How fast is a supercharged Kawasaki H2? BikeSocial members find out

It starts with a sound. The shrill, high-pitched shriek has dogs’ ears pricking up as a small black dot appears on the horizon, shimmering in the heat haze like a tiny mote of dust dancing in sunlight. Within a few seconds the noise – it’s the sound of air being torn apart inside a spinning compressor and spat from an exhaust – deepens into roaring whistle as the dark speck resolves into the shape of a bike, pointed nose, rider prone on the tank. The machine flashes past, quick as your eyes can follow, its velocity shrinking the concrete expanse into a narrow strip. A speed flashes up on the digital box by your feet – 200.019mph, the double ton, or 293 feet per second – just over three-quarters of a full-size football pitch. In one second. Some people take longer to blink. So to the question of how fast is a supercharged Kawasaki H2... the answer is fast. Plenty fast.

How fast is a supercharged Kawasaki?

BikeSocial members and Club Kawasaki members find out on a 1.8-mile runway by going as fast as they want. Legally!

It’s a fabulously sunny day at Elvington Airfield, just outside York, where Bennetts BikeSocial has organised the Kawasaki Supercharged Showdown – a rare chance for owners of the legendary H2 series to come along and set their own personal top speed records on the 1.8-mile runway. Over 50 H2-ers have signed up for the day, riding a variety of standard and modified sports touring H2 SXs, sportsbike H2s, and hyper-naked Z H2s. Never before have so many supercharged bikes been in the same place at the same time – that’s about 9900bhp’s worth.

Not only that, but Kawasaki UK have rocked up with three supercharged demo bikes – two H2 SXs and a Z H2 – with a standing invitation for anyone who fancies a go to take one up the runway. There are plenty of takers. And in the queue are AJN Steelstock Kawasaki British Superbike riders, Christian Iddon and Max Cook, here for a day off from riding their race-prepped ZX-10RRs – and they’ve got their eyes on the exclusive track-only H2R Kawasaki have brought along. With a claimed 300+bhp and no top speed limit, the H2R isn’t road legal and can’t be ridden at many UK tracks because it’s too loud – so Elvington is one of the few venues in the UK capable of hosting the bike.

And Kawasaki stunt rider extraordinaire Jonny Davies is also here for a lunchtime stunt display; he’s brought along his pair of ZX-6R stunt bikes, and also the H2 SX he used to set the Guinness World Record for skiing behind a bike, at 159.52mph.

It promises to be a hell of a day – and, seeing as entry is free to spectators, the only question now is: why the hell aren’t you here?

What did the riders say?

Alan McCaffrey, H2, 194.79mph

Alan rode 250 miles from Kildare in Ireland, via the Dublin to Holyhead ferry, to take his tuned H2 down the runway at 194.79mph – the day’s top speed for a road legal bike.

“Can I swear? F**k! That was insane,” he says. “I’ve had this bike for three years and it’s like, this is obviously what it’s built for, to go as fast as possible, but you can’t do that on the road, so this is the time and the place. The further I went, the more power, it just never stopped, kept going all the way. The sense of speed is unbelievable. It’s unlike anything I’ve ever experienced, and I’ve gone fast on racetracks and I’ve gone fast on road, but this is just, hold to the stop, hold on for dear life, and yeah, it’s absolutely mega. I can’t believe we’re here, I can’t believe we’re being let do this. This is brilliant.

“The first run I did 171mph but run two I did 194.8mph. The bike is Stage One tuned by Mototuning in Dublin (mototuning.ie), who’ve done a number of my bikes; they’re fantastic. It’s got a Sprint race air filter, a custom ECU flash, per cylinder mapping, and then Gary works on the throttle mapping as well. It makes 248bhp at the wheel.

“I had to fit a new tyre before I came over, and I’m keeping an eye on it just in case for the spin home. But if I go no faster today, I’m happy; I never thought I’d hit that kind of speed so I’m delighted.”

Who was the fastest?

Christian Iddon, H2R, 200.019mph

Christian rides for AJN Steelstock in Bennett’s British Superbike on Ninja ZX-10RRs, but this is the first time he’s ever ridden a supercharged bike. Small, tucked in, flat on the tank, he sets the day’s fastest time of 200.019mph, on Kawasaki’s demo H2R.

