What is a JZR? Is it a 1930's Morgan Aero Sports? - NO! IT’S A ‘JZR’ A modern ‘KIT CAR’ tricycle powered by a V-twin motorcycle engine
The JZR is a car kit with a steel chassis and fibreglass body which uses a motor bike engine as its power. The idea for this car came from 1930’s MORGAN Trike and was designed by John Ziemba of Darwen.
The chassis is designed individually to fit different engines. The most common engines used are Honda, CX500, 650 and Pan European 1100cc, the Moto Guzzi and Harley Davidson. Any V twin or small V4 engine would probably be able to be fitted into a chassis by John.
The upper body front and back is fibre glass and it has a steel chassis and skirt. It comes in a long cockpit (some older CX500 comes with a short cockpit and would be suitable for someone 5'6" or less). They are tailored to fit the various engines and can even be supplied with bulges at hip and footwell to accommodate pilots. The kit is supplied with an extended shaft to reach the back wheel. With RHD the tunnel is slightly to the left, making the driving side narrow. A LHD gives the driver more room.
The Hondas are water cooled and the Moto Guzzi are air cooled. Its cheap insurance ( typical £130 per year), Cheap tax £65. Cheap to run @ 50mpg unleaded
About 360 of these kits exist world wide, but the Honda CX500 engines aare getting rare so these days you can fit HARLEY DAVIDSON, MOTOGUZZI, CX650 & TURBO OR HONDA PAN EUROPEAN 1100cc V4. The latest prototype is based on a TRIUMPH DAYTONA
A typical JZR could contain a1978 HONDA CX500 MOTORCYCLE, A JZR KIT, FORD CORTINA uprights, FORD MEXICO steering rack, FIAT steering column, MGB WIRE WHEELS and KNOCK ON’S, and a assemblage of parts to represent the Morgan -After all inthe thirties Morgan used JAP engines (‘JOHN A PRESTWICH’)so the kit uses a JAP engine (as in MR‘HONDA’)
Commonly used power plants for JZRs( More detailed specifications for each will be on the web later)
Triumph Daytona 3 cylinder
AH Grasshopper - a good comparison from member Keith Bull who has had many years of experience in three wheelers
In Webmaster Choice, Brian invited contributors from members in response to the mail from Arlen C. Moore of Oregon asking for a comparison of the performance of Honda, Moto Guzzi, and 2CV powered cars. My own experience over the last seven years has included a Lomax, (2CV), BRA CV3 (2CV), JZR Barrel Back (Honda CX500), and a Pemberton Grasshopper (2CV). So as you can see I've had some experience of the plus and minus points of the various types.
The Lomax and the BRA both suffered from excessive roll. Anti-roll bars and adjustable shocks added to their stability but sharp left hand corners still raised the pulse rate!
The lowering of the chassis in these cars upsets the steering geometry. This is not a crucial problem but they do have excellent straight line stability off set by heavy steering loads when cornering.
However, these cars are not built with weight saving in mind, except to meet the 410kg limit. Thus the performance is not electrifying, but is adequate. The 2CV engine is very robust, reliable, and above all, cheap and simple to maintain. They also have a reverse gear!
The JZR CX500 came as a revelation. Brilliant good looks, superb cornering with no roll at all to speak of, excellent steering (although I know some people have had ‘bump steering’ problems. Of course it has the five speed gear box, good performance and that mean, low ‘engine-in-your-face’ appearance which I craved.
The down side of the JZR CX500 is well documented, liquid cooling, overheating of both engine and driver, no reverse, small driver hip room, and high cost of Honda spares and repairs. However, it certainly is a ‘drivers car’, well worth the agro, and I even enjoyed every minute of it! The ‘new project’ bug then bit again and I reluctantly had to sell the Lomax and the JZR to make ‘building room’.
The Pembleton Grasshopper Super Sport had appeared on the market so I went to see the designer. As an ex-motorcycle racer, who had designed and made his own bikes, he looked to weight saving and road holding as basic crucial ingredients of any performance vehicle.
Thus the Hopper has a tubular space frame with an integral chassis sub-frame. The engine is suspended from the bell housing thus doing away with any chassis forward of the axle tube. The front axle suspension arms are corrected for both camber and caster angle thus ensuring near perfect steering at a ride height of 4 inches. The rear suspension system uses 2CV parts and is both simple and weight saving. The 2CV main suspension springs are used, but by ‘chocking out’ coils using inserts the rates can be adjusted to suit your ride requirements. The body is all aluminium generated from flat sheet 0.9mm thick on the ‘regular’ specification. I used 1.5mm thick for extra stiffness, and this turned out to be a masochistic build decision and added some 10 o 12kgs to the weight. I left the body in polished aluminium finish.
The engine uses two Honda 250N Superdream carbs with larger main jets, and these give a progressive increase in urge unlike the twin choke Solex normally fitted to the 2CV.
My finished car tipped the scales at 360kg giving it a theoretical power to weight ratio of 100bhp per ton!
On the road the car handles exactly like the JZR. The centre of gravity must be on or below the axle centres as the car corners dead flat without the use of an anti-roll bar or special shocks. The top speed and general performance, on Shell Optimax, is more then adequate and compares favourably with the JZR. There is the question of front or rear wheel drive to consider. My own view is that front wheel drive is the safer of the two. Driving down a narrow country road with the single rear drive wheel scratching for grip and weaving from side to side on a mound of wet moss, weeds and unmentionable droppings can be both exciting and off putting.
Finally the Hopper meets my criteria for a low, mean looking trike. The engine is entirely exposed, and air cooled boxer twin, leaving nothing to the imagination, and, with wires, it looks the part.
The combination of low tech reliability and striking looks have meant that 90 or so kits have been sold in just over two years at a basic cost of £1000 each including all the modifications to the 2CV parts. It has been sad that you can put one on the road for as little as £1500. I note that Brian says that we won’t venture into Citroens, but I've seen him at several CSC meetings in his JZR and he looked perfectly happy, if a little superior!
My view is that we are all infected with trikomania and it never hurts to see what the other fella is doing. In the end you pays your money and you takes your choice. You see I kept the BRA CV3 as a stable mate because I'm also a mug for long bonnets and it's always useful to have a spare car.
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