The Ultimate R
Riding £30,000-worth of Suzuki Slabbie concentrates the mind beautifully: Bertie Simmonds and James Whitham on the agony and the ecstasy of the GSX-R750F.
It could be argued that the Suzuki GSX-R750F was the most focused motorcycle yet developed and the marketing brochure confirmed this. The cover showed the new GSX-R750F on Paul Ricard’s hallowed circuit with Suzuki’s GS1000R XR41 endurance racer sat just behind. The marketing blurb said: “Born on the circuit and returned to the circuit,” adding, “This is a sportsbike derived from our works race bikes.” And they weren’t wrong, as the 1985 GSX-R750F was indeed developed from the works endurance racers which had been successful in the early 1980s. Etsuo Yokouchi was put in charge of development of the GSX-R, a road machine which was to ape the previous XR69 and XR41 race machines, but with the 750cc capacity that was to be dictated by 1984’s 750cc endurance racing capacity cap. Yokouchi-san had been Suzuki’s race team manager in Europe from 1983 and spent his time asking road riders what sort of machine they would like to see built. Many wanted a no-frills, race-replica machine and so the seeds were sown for the GSX-R. First to come was the GSX-R400 developed for a 1984 model year launch. The name came from the-then current four-stroke models’ prefix of ‘GSX’ which were then given an ‘R’ for ‘Racing’. The GSX-R400 was also derived from the XR41, as well as the Yoshimura TT-F3 racers from Japan. With the road 400R being almost 19% lighter than the opposition, the design team for the 750 aimed for the same target, which meant a weight of 176kg.
Work on the 750cc machine began in the autumn of 1983 and production was agreed in January 1984. Initial engine work was undertaken using an existing GS/GSX750 motor, where the various parts were destruction tested to see what parts were ‘over-engineered’ and where weight-saving could be made. The 750cc GSX-R was going to need to be light, powerful and reliable. They managed all three, as one slave GSX-R750 engine would be destruction tested at 12,500rpm (2000rpm over peak power) for 30 hours: it survived. Suzuki’s in-house magazine Suzuki Tech News at the time explained that the weight saving worked. Over the previous GS/GSX750, the new GSX-R750F parts were lighter as follows: pistons 11% lighter, con rods 25%, crankshaft 19%, cylinder head cover 39%, cylinder head 22% and cylinder 17%. The large bore size of 70mm and shorter-stroke of 48.7mm of 749cc compared to the GS/ GSX’S 67mm and 53mm (747cc). The combustion chambers of the 750 also used a new version of the TSCC or ‘Twin Swirl Combustion Chamber’ for improved fuel-burn efficiency. The new GSX-RS, both 400 and 750 would share the look of the XR racers, the twin-lamp endurance stare and the double cradle frame. Under the full fairings there were bigger differences: the 400 would have a liquid-cooled 398cc motor and the 750 would utilise air and oil-cooling known as ‘SACS’ (or Suzuki Advanced Cooling System) including under-piston oil-cooling, similar to that found in Rolls-royce Merlin aero engines from the Second World War. Power output for the 750 was tagged at 100bhp and the lack of liquid-cooling was put down to weight: the development team simply couldn’t allow the weight of a radiator, hoses and the associated paraphernalia to be added to the basic engine architecture. Chassis-wise the double cradle frame would be made of aluminium – Suzuki made perhaps the first production frame of this material with the RG250 in 1983 and the GSX750. The GSX-R’S frame would be made of just 26 components (the GSX was made of 96 parts). At just 8.1 kilos, the frame weighed about half that of a conventional steel frame. Suspension would be 41mm forks featuring Suzuki’s New Electronically Activated Suspension (NEAS) and the forks themselves were ‘PDF’ or Positive Damping Fork, which was a crude anti-dive system. The GSX-R series seemed to launch a thousand acronyms of this sort! At the rear the ‘Full Floater’ single shock system utilised 35% fewer parts than Suzuki’s previous 750 machine, wheels were 18-inchers (again aping the endurance race bikes) while another acronym ‘DOP’ or Dual