The RCM Sanctuary A16R, the Z1000 for the new age. And boy, is it something to behold
Radical Construction Manufacture USA (RCM USA) has started to produce ultra-trick specials based around Kawasaki’s KZ1000 (Z Thou to us) under license fromac Sanctuary in Japan.the bikes, codenamed A16 and available in three base forms (A16R-RCM001, a ZI-R inspired street racer; A16R-RCM004, a naked black and gold caff-ish racer with drop ’bars; and A16S-RCM007, a red higher ’barred roadster with usd forks).
The heart of all three is a scratch-built 1045cc Zed motor, breathing through an electronic fuel injection system (essential in order to meet California’s stringent emissions laws) and a titanium four-into-one system fitted with a secondary air-injection system at the manifold, again to help the ’70s motor attain emissions regs.
As well as being built from the cases up, RCM claim to address a number of inherent weaknesses with the motor, replacing a number of components with upgrades, although they remain coy about exactly which parts.the stock motor’s bottom end is bombproof so we suspect the upgrades to include stronger valve springs and a manual camchain tensioner. Claimed power is 99bhp at 8000rpm and 66.5lb.ft at 6500rpm, compared to 83bhp and 55.8lb. ft of the stock Kz.that’s a healthy hike without making the motor into a peaky rev-monster.
The biggest change over the stock Kawasaki is the Sanctuary-engineered frame. Built from scratch from high-tensile tubular steel, and tested extensively in racing in Japan, the A16’s chassis keeps the original’s style while incorporating many modern twists.the headstock, for example, is not only fatter and much stronger than that of an original Kwak it’s also set 25mm further back and 30mm lower, reducing the bike’s wheelbase by 18mm.
More changes appear at the rear.the subframe is all new, as well as shorter.the top shock mounts are positioned several inches forward of where Kawasaki fitted the KZ’S. Complementing this change is a swingarm pivot (20mm in diameter to match modern practice) 10mm lower than on a KZ.THE swingarm itself is an achingly beautiful, under-braced Sculpture item fashioned from box-section aluminium. Shocks are fully adjustable Öhlins piggybacks. Both R models run rwu Öhlins teles; the S wears usd forks, again Öhlins.
We could swim for days in the details alone. No expense or pure engineering solution has been spared in building these frankly pornographic machines.you won’t get change from £30K for one of these either. But as good as they look, they’re for riding too, so PS sent Japanese test rider Ryuji Tomono along to RCM to try the A16 for himself. Needless to say, he wasn’t disappointed.
RIDING THE A16
The Kawasaki KZ, successor to the legendary Z1, has been loved, customized and upgraded by custom-builders from around the world for the last 40 years. Current trends favour these classic superbikes on wide 17-inch wheels, to maximise sticky tyre choice. But this isn’t without its problems.this extra grip and change in wheel profile can cause instability on these older chassis. Japan’s AC Sanctuary and now California’s RCM say they have the answer for this blend of classic style and modern engineering. The A16.
The essence of this machine is performance, pure and simple, and RCM’S goal when building the A16 was to maximise the synergy between old and new. The moment I swung a leg over the A16’s seat and put my hands on the clip-on ’bars, I felt it fitted me perfectly.adding clip-ons to this type of classic superbike can make the rider lean an uncomfortably long way forward, almost crouching over the fuel tank just to reach the controls. But the A16 is different. RCM alter the head stock (which is fatter and stronger than stock) and position it to sit 25mm further back and 30mm lower than on the Kawasaki Z1000 chassis. So despite racey ’bars the riding position is comfortable and natural yet purposeful, even for smaller riders.
RCM’S frame dimension tweaks don’t end there.thea16’s swingarm pivot is positioned 10mm lower than that of the Z.along with strategically placed bracing,
these chassis changes make for a much stiffer frame than the original Kawasaki item. Not only that, the centre of gravity is lower, giving the bike a more centralized mass again improving control and feel for the rider. Handling is further aided by a substantial reduction in weight – the A16 is a full 44 kilos lighter than a Z1000.
