A contemporary incarnation of Praga BD 500…
In 1928, the primary Praga BD 500 rolled out of Prague’s Breitfeld-Daněk manufacturing unit — a really trendy motorbike on the time, that includes what is alleged to be the first manufacturing twin cam motorbike engine.
It was the brainchild of a younger Czechoslovakia aviation designer and passionate motorcyclist, Jaroslav František Koch, who was satisfied of the potential of overhead cam engines. In 1923, J.F. Koch had produced his first motorbike, the JFK, which boasted a 350cc OHC engine with a longitudinal crankshaft.
In 1926, he went to work for the BD (Breitfeld-Daněk) motorbike works of Prague, the place he designed a 500cc “double-knocker” twin-overhead-camshaft, 84 mm x 90 mm, unit-construction single-cylinder engine.
The engine made 15 hp at 4400 rpm, robust sufficient to push the 170-kg BD 500 as much as 65 mph, and made fairly the splash within the motoring world:
“The BD 500 not solely introduced a number of modern design options, however earned its place in motorbike historical past when Koch himself rode the bike from Rome to Prague, overlaying a distance of 1,480 kilometers in 35 hours and 40 minutes, setting a brand new endurance file.”
At the moment, motorbike collectors and historians nonetheless maintain the BD 500 engine in excessive regard:
“Completely excellent…so good that it had nice success in most branches of motor cycle sport, regardless of being produced within the comparatively small numbers related to such high-end engines.” –Bonhams
Now, in 2023, historical past is repeating itself with the introduction of the Praga ZS 800 — a contemporary incarnation of the enduring BD 500. It’s the work of one other sensible Czech engineer, our good friend Jan Žuži, whose work we’ve seen in his carbon KX500 and Jiří Heiník’s KTM 1290 Tremendous Enduro R.
Recently, Jan has been engaged on the Praga Bohema, a 700-hp / 2164-lb / £1.1m Czech hypercar with a carbon fiber monocoque chassis and Nissan GT-R energy. Nonetheless, his two-wheeled roots quickly known as him again.
“The brainchild of Jan Žuži, an engineer engaged on the light-weight 700 hp luxurious Praga Bohema hypercar, the ZS 800 started life as a ardour venture to create a BD 500 remake.”
Working with fellow engineer Radek Šebesta and others from the Bohema workforce, chief designer Jan mixed his engineering experience and fervour with Praga’s superior motor racing manufacturing processes, supplies, and racing know-how to recreate a Czech motorcycling icon for the twenty first century:
“The Praga ZS 800 was born, a contemporary reimagining that retains the character and design of its ancestral BD 500.”
Highlights embrace a chrome molybdenum metal body, ultra-lightweight titanium exhaust system, distinctive hand-woven carbon wheels, hydraulic drum brakes, sculpted entrance fork with absolutely adjustable Öhlins suspension and titanium spring, Öhlins suspended saddle, and a 773cc air-cooled four-stroke parallel twin engine with bevel gear cam drive and Euro5 compliance.
Greater than 300 hours of five-axis machining is alleged to enter each construct, and the in depth use of superior light-weight supplies means the ZS 800 weighs simply 142kg (313 lbs) dry.
What’s extra, the bike boats 50:50 weight distribution between the wheels — mentioned to lead to a markedly poised experience. Says Jan:
“Robust and intensely light-weight supplies — corresponding to carbon, titanium, chrome molybdenum metal, and aviation duralumin — enabled us to reimagine the inflexible rear wheel suspension, the entrance swingarm fork, and the hydraulic drum brakes. These futuristic supplies and Praga sports activities division’s newest manufacturing services have enabled us to switch these elegant historic design components to the current day, and to construct a bike with up to date driving traits and a singular really feel.”
To us, the BD 500 appears like a exceptional fusion of basic design, motoring heritage, and essentially the most cutting-edge design, manufacturing, and supplies out there as we speak. We’re extremely pleased with Jan Žuži for utilizing his expertise and fervour to reimagine one in every of his nation’s motoring icons.
Praga plans to provide simply 28 examples of the ZS 800, now out there to order with deliveries beginning mid-2023. The price is £75,550 (€86,000) every — Praga says the value is a testomony to the intricate engineering that goes into each one in every of their creations, together with the £1.1m Praga Bohema hypercar. To study extra, head over to www.pragaglobal.com/motorbikes/zs800.
Praga ZS 800: Highlights
The ZS is loaded with attention-grabbing supplies and manufacturing options. Listed here are a couple of particulars that caught our eye.
“Titanium is used all through the design, with nearly each screw, axle, nut and bolt of the chassis and engine constructed from the light-weight, excessive energy steel. The exhaust system can also be absolutely titanium and weighs simply 4.8kg consequently – with choose components constructed utilizing state-of-the-art 3D printing. Premium supplies corresponding to duralumin alloys, noble chrome molybdenum metal and solid carbon are additionally integrated into the ZS 800’s design.”
“The ZS 800’s distinctive solid carbon wheels work in concord with its hydraulic drum brake system – a system chosen to enhance each the motorbike’s type and efficiency. The hand-woven carbon rims are a fancy creative sample of overlapping carbon fibre with intricate carbon tensioned spokes to emulate the look of the BD 500.”
“A sculpted entrance fork sits on the fore of the motorbike; a construction solely made attainable by five-axis machining and chrome molybdenum metal. Nestled throughout the fork is absolutely adjustable Öhlins suspension with a titanium spring that effortlessly delivers a clean and unique experience.”
Based in 1907, Praga has produced cars, plane, buses, trolleys, motorbikes, mild tanks, artillery tractors, and even the V3S 5-ton truck that the Czech army used for greater than 50 years.
Manufacturing led to 1947, however restarted in 2011 when Praga produced the R4S, a light-weight 400-hp race automotive that lapped the Slovakia Ring in 1:59, beating Lamborghini’s Gallardo GT3 Supertrofeo LM GTE racer by three seconds.
At the moment, Praga has continued its racing heritage with machines just like the Praga R1, a sportscar with a carbon fiber monocoque chassis that raced within the Britcar Endurance Championship, and the brand new Praga Bohemia hypercar.
Comply with the Builders
Chief Designer, Jan Žuži: jzhandmade.artwork | @jzhandmade.artwork
Praga: pragaglobal.com | @praga_cars | Fb.com/PragaCars/