“It’s definitely a fun experience,” he says. “I didn’t give it the berries off the line because I knew we’ve got a long run to get up to speed – and yeah, it’s different from our ZX-10RRs race bikes because they set off incredibly fast because they’re geared to do that. We don’t datalog our race bikes for top speed – truth be told they would run out of puff in terms of gearing because we have to gear them for short circuits and we don’t really have straights long enough to get anywhere near. Probably about 180 is about the fastest we ever get on a UK circuit.

“So my race bike won’t do anywhere near the top speed the H2R will do. What was impressive was how it kept making power – I clicked fifth and wasn’t actually sure what gear I was in. The thing still wants to wheelie; it’s an eye-opener and the fact it keeps making power, I guess that’s the nature of the supercharger. Normally power tails off but on the H2R it just seems to sort of keep adding and adding. 200 miles an hour is probably the fastest I’ve ever been.”

Charles Dubier, H2, 182.646mph

“It’s surreal. It’s wow. When you’re on such a special machine, on such a special event, you feel lucky and you feel appreciated as well. It’s funny because I own a Kawasaki and I have my insurance with Bennetts, and normally you don’t expect much from the products you buy – but getting something back makes a difference. And what an event! I came all the way from London, literally rode four and a half hours this morning and now I’m not tired any more. It’s like, yes! Seriously, it’s amazing.”

Ross Glynn, H2 SX SE, 187.151mph

Ross’s H2 SX SE is far from standard. “It’s got H2 rear suspension, a shorter H2 swingarm, it’s got the Öhlins on it and it’s been de-restricted and de-catted, with uprated front brakes and a lot of weight loss; about 20kg down on stock. It’s also derestricted and de-catted. It’s making 224bhp at the wheel.

“It’s done 187mph, which is fantastic. Mildly terrifying, but fantastic. Yeah. Excellent.”

Top Ten Fastest

Why did Kawasaki make the H2 and what does it stand for?

Interview with Ross Burridge, Kawasaki UK Head of Marketing

Bennetts: we’ve had a fantastic day, watching all these H2s blasting up and down the runway. It’s been 10 years already since we first saw the H2, back in 2015 – Kawasaki already built the world’s fastest production bike with the ZZR1400, and then they go and build another world’s fastest production bike with the H2. It’s like, how greedy can you be? Why did Kawasaki make the H2?

Ross Burridge: the short answer to that is because we can. And the longer explanation is basically KHI have a number of different divisions. One is, obviously, motorcycles. Another one designs and builds gas turbines. So, one of the most important things for Kawasaki Japan was to show that they were the only manufacturer able to make a bike like the H2 entirely in-house. Any other manufacturer would have to source a supercharger from somewhere else. But because of the collective strength of Kawasaki Heavy Industries, we used the gas turbine division to build the supercharger, initiate it into the design at an early stage, and therefore build the world’s fastest motorcycle completely in-house. And, of course, it was, I think, the world’s first production supercharged bike as well.

Bennetts: Kawasaki have got a long, rich history of building really fast motorcycles. It’s kind of almost what they’re known for. You can go right back to the original H2, the 750cc inline triple two-stroke. Speaking of which, what does H2 actually mean?

Ross Burridge: the H2 and the H2R are actually a homage to those 70s original H machines. At that time, Kawasaki models were generally began with either an S or an H. And the S stood for Street, and the H stood for Highway.

Bennetts: so Kawasaki top speed icons went from the original H2, through the Z1 a couple of years later, and then the GPZ750 Turbo in 1982, the GPZ900R in 1984, the ZZ-R1100s from 1989, then the ZZR1400 – always moving the game on, always being at the top of the pile. Is being top speed champion important to Kawasaki?

Ross Burridge: it absolutely is. As time has passed Kawasaki have diversified into different areas of the market with really, really strong motorcycles. But it’s true that high speed, high performance thing has always been integral within the Kawasaki brand. Kawasaki’s slogan used to be ‘Hardcore, unconventional and challenging’. It’s a bit of a mouthful for a slogan, but it defines where the H2R is.

