Track testing Crescent’s Suzuki GSX-R600 and R750

Published: 01 August 2001

WHO did you want to be when you were a kid? My idol was Barry Sheene and the memories of the one and only time I ever saw him race – at Oulton Park when I was 10 years old – are still carved in my brain.

I remember his Suzuki race bike howling and screaming as he out-cut and out-thrust the best of the rest around the scary, wheelie-provoking Cheshire spaghetti circuit. I’ve never seen him in action or been to that track since. But I’m back again today – this time as a rider and not a spectator – and I’m armed with 45 grand’s worth of pukka Suzuki race tackle – except, bizarrely, this stuff is almost road-legal, too. Almost.

Let me explain. I might not get to play at being Bazza here today, but I can pretend to be Supersport 600 young gun Karl Harris, or British Superbike star John Crawford. I’ve got an exact replica of Harris’s bike – and that includes the engine internals – plus a close copy of the bike Crawford hammers.

And the best bit? Suzuki has tied up with the lads’ race team – Crescent Suzuki – to produce the bikes in limited numbers, so now anyone can buy a slice of thoroughbred action if they have the cash. You’ll need to be well-heeled. The GSX-R600 is £15,000, the GSX-R750 a wallet-worrying £30,000. But they’re worth every penny and more. And if the price just isn’t right, you can order bikes built to a slightly lower spec, or just arm yourself with a few or all of the kit parts if you have a donor machine. Both bikes are classed as road-legal by Crescent, though, strictly speaking, they’re not.

So, here’s the disclaimer – race numbers, full-on track exhaust systems and obscured main beams are either illegal or won’t get you a full MoT and could, therefore, invalidate your insurance, too. An absent chain guard, a hidden brake and rear light display and missing indicators (technically illegal when the original switchgear is still in place), won’t score bonus points during a roadside check, either. And, in the case of the 750, the lack of a horn is a big no-no.

You can get round all of these problems with a minimum of fuss if you want to ride the bikes on the road by choosing a different (not necessarily lower) specification. Crescent will help you. Both bikes have been built to show the limits of what can be done to production tackle and, if you’ve ever decided to go racing then found yourself forking out thousands of pounds to get a road bike into track shape, you’ll immediately agree they’re good value.

The 600, in particular, is well worth the dough. Crescent claims it makes a mind-blowing 120bhp at the rear wheel – a figure unreachable in 600s until a year or so ago – and weighs exactly 167kg (367lb) with oil, water and all other fluids except petrol.

The wet weight is the FIM’s legal minimum and probably equates to around 157kg (345lb) dry, giving the 600 a power-to-weight ratio of 0.76bhp per litre – exactly the same as Honda’s FireBlade. And the outright power isn’t even its best attribute. That accolade goes to the handling.

The 750 has to try harder to justify its price tag, though when you see the list of parts, you can understand the high cost. Crescent doesn’t expect to ever sell a bike built to this magnificent spec and reckons most riders will opt for a package that saves them a grand, or 10. But if you can afford it and you’re nuts about performance, this is the way to go.

The firm hasn’t released the power and weight figures yet – the bikes were only finished on the day MCN collected them, but we estimate around 150bhp and 159kg (350lb). That means 0.94bhp per litre, which beats just about anything and, again, the handling is even better than the motor. Whatever the technicalities of their legality on the road, this pair is better suited to track use. So we tested them in both domains.

The trip to Oulton was proving interesting. Features editor Marc Potter was driving the MCN van, enthusing about anything two-wheeled as usual, and wondering how either of the test bikes could even begin to compare to Freddie Spencer’s 500 triple, which he rode a few weeks ago.

I was hanging out of the window, doing my best not to be sick, and attempting to chat about the 180bhp Honda Racing FireBlade I rode last week and how bikes properly set up for track use are king. Forty miles after leaving the office, we made the first of a few unscheduled stops.

I now realise the smell of race fuel – that’s what the bikes were filled with – makes me ill. Violently. I hung out of the window for the next two hours on our journey to the hotel due to put us up for the night before testing. I’d only been out of hospital a few days after haemorrhaging two pints of blood during a " routine " tooth extraction and didn’t need the added complication of a misbehaving stomach.

