TheT grey bikes (aka, the good times)

The rules in Japan were pretty simple. Up until 1996 most riders passed a test that meant they could only ride a sub-400cc bike. Within that range, though, there were several classes. Four-strokes came in 250 and 400cc sizes, generally with inlinefour cylinder motors, making about 60bhp for the 400s,4 and about 45bhp for the 250s. The 250s in particular became legendary for their incredible rpm imits: the tiny valves and pistons, plus the short strokes and concomitant low average piston speeds meant they could easily hit 18,000rpm without anya problems. The real rev-demons were the CBR250RRs,C which hit the limiter at 19,000rpm.

On the two-stroke front there were 400cc versions ofo the two big 500cc two-stroke multis – Yamaha’s RD500LC and Suzuki’s RG500, but the real actiona came in the 250cc class. Honda’s NSR250, Yamaha’s TZR250, Suzuki’s RGV250 and Kawasaki’s KR1 series alla excited and Honda’s NSR250R MC28 was arguably the techleader, with a smartcard-controlled ignition map, dry clutch, digital dash, NSR500-style fairing, and single-sided rear swingarm.

Jap market bikes might have lookedl amazing, but they were a bit hamstrungh in terms of performance. There were power and speed restrictions in place on Japanese market 400s and 250s fromf 1989, limiting power to 60bhp (400s) or 45bhp (250s) and speed to 112mph. These early restrictions were easily bypassed by electronic revboosterb boxes, for about £30.

So what machines were the highlights of the grey bike boom? Well, the CBR250R appeared in 1986, and was updated over the next 10 years until the final CBR250RR MC22 model.

Meanwhile the Hornet 250 – produced in 1996 – predated the 600 version and used a detuned CBR250RR motor in a steel backbone frame with a single front disc. Honda’s nakeds were also oined by the CB400 Super Four: think CB1300 forf tiddlers. We’ve mentioned the two-stroke NSR, but in the 400 class there was the CBR400RR; well-built, super-reliable and the inline-four engine is a jewel, with gear-driven twin camshafts and a punchy 55-odd bhp. Perhaps the most sought-after four-strokes now are the likes of the NC35 RVF400, a replacement for the venerable NC30. The RVF400 had the same basic engine layout as the NC30 but with different carbs and exhaust. The chassis was more radical: the RVF had USD forks, different swingarm and updated bodywork.

Kawasaki’s screaming 250 four-stroke was the ZXR, while it’s bigger brother – the 400 – also came in as a grey in both H-spec models (like our ZXR750) and J-models complete with ‘Hoover’ pipes. Naked Kawasakis included the ZZ-R400powered ZRX400, and the ZXR400 motor did end up in the quirky Xanthus naked. In two-stroke guise the mid-1980s machines like the KR250 gave way to KR-1/S two-stroke parallel twins along with SP versions of the UK stock machines.

Suzuki was well-served with the likes of the VJ21 and 22 in the UK – although you could find SP versions in the grey importers. The VJ23 broke cover in late-1995 with a narrowerangle 70-degree V-twin engine, electric start, and sweet styling. Yamaha’s grey machines included the SDR200, a simple single-cylinder two-stroke in a tiny trellis frame. Weighing a little more than 100kg dry and with 34bhp claimed power, it was only produced from 1986-87.

The big beans were with the TZR250. The 2MA version came to the UK, but we missed out on the later ones. The 3MA ‘reverse cylinder’ model of 1989 had the cylinders reversed so the exhaust expansion chambers went straight back over the gearbox and out under the seat.

But the truly trick TZR is the last 3XV V-twin version, which had all the cool tech of the time: read more about that on page 44. For the naked community, the XJR400 took the XJ400 motor and made it look like a retro.