Opposed Piston was the name given to the four-piston calipers that grasped the 300mm race-replica drilled steel brake discs. From the go-ahead in January 1984 the bike was finally testing towards the end of May at the Ryuyo circuit in Japan, Suzuki’s own track, by October the bike was at the Cologne Show and the first production bike came off the Hamamatsu line on January 25, 1985. The reaction to this amazing machine was instantaneous. The previous year had seen the GPZ900R from Kawasaki take the title of the best sportsbike of the 1980s so far, but the GSX-R750F took that away from it after just a year at the top. Even machines launched in 1985 such as the Yamaha FZ750 and Suzuki’s own RG500 two-stroke couldn’t compete. Road testers gibbered of quick steering (a 1463mm wheelbase and 26º steering angle made up for the 18 as opposed to 16in wheels) and a manic power delivery over 6000-7000rpm. Some tests warned that the GSX-R commanded respect: here was a machine that was truly ‘born on the circuit’ and it was no surprise that in production racing it would return to it, too. Meanwhile on the roads it was nothing short of breath-taking.
Looking at figures from the day the GSX-R750 probably put out 90-95 real-world bhp compared to the FZ750’S 95-100bhp. But while the Yam had more mid-range the Suzuki was carrying 25 kilos less than the FZ from the get-go and a whopping 45.4 kilos less than Honda’s VF750F. The GSX-R had shown the direction that sports bikes would go in for decades to come…
The ride
Given my previous comment on production racing, it seems fitting that I pick up Suzuki GB’S immaculate GSX-R750F at Silverstone race circuit. The bike is in the care of Daryll Young from IDP Moto as Nathan Colombi the man behind the Suzuki GB rebuild spannered his clavicle on a track the day before! Daryll digs out the keys, switches the ignition on and pulls out the carb-mounted choke plunger then hits the starter. I’ve ridden a few of these ‘restored’ 750 Slabbies and while this stunning machine is clearly better than any other I’ve ridden, even this one takes a while to get onto all four cylinders. With the bike fully warmed up it’s time to swing a leg over the thing and… OUCH. I can’t fit on it. The pegs are so far up and to the rear that my legs have to really contort to get onto them at all. It takes me all the perimeter road around Silverstone before I can get my feet on the pegs comfortably. What is wrong? As the miles go by, the pain eases a little and hitting the A43 means it’s time to open up the GSX-R… Wow. I’m still impressed. Sure, it’s not as tractable as some power units, but this – heavily rebuilt and ‘as-new’ motor – is the best Slabby engine I’ve ever ridden. The tacho only starts at 3000rpm, so that should give you a hint of how it performs. Nothing much happens but noise until around 6500rpm but then the thing just takes off… like, really takes off. The kick from 7000rpm to the 11,000rpm redline is seriously manic and addictive – even in this sanitised ipod age. It’s such good fun. I’m conscious that this bike is worth around £30,000, so I’m using the slightly heavy clutch on the up-changes and the gearbox is as sweet a nut. Now, brake-wise I felt that the work Nathan had done on these DOP brake calipers has been time well spent: you needed to haul on the lever, but the anchors matched the acceleration no problem at all. The faster I went on the GSX-R, the more natural the seating position felt: those feet of mine still felt like they were tucked up behind my bum cheeks, but the stretch to the bars wasn’t too bad at all. You always feel like you’re planted ‘in’ the GSX-R, too, rather than ‘on’ it. And – as narrow as the bike was without a water-jacket back in the 1980s – there is a certain width to the bike and the motor itself pumps out a fair amount of heat. The feel and smells of this motorcycle are so 1980s. One thing that is curious is the handling. The bike seems just a tad ponderous. A good hour on board and I arrive at the photo location to meet industry legend Mark Forsyth and his lovely Honda SP-1 (more in a future issue). He thinks it’s the tyre pressure in the rear, so we check and with 31psi (probably low from the track outing with James) we up it a few psi to see if it makes much difference. It does, a bit, as I scythe nervously (well, it is a £30k Slabbie) through the bends. I’m getting to like the