But it’s preferable to having to share a room for another night with Potter. Marc, you snore. I awoke starving and knackered, guts still entangled, then had the first of several mystery nosebleeds. But I didn’t care. I was riding some of the world’s best kit and nothing was going to get in the way. Or so I thought. Ever tried barrelling around an unfamiliar race track with a pool of blood working its way up the inside of your visor? Neither had I. Cauterise nose – something else to add to the list.

Oulton was hosting an MCN track day (more to come, for details call: 01953-888789). We unloaded the bikes, listened to the safety briefing, then signed in. The friendly pit lane chats went something like this.

" Cor, that’s a nice bike. Is it a tricked-up thousand? "

" No, it’s a 600. "

" Well, that one must be a thou, then. "

" No, that’s a 750. "

" Eh? "

Finally, it was time to go out. The " experienced " group had about 25 riders in it, of which around a dozen had been to Oulton Park over 10 times each before. One guy had been there 24 times. The rest, it seemed, had somewhere between a few and half-a-dozen visits under their leathers. Then there was Potter and Farr. Total Oulton track time: 0hrs 0min.

I’d been told the circuit was like Cadwell Park on acid. Scratch that. Try Cadwell on every mind-bending, mind-blowing concoction ever made. At low speed – during the sighting laps and the initial track session – it made no sense at all. Everything seemed wide open, but tight, too. The corners looked unfriendly and crests initially explored at 70mph seemed to yell: " Double your speed, then we’ll make you leap. "

The bikes trickled merrily along in the sighting lap procession, the 600 burbling and bogging slightly if the revs dropped below 7000rpm. It took half-a-day to learn the track to the point where only a handful of regular Oulton addicts on tuned litre bikes were getting by.

The learning curve to crack the track is massive, but it’s greatly helped when you’re on two of the sweetest handlers ever built. There’s nothing like the reassuring sight of sticky rubber at an unfamiliar place. In the case of the GSX-R specials, it comes in the form of Dunlop D207 GP tyres – the choice of many a 600 racer at every level from club up.

They warm-up more quickly than many rivals and, because of a pronounced, angular profile, help any bike they’re on turn quickly. Though the GSX-R600 is identical to Harris’s bike, it isn’t set-up the same. The rear isn’t jacked up quite so high and the steering geometry is slightly more relaxed. Crescent will set the bike up any way you want, but gave this bike a softer edge in case we wanted to ride it on the road.

Try blasting up your favourite roads on a bike with proper short-circuit racing geometry and you’ll find the chassis feels ridiculously unnerved. The Crescent 600 feels more like a bike set up for a tough road circuit. It could almost be off in search of a trophy at the Isle of Man. Firming it up even more takes only seconds thanks to an Ohlins Supersport-spec rear shock and different fork springs.

It has next to no turning lock, so getting to the holding area from our van had been a job in itself. The full Yoshimura exhaust system barks distinctively, changing from a subdued growl at low revs to a rabid, angry snarl as the needle spins around the dial. A Yoshimura display accompanies the stock clocks and tells the rider the bike’s temperature and the state of the electrical system. Oh, and it has a lap timer operated by a yoke-mounted button, too. Now, that’s handy.

The brakes – stock four-piston Tokico calipers running on angular Wave discs – have taken some getting used to. As Crescent boss Paul Denning says, they’re either fully on or fully off. There’s so little in between. Harris loves them and they’re growing on myself and Potter, too.

They feel strange at first. The usual progressive feel of a road bike’s stoppers is missing. The difference is largely down to the discs’ unusual shape, which results in more even pad wear and means there’s less likelihood of glazing. It has a self-cleaning action too.

Race-compound pads and Goodridge hose complete the picture, along with a trick span adjuster which operates from the left bar and is attached to the front lever by means of a cable. Supersport rules state the original lever must be used. This is – it just has an addition to help riders adjust the span on the move at race speed.

The bike’s already flying as we round the first, long left-hander. The corner doubles back on itself, but is wide enough to keep the power on hard and get even more pumping out on the exit. It’s a top place to make up time, if you have the nerve and the 600’s needle is living between 13,500 and 14,000rpm.

There’s an RSV Mille a couple of yards ahead and the owner’s late getting on the gas. The GSX-R just shows it a wheel before the litre twin is opened up and its superior stomp starts to pull out a lead.