When I turn on the ignition and push the starter button, the engine wakes up from a sleep as fuel mixture sprays through the inlets into the combustion chamber from the electronic fuel injection system (itself a response to California’s stringent emissions legislation).the raw bark from the aircooled two-valve unit pops with nostalgia, yet the crisp and instant throttle response gives the unit an edge of modernity. It’s an intoxicating blend of old and new, especially for those who have fond memories of these Kawasaki powerplants from back in the day.
Once on the move the fully rebuilt engine responds well. RCM haven’t gone for huge power, rather usability.with 99bhp and 66lb-ft of torque to hand there’s more than enough performance to draw from. But unlike modern engines the A16 retains its old school vibe and charm and, in doing so, reminds me of my adolescent enthusiasm for these bikes. Radical tuning can spoil the character of these 1970s dohc motors, especially for the road. Retaining the rich seam of torque is essential for that all important drive out of bends.
Although the sensations and classic feel are there with the motor – it’s still got a big, heavy crank so it produces power like a building wave rather than the spinning turbine effect of a modern engine – the handling and road manners of the A16 are far more up to date. I don’t have to plan well ahead just to get the thing around a corner.
Our test route took us through some very challenging, winding roads, where a proper classic Z1000 would be a real handful.these old timers with their skinny tyres, basic suspension, limited braking performance and heavy mass require big inputs from the rider and deliberately smooth arcing sweeps through the turns to give their best. Aboard the A16 however, I felt as if the bike was guiding me. On a Zed you need to pull the bike through the corner and lean with it to hold your chosen line – they’re a very physical ride.thea16 removes that effort and responds equally well to a classic style or a more aggressive supersport type input. The chassis remained planted and continued to relay feedback even when I dragged the front brake into and through a corner – not something I would try to attempt on a period Zed.
I never dreamed an air-cooled four-pot
“ON A ZED YOU HAVE TO PULL THE BIKE THROUGH THE CORNER AND LEAN WITH IT. THE A16 REMOVES THAT EFFORT”
engine held by a steel tubular frame would perform like this. I increased the speed, but the A16 never disappointed or lost control. All of my inputs were rewarded with accurate and predictable results. It turned so cleanly and accurately largely because of that altered steering angle. By comparison a normal Z falls into a turn, then struggles to pull itself through and out the other side because of the high-centre of gravity and high roll-axis.the changes RCM make to
the A16 frame completely transform the handling characteristics, and move the ride on by several decades.
The real test for this RCM frame is its ability to allow the bike’s high-grade componentry to shine. Parts like the stateof-the-art Öhlins forks, radial-mounted Brembo calipers, and lightweight OZ Racing aluminium forged wheels would easily overwhelm a standard Z frame, causing it to respond and handle perhaps even less accurately than with original parts.thea16 runs nimbly through winding roads almost as if it’s dancing.
As you’d imagine the suspension gives a plush, composed and compliant ride, and rider feedback is as good as on a top level supersports machine. Steering and turn-in are light and responsive thanks to the OZ wheels, and braking is exactly as strong as you’d expect from a radial Brembo set up. Two digits are all that’ll ever be required on the lever.
Once on 17-inch wheels a bike with a strong, taut frame, like the A16’s, will accept a modern riding style. But even so, when cornering after braking hard, it’s not uncommon to experience understeer as the stresses put through the frame and steering stem from sticky rubber and compliant suspension can often overwhelm even an updated and improved chassis. Surprisingly, however, the A16 is free from any such antics.the steering is not that far off that of a modern supersports machine. Combine that with the feel and force of the big twovalve motor and the A16 is a real joy to ride.and to ride fast.
AND WHO IS RYUJI TOMONO?
A Japanese race school instructor, and freelance writer for electronic and print magazines.
Loving that snakey exhaust mounting bracket (and the rest)
Top: Engine architecture that has truly stood the test of time. If it ain’t broke... Above: Computer design shows the RCM’S stumpier wheelbase compared to stock KZ
Fuel injection replaces carbs. Looks OK though
They didn’t hold back on the candy in the paint
Yes, it’s bloody lovely
Eager to turn where an old school Zed would protest
Push hard on a traditional Zed and you’ll know about it. The A16 just gets on with things
Tomono (centre) with some of the RCM crew