bike, but I’m still not sold on the handling really. MF has a pop on it and agrees. I know I’m a big bloke, but my conclusion is that something isn’t quite right with this 750F’s rear suspension unit. If it’s sitting that low without returning to its normal position not only would this cause the bike to steer considerably slower than normal, but it also means that the ergonomics are going to be that bit more uncomfortable. What is right are the tyres: whatever pressures we ran them at the Conti Road-attacks were absolutely superb and suited the bike down to the ground. I’m not going to dwell too much on the handling issue, as Whit’s feelings of riding the thing much faster than me around Mallory Park some weeks before are what needs to be remembered. Either way riding it is an agonizing joy. I get to keep the thing in my garage for a whole weekend and (when my knees are feeling up to it) I go for a ride. People check you out on the GSX-R: a lot. Even today, you’ll get appreciative glances when people see you on this handsome blue and white machine. After a weekend with the GSX-R it has been both agony and ecstasy. Agony has been the cramped ergonomics and the ponderous handling but the ecstasy has been that willing, revvy motor and kudos of riding a real legend: in fact, riding the best of a breed.
Running and owning
Slabbie prices are on the up. This very example looked tidy, but was a bit of a mess when Nathan pulled it apart and still cost £2500. Initially the aim was to build the best GSX-R750F in the country for around £15,000 all-in. Nathan and Tim Davies et al did just that, but the rumour is that it cost closer to £30,000. Crazy to most CMM readers, I know, as you could pick up a rough one for £2000 and spend a further £2k doing it up and have something very serviceable, but this is (even with a curious handling issue) surely the best 750F in the UK. This bike, then, clearly is there to earn column inches for Suzuki every time a new GSX-R is released and showcase what an array of parts they have on offer at www.suzuki-gb.co.uk/motorcycles/ my-suzuki/vintage-parts. Their ebay shop is very impressive too. You’ll be surprised what is available, but what isn’t are the likes of good, original F-model fairing panels (three bolts on the top cowl) headlights (hen’s teeth), screens, fuel tanks, carb bodies (but almost all of the internal parts are available), mirrors, the drilled (rather than later, slotted) end-can heat shield and right-hand brake discs: you’ll need to de-rivet left-hand ones and re-rivet them. Pretty much everything else is available – for a price, of course. Finally I have to add here that – while it’s lovely that the main people at Suzuki GB have bought into the fact that we need old parts for our bikes, let’s not forget those that have always been helpful: so checkout Robinson’s Foundry and Crooks’ Suzuki!
Conclusion
I’m going to be popping back to ride this GSXR750F at some point. Either when the shock is sorted or when I’ve lost weight! That’s the only question mark on this bike and yet the importance of this machine in the lexicon of motorcycling is huge. Think of the raft of GSX-RS that have been built in various capacities, or the number of famous racers who cut their teeth on GSX-RS, the specials builders who’ve created Streetfighters, or custom street bikes from GSX-RS and their associated parts. A better motorcycle journalist than me, Roland Brown, once wrote the following which was the perfect way to end a book about the GSX-R which I had written. He says: “If modern motorcycles began with the Honda CB750 of 1969 then sports bikes began with the GSX-R750F of 1985, which – looking back through biking history – makes it the second most influential bike of the last century.” Thirty-one years on and I really still can’t argue with that.
Useful contacts:
www.gixxer.com www.gsxr.com www.gixerboyz.co.uk www.suzuki-gb.co.uk/motorcycles/my-suzuki/vintage-parts/ www.crooks-suzuki.com www.robinsonsfoundry.co.uk