But the 600 has the inside line for the next bend, a much faster, longer left, and the Mille, with its race can and chip, isn’t pulling that much out. Its rider leaves his braking as late as he possibly can to turn in, but that point is a full 50 yards earlier than the GSX-R’s. The ferocious brakes, light weight, brilliant suspension and sticky tyres allow a few liberties here and there.

Little more than a quick, hard dab is needed to slow the bike enough for the corner, which is followed by a very off-cambered, banked, right-hand loose hairpin. By the time the 600 has exited this, the RSV has fallen back, nowhere to be seen.

A pukka Yamaha TZ race bike is just ahead and it streaks through the next main bend – a tight left-right chicane. The 600 is on its tail and turns even more tightly and quickly than I thought it could. I’m expecting the rear tyre to slide as I gas the bike out hard, following the track to the left. It just grips and slingshots me forward.

The 600 has the legs on the TZ over the crest and down the back straight. The close-ratio box is zipped through in a few seconds as the bikes hurl to the left side of the track for a fast, lean-like-fury-and-hold-on right-hander preceding the infamous Clay Hill.

The GSX-R has nosed ahead of the TZ and charges through the corner in a manner that suggests it could have done it 20mph quicker and still got away with it. The trick with riding either of these GSX-Rs is to forget the limitations of a road bike and think of them as pure race tackle instead. They’re so much more capable than they look – and they look up for a crack at anything.

The 600 crests the blind summit Clay Hill, the front wheel briefly popping skywards as the bike runs out to the right side of the track before peeling left to line up for a lovely double-apex right-hander. This is my favourite part of the circuit and a great overtaking opportunity. The bike has been following a trickle of nicely-prepped track day tackle and I must get past.

I drop back a fraction, down-shifting hard, and delay my entry to the corner. Everyone else has peeled in, but I want to end up on a tight line on the exit, to lay serious power down knowing the others will be drifting outwards, away from me.

The bike turns so much tighter than any road 600 ever built and the chassis feels completely planted. Then it’s hard on the gas, over a pronounced lip by the circuit’s low-slung bridge. The front wheel lifts high under power, holding itself in the air as the bike changes gear. It lands with a shimmy and settles down immediately. Crescent has fitted a top-spec, adjustable Ohlins steering damper and it shows.

The 600 has nipped under the other bikes and is holding the inside line for the next right. This is the bend I don’t like – I’ve seen a few people fall off here today and it’s easy to run out of track on the exit if you peel in too early.

I keep the throttle pinned as long as I can to make sure nothing sneaks up outside me. Then I pull wide before hitting the brakes hard, slamming down through the box and peeling in on a perfect line.

The corner marks the beginning of a rollercoaster section where the bikes and your stomach drop maybe 10ft into a dip before emerging the other side, cranked hard over left, for a blast past pit lane and back to a confusing but beautiful right-hander that takes you back to the first left you encounter after leaving the pits.

The 750 is a completely different animal. Where the 600 feels race-focused, the 750 feels race-bred. It’s set up slightly differently and has a more committed riding position. Thankfully, it also has a better turning circle.

Amazingly, it’s much quieter than the 600 and sounds almost sedate enough to use on the road – until you rev it hard. The brakes are less fierce than the 600’s. The fronts are beautifully-crafted six-piston AP calipers biting on fully-floating discs through race pads. There’s a double reservoir AP master cylinder with a different piston size to the stock unit and an AP lever with a span adjuster that is easy to use on the move. The upshot is massive stopping power, but more feel than the 600’s arrangement.

There’s no lap timer on this bike, just a digital temperature gauge, but it’s at odds with the bike’s stock one which is still fitted. The Yoshi is reading 10° lower than Suzuki’s and sticking to it. Who cares, as long as the huge race radiator, which is so big there’s no room for a fan, doesn’t overheat?

This bike turns seriously quickly. Gyroscopic forces have been reduced by fitting the lighter calipers and discs. And there’s a set of magnesium Marchesini wheels, too. The five-spokers save a couple of kilos and look the business.

The wheels are bolted to inverted factory Showa forks, which are held in place by huge magnesium yokes bearing the legend JC#1 – Crawford’s originals, by any chance? As with the 600, the fairing is made of carbon-fibre which is stronger than standard, but lighter, too.

