to use what the bike's got, but ultimately, I'd never be able to, wouldn't want to persist in trying to on the road and left me unsatisfied on "failing" to. I'd rate myself as a pretty average Joe Bloggs road rider. But enough about me...

I don't think I've seen a massive revolution of the sportsbike flagship class since the 1992 Blade - everything else just seems to be continuing the trends set.

More useability/fun/innovation please.

[McGee]

[craigs23]

Different, but hardly class redefining/trend setting.

However, it would be the 'middleclass' bike I'd opt for out of what's on offer.

[twpd]

[McGee]

[Silver]

[craigs23]

And is most likely more useable/just as fast as the thou?

[Silver]

I would think so. I've ridden the K4 Thou and whilst the acceleration was impressive I hardly need more than the 750 gives. I'd be quite wary riding in rain/ice/snow too!

[Kickstart]

Hi

The original GSXR750 more defined things for its weight rather than its power. It wasn't that great for power (easily bested by the FZ750), and the weight was possibly taking things too far (you could bend the wheel spokes on the original GSXR750 with your hands). Indeed, while the GSXR750 gained power over the year, it also gained weight for quite a while.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Silver]

I wasn't making reference to the 750 for its power, just really that it was the first GSX-R. The references to power begin with the 1100.

[Kickstart]

[Danny]

I agree that there needs to be more innovation in bikes.
Which is part of the reason I bought my K1200R, which has more innovative features than I can remember.
But unfortunately BMW went a little too far and started innovating for the sake of innovation,
e.g. adding an electronic brake servo which is completely unnecessary given the performance of modern unassisted brakes.
It is also prone to indirect failure as I've found out.

They hit the mark imo with the duo-lever front suspension though, works very nicely.
Other innovative features I like:
Shaft drive that can handle 170bhp+
Cylinders banked at 55 degrees (lowers centre of gravity)