Bennetts: so let’s break the H2 series down, for anyone who doesn’t know. In 2015, we had the H2R and the H2, the H2R being the track only, non-road bike.

Ross Burridge: yeah, we started in 2015, which is why we’re here today, to celebrate 10 years of supercharged machines. I can’t believe it’s 10 years ago when we launched the H2R at Qatar MotoGP track – that was actually 11 years ago, the end of 2014. The H2 was the road-going version for people to buy and use on the street, and the H2R was very much track only, over 300 horsepower. An absolute weapon. And it was super-limited edition. It was the halo model. It started off at £40,000 – inflation has worked its way up to £50,000 now. These days we have an order window for six weeks of the year, when you can place your order and the bike is made for you in the factory. The one that’s on the production line is your bike, hand-built just for you at Kawasaki. That’s not bad. The H2 SX was next in 2018; a more comfortable sports tourer that kind-of replaced the ZZR1400.

Bennetts: which is mad when you think about it. Here’s a supercharged engine; let’s give it heated grips and panniers. It’s not the most obvious thing to do. But presumably it was the bigger-selling model.

Ross Burridge: absolutely. A lot more volume than the H2, because it was appealing to a wider customer base. You could go touring to the south of France on it, no problem. Or it’s sporty enough you can take it to a track day and do a track day on it.

Bennetts: and then, okay, we’ve got the supercharged engine. Let’s not bother with the heated grips and the panniers, and let’s just take the fairing off. And we get the Z H2.

Ross Burridge: the Z H2 arrived in 2020, launched at the Las Vegas Speedway. And it’s completed a nice range of machines – brought the total to four and ceated an even wider customer base. And the opportunity to own a supercharged machine for your application.

Bennetts: when Kawasaki first teased the H2 in 2014 there was a lot of speculation about what the engine was because one of the principles of supercharging is you can take a smaller engine and make it perform like a bigger engine, or you can take a bigger engine and make it more efficient. And of course, Kawasaki, in fact, took a fairly large engine and just made it go really fast. So it’s a significant investment for the factory to build this range of bikes – there must be more spinoffs. Is there anything supercharged on the horizon? Is there more life in the supercharged story yet?

Ross Burridge: I think there is more life in the supercharged story. Of course we can’t go into future models, but what we can say is that, after recently acquiring the Bimota brand, we’re now 100% owners of Bimota and we’ve just started distributing them via Kawasaki UK in the UK – and announced a set of dealers for the UK. Next month, we’re launching the Bimota Tesi H2 Terra, which is an adventure-style bike with hub-centre steering and a supercharged H2 SX 200bhp engine. So, again, that’s a way that we’re branching out with a supercharger. What else may come in the future remains to be seen, but we’re excited to explore the Bimota brand.

Bennetts: do you think spin-off technology from the supercharging experience will help Kawasaki in the future?

Ross Burridge: engineers in Japan have created a range of in-house supercharged bikes which gives them a platform to work on future technology in other areas. We’ve got the hydrogen bike in development which, as we’ve seen, has a very H2 look to it. So I think the original supercharged technology offers a platform for these engineers to expand on development of different, possibly alternative fuels for the future.

What does it feel like to ski behind a motorcycle?

Interview with Jonny Davies, UK Stunt Champion and Guinness World Record holder

Bennetts: stunt rider extraordinaire, Jonny Davies, you hold the Guinness World Record for skiing behind your Kawasaki H2 SX at 159.52mph, set here at Elvington?

Jonny Davies: yeah, 0.488mph off 160mph.

Bennetts: why didn’t you didn’t go back for a second go?

Jonny Davies: well, I would’ve been happy with the original record, that Gary Rothwell set in 1999 at 156.3mph. I’d have been happy with 157. But once you do it, you think, oh, I could easily go a bit faster.

Bennetts: the burning question is how do you discover that you’ve got a talent for jumping off the back of a bike and skidding along on titanium shoes?