The 600 has a stock fuel tank, but the 750’s is aluminium and a work of art. The screw tensioning the filler cap’s rubber seal needs adjusting, though, as the tank sloshes race fuel into the expandable crotch seam of my leathers. My balls are tingling, but for the wrong reasons now (tip – wash race fuel off your nuts as soon as possible. It burns deep enough to remove a layer of skin).

Though both bikes are filled with race fuel, they’ll use unleaded in its absence. But the engines are so highly tuned it has to be of the Super variety. Otherwise, expect detonation and a lunched motor. The only problem, if you use either bike on the road, is finding Super. Not every garage stocks it. In fact, we found three out of four non-motorway garages in Northants no longer had it. Yikes.

Where the 600 felt strong, the 750 felt like an animal. It turned and stopped as quickly as its lighter, tighter little brother, but, with about 30bhp more on tap, yomped away whenever the throttle was opened. It marked the start of a strained relationship between us and race control. We both got rollocked for pulling wheelies – which the marshals at Oulton are seriously against.

Except neither of us were hoiking them voluntarily – the power of the 750 simply made the front wheel lift in places on the track the marshals argued it shouldn’t have been able to. We could say, tough, it does, that’s all there is to it, but they had a different view – one more wheelie and we were getting thrown out.

That meant having to stand up on the rearsets and lean over the front of the bike in a few places on the track. I know which method I think is safer…

For all its race tuning, the 750 remains surprisingly tractable, glitch-free and torquey. It has enough pulling power to out-drag litre bikes before the engine’s fully " on cam " . There are no surprises – its manners are like a road bikes – except this one’s got serious attitude and 20 to 30 per cent more of everything, everywhere.

Both are easy to ride, look a million quid and could be raced as they come (if you remove a few road bits). They’re surprisingly competent on the road too – though we don’t recommend it. Aside from the technical illegalities, they’re simply too quick. It’s true a bike only goes as fast as you let it, but try riding one of these and not opening it up. It would test the self-restraint of a monk.

On full chat, the 600 can, literally, be heard a mile away. The savage bark cuts an eerie echo through the silence, becoming more menacing as the bike approaches. The chassis feels set-up nicely for fast road work and, therefore, only comes to life at illegal speeds. Riding at 70mph is no fun at all.

You’re either in third, fourth, fifth or top gear way out of the useful pulling rev range, or you’re on a knife edge in second with the bike poised to surge crisply forward at the merest millimeter of throttle input. The race numbers, noise and sheer unique appearance of the bike guarantee it won’t be long before you’re pulled over.

The 750 is a different animal. The bigger engine is more tractable. It will let the bike run at legal speeds in a higher gear, with enough immediate response in the top three ratios to get you out of trouble if an unplanned hazard emerges.

It’s also a lot quieter, despite its twin-exit end can, which looks like it should put the bark of the 600 to shame. Changing down from top to second gear and nailing the throttle is a hoot. The world goes from sedate to hyperdrive as the front wheel belts into the air and vehicles travelling at roughly the same speed as you appear to halt, then slam into reverse.

Like the 600, the chassis doesn’t really get working until you’re well into triple figures – though the superb range of suspension adjustment at both ends means it’s quick and easy to transform the handling for more sedate speeds.

So, where do these bikes fit in? Are they really intended for hard track use? Would they be better off actually racing than completing endless track days? Or can they really be used on the road?

As they stand, they’re track day machines – they still need work for racing or road use. But they only exist to show what Crescent can do. Lose the race numbers, fit tiny indicators, removable mirrors, chain guards and, in the case of the 750, a horn and either bike is almost ready for the road. Tweaking the suspension would make them eminently more rideable. And the 600 would have to run with a quieter end can, no question.

The obscured rear lights would remain open to debate, but chances are you could use the bikes on the road without getting pulled. Then, when you arrive at the track, remove the mirrors, fit the race can you’ve bungeed to the back of the bike, reset the suspension to track settings (two minutes front and rear) and off you go.

For the racers among you, ditch the pricey fairing, get a £100 GRP item and prepare for the same thrills as Harris or Crawford. They might not be totally practical, but these GSX-Rs really can be all things to all people.