Find an excellent example and you'll realise why this was one of the key machines that transformed sports bikes. "Life changing,"' as Whit would say. So let's set the context: early '80s sports machines were heavy and wallowy.
The first GSX-R750 (it was sold as a 400 in 1984 in Japan) was incredibly light at 176kg with sophisticated suspension and race-ready brakes. Oh yes, and it came with drop-dead gorgeous racer styling, to all intents looking like a factory endurance racer, and finished in factory colours to boot. In 1985 there was nothing sexier.
And if it looked good in the showroom, it positively set the racetracks alight. Some of us will remember Kevin Schwantz's Transatlantic racer,used to batter the hell out of Wayne Rainey's VFR750. The more cultured among us remember Mick Grant's island swansong, winning the 1985 750 Production TT on this, the first of the GSX-Rs.
Despite the successes, though, the GSX-Rs had their problems, and significant ones for the racers. Essentially they were too light, underspec'd on wheel spindles, swingarm pivots, quite possibly even on frame thickness (alloy box sections set in traditional duplex format). The following year's G model rectified these issues and added a longer swingarm to boot, which went a long way to calming the GSX-R's lively ride. Compared to today's bikes it's still awesomely light (although today's GSX-R750 weighs a claimed 163kg), it's also spacious and torquey, even if it lacks the rigidity, razor-sharp handling and searing top end power.
The problem is most are nasty auld knackers or dodgy imports. Good ones are out there, but many will have been affected by the passage of time and miles. Expect some scratches and paint fade on the bodywork (and there's lots of it), and budget for new bearings, bushes, suspension seals and fork oil unless there are receipts to prove the work has been recently done.
Avoid all 'street fighters', anything tuned or heavily modified. Look for cherished machines either standard or with sensible chassis upgrades. And be quick, or Mr Whitham will have it away: "They're fookin' great, if I could find a really good one I'd have it, sharpish."
Key ID: flat-sided rear panels, hence nickname 'slab-sider'
Don't fear: higher miles - the engines are very strong
Also consider: 1986 Suzuki GSX-R1100, 1988 Yamaha FZR1000
1985 Suzuki GSX-R750 Specifications
Engine 747cc, 16-valve air/oil cooled in-line four DOHC
Top speed 160mph
Power 106bhp @ 10,500rpm
Torque 47 ft/lbs @ 8,000rpm
Compression ratio 9.8:1
Bore x stroke 70 x 48.7mm
Front brakes Dual disc
Rear brake Single disc
Dry weight 176kg
Seat height 755mm
Fuel capacity 19 litres