Jonny Davies: I didn’t discover it until I tried it on this. I’d never actually practised the stunt before. Bearing in mind to practise it, you need a set of titanium skis. Titanium is a lot of money and the fabrication is a lot of money. You also need a bike stable enough to do it. And I didn’t have any of them. So for the Guinness World Record project, I got some people involved; a titanium supplier, and then Kawasaki came on board and said they’d supply a bike. I’d never even tried the stunt until June 2024. And the record attempt was in August. I’d never even done 10mph off the back. I’d actually done it by accident a few times when things had gone pear-shaped practising other stunts on my stunt bikes. But I’d never actually jumped off the back at speed until June.

Bennetts: The first time you did it, did you have someone else riding the bike and they pulled away from standstill?

Jonny Davies: Yes, my dad. To be fair, it was quite a funny Saturday afternoon. So we had my dad riding the bike and me on the back on a closed road, just to see how I felt, and my sister was driving a car with my mum hanging out the window filming just to get some footage to promote it. And I remember saying to the family, like, how many other families are doing this on a Saturday afternoon? Not many. But yeah, that’s how I basically broke it down. Dad riding it, me jumping off and then jumping back on. And it was the jumping off and on was the big thing, really. I was more worried about that.

I got the bike and worked out ergonomically how it’s set out – pegs there, grab rail there. And I was like, how am I going to jump off? I couldn’t actually work out how to. So there’s a bit of technique involved, but basically it’s put your hand through the legs and eventually it feels a bit more natural. Obviously, the first time doing it was a pretty big thing – doing it properly here, because Trevor, the organiser at Straightliners, had to see me do it safely in order to let me go for the record. It was a big day – I jumped off and you can see on the GoPro footage, the fear in my face. And I think I throttled on to about 159 and then I thought, oh no, I’ve got to get back on.

But I’d practised on the stand statically many, many times. The motion was tattooed into my brain. But the thing I didn’t take into account is that the moving floor helps your feet. So I jumped really high because I’d rather over-jump than under-jump. And there’s a photo of me somewhere with my feet higher than my head because the floor dug into the front of the skis and sent me up.

Bennetts: for the record to stand, presumably you have to get back on.

Jonny Davies: yes, you can’t just bail out. The terms of the record are no-one can be riding the bike, you have to climb off the bike by yourself and finish the bike back on the seat.

Bennetts: Arto Nyqvist, the Finnish rider, was the first guy to do it on a Z1300 in the late 1970s, with a pair of wooden clogs.

Jonny Davies: and he had a flat seat – he didn’t have to jump off and back on with a stepped pillion seat and grab rails!

Bennetts: what is it about the H2 SX that makes it good for what you want to do?

Jonny Davies: so obviously the supercharges engine is very powerful. When I met with Kawasaki UK, they offered us a H2 or H2R – they have even more power. But you can only use so much power hanging off the back of a bike, as you probably imagine – so we went for stability. And the SX is a better bike to get on and off. The H2 and H2R don’t really have much of a subframe; they’re shorter. They’re made more for cornering and agility, where the SX’s stability is insane. As soon as I rode it, I looked down the speedo doing 160 or something on a runway, and it didn’t feel like much more than 100. I knew that was the bike. I did 180mph and then let go of the bars to just check the stability, and it just was absolutely rock solid. So then I knew I was fully confident jumping off the bike.

Bennetts: what are the modifications?

Jonny Davies: Kawasaki UK did a throttle modification for me before I collected it, locating a thumb operated throttle lever on the pillion seat, with a wire cable running to the twistgrip. It was a bit of a tricky thing with it having an electronic throttle to adapt with a cable, but the guys there have done a fantastic job. But apart from R&G crash protection, it’s standard.

At the end of the day

As the sun sets on Elvington, and the sound of the last supercharged H2 fades into early evening air and riders begin to depart for their – hopefully somewhat more sedate – rides home, it’s been another splendid day of speed and adrenaline, courtesy of Kawasaki and Straightliners. We’ve seen the double ton broken, a man ski behind a bike, some crazy stunts, eaten lots of burgers, talked lots of banter, and seen speeds people who weren’t there merely dream of.

Same time next year?

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Do you own a supercharged Kawasaki? Tell us what it’s like, or ask us questions about it at bikeclub.bennetts.co.uk.