Honda goes two stroke
Although known for their fine four-stoke creations, Honda did, for a short period at least, produce one of the finest road going strokers too. Never the fastest, but certainly the nicest to ride, the NS triple displays sure-footed manners not seen before in a road bike, MSL catches up with a fine example to see what all the fuss is about.
The mid 80’s was the time of the race replica and, with Honda having finally admitted that a two-stroke was needed to be successful at GP level, three of the four major manufacturers had large capacity, two-stroke, road machines on offer. The Honda NS400R is a marvel of engineering, literally bristling with whistles and bells at every opportunity, making the bike a testament of the way things were done at the time. Little is allowed to go about its business without some kind of intervention form the designers, the exhausts of the two front cylinders, have valves that open and close to alter the resonant frequency according to the engines revs, while the forks have anti dive valves that progressively stiffen the front end as the brakes are applied. This was the period of the acronym and everything that could have, had a set of letters boldly emblazoned about the machine, names like TRAC and ATAC (Torque Reactive Anti dive Control and Auto controlled Torque Amplifications Chambers respectively) abound, these devices no doubt fitted with the intention of gaining a sales advantage by likening the road machine to its pure bred race brethren. Unlike so many other gimmicks of the time, this technology works well, creating a machine that simply goes about its tasks without fuss or commotion. Handling is sharp, as is the steering, the small diameter, 16-inch front wheel allows the front end to be thrown around freely while the rest of the frame work, wrapped up in a short, 1362mm, wheelbase holds it all in shape nicely. Looking around the ripple reveals the build quality to be head and shoulders above the rest of the oriental pack of the period, lavish paintwork and snug fitting bodywork is typically Honda at its best. The same can be said for the parts under the plastics, every component is built to high standards and if anything over engineered. Inside the engine is a lesson in friction reduction, just like the race machine, the crank spinning in special bearings while maintaining a perfect balance, removing the need for power sapping balance shafts unlike the four-cylinder strokers from Suzuki and Yamaha. The NS prefix to the model name refers to the use of nickel and silicon carbide for the lining on the cylinder walls, common place nowadays in most vehicles but advanced stuff in the mid 80’s for all but the latest factory race machinery.
The result of Honda’s labours is a great bike in its own right, overshadowed by the other two, thanks to the strange choice of capacity, a decision no doubt steered heavily by the limits in place in Japan that saw Yamaha and Suzuki produce 400cc versions of their machines for the domestic market while the rest of the world got the full blown example.
Just like Freddie?
Never the most powerful of the mid 80’s strokers, the Honda triple does have many other attributes that help win the day. The 90-degree crank layout gives a relatively good spread of both power and torque making it the easiest to ride of the bunch, it can potter around all day before rushing off in a cloud of blue haze at a moments notice should the revs be allowed up into the strong power band. Just like the friendly power plant, the chassis is a delight too, many rate the RC30 as the first of the great handling Japanese machines, however, due to the relatively scarcity of the triple stroker, most will have missed the experience found a few years earlier. The lightweight, box-section alloy frame works so well great liberties can be taken during the cornering process, the main reason may well be the relatively low power developed by the 387cc triple, hardly likely to trouble the metalwork which wouldn’t look out of place getting up close and personal with a Superbike engine. High corner speeds can be maintained making the Honda the better of the two-stroke race rep pack, and by a large margin too. The ride is refined, very Latin in its smoothness and ease of use which, when allied to such a delightful engine, makes for a big grin factor that the other race-rep strokers only achieve by outright power.
On the move, the ride is typically two-stroke, despite the jiggery pokery that is designed to make the power band less abrupt, with a defined edge forming the transition from the lower to the upper rev ranges. Below 6000rpm there is little serious power to be had, it pulls enough to keep ahead of the traffic flow and produces a pleasant burble from the 3-exhaust end cans, however, once through this region things do start to get interesting with the needle taking a brisk run around the tacho face all the way to the engines speak power delivery at 9500rpm. It’s the same story in each of the six gears with the willing triple straining at the leash, eager to let the rev counter needle get intimate with the redline marker. Once at speed the whole show can be hauled up quickly, thanks to the twin discs up front, although sustained hard use does show in severe brake fade that requires a brief cooling off period. This isn’t helped by the large fork shrouds that clothe the brake calipers and prevent a blast of cool air from getting to them to aid heat dissipation.
The only let down is the standard exhaust system, it sounds weak and muffled, sadly missing that staccato cackle reminiscent of high powered two strokes. As the revs rise, the exhausts lack of excitement does making the bike sound slow and lethargic, thankfully it isn’t and a quick glance at the speedo soon reveals the truth. The NS isn’t the bike to own if economical fuel consumption is a must have, even if treated with kid gloves the engine has a healthy thirst, with a best figure to be had around the 30mpg mark and a far worst than that if the taps are fully opened for any length of time.
Honda NS400R Model history
The design took two years to come to fruition and was built with little regard for the race machine, having been based around the MVX250 triple of 1983. The engine is completely reversed when viewed along side the track machine with the road bike having two of the three cylinders laying horizontal, facing forward while the remaining single pot stands upright. There may be several reasons for this decision not least being the need to place important road going paraphernalia, like batteries and air filter boxes, within a small chassis but these were the same set of problems faced by both Suzuki and Yamaha who also had an extra exhaust pipe to deal with too, and yet they remained true to there racer roots.
The NS400R did take on the latest hi-tech advancements in chassis design with anti dive TRAC front forks, actuated by the left hand side brake caliper and a sturdy lightweight alloy frame. The NS400R wasn’t a success due to high prices and it relative lack of performance, being stuck in a no mans land sandwiched between the full on 500cc machines and the RD350LC. Today tidy examples of the Honda do command high price and are increasingly hard to get hold of, as indeed are some consumable spares like crank parts and bearings.
Honda NS400R Timeline
1983
Freddie Spencer wins the 500cc world title on the unlikely triple, having to rely on sheer determination and hard riding, when all around had more powerful 4-cylinder machinery. A 250cc triple is commissioned to celebrate the race track success, styled akin to the Honda VF range of four strokes the quarter litre machine wasn’t an official import into the UK.
1985
Honda release a road going version of the race machinery albeit with a capacity 100cc less.
1986
The game is up and arguably the finest and most complex road going two-stroke ever built is no more. Honda did continue to produce two-stroke machinery with the stunning NS250R twin but the multi cylinder race replica was to be no more.
1985 Honda NS400R Specifications
- Engine – liquid-cooled 3-cylinder 2-stroke
- Capacity – 387cc
- Bore/stroke – 57 x 50.6mm
- Power – 72bhp @ 9500rpm
- Torque – 37ft-lb @ 8500rpm
- Carburetion – 3 x 26 mm Keihin flat slides
- Transmission – 6-speed, wet clutch, chain final drive
- Frame – Box section alloy
- Suspension – 37mm telescopic forks TRAC anti dive. Pro-Link rear
- Brakes – 256mm discs, 2-piston, floating-calipers. 220mm disc, 2-piston, floating-caliper
- Wheels – 100/90 x 16, 110/90 x 17
- Weight – 163kgs
- Top speed – 135mph
- Wheelbase – 1362mm
- Fuel capacity – 19ltrs
Honda NS400R Gallery
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