Retrobike Issue 41

IF LAST issue was our six-cylinder special – we ran two, a Honda CBX1000 and Kawasaki Z1300 – then let’s dedicate this one to the mighty two-stroke. These days mostly confined to chainsaws and the like, two-stroke engines were a mainstay of motorcycle propulsion for the best part of a century before falling foul of environmental legislation in the new millennium. “Two-strokes were a mainstay of motorcycling for a century” At first glance, Phil Rowe’s Yamaha RZ on page 64 and Sammy Miller’s Maico Taifun on page 84 could not be more different, but both are powered by 350cc two-stroke vertical twins. The liquid-cooled 1985 Yamaha is the quintessential boy racer, the air-cooled 1957 Maico a luxurious gentleman’s tourer. At the birth of internal combustion engines, the four-stroke was first…

SOME people are good at picking their parents, like Melbourne’s Scott Gercovich, the creator of this tough urban bruiser. “I’ve had a passion for all things two-wheeled since I got my first bike, a Honda Z50R, when I was about five,” he says. “But of course, as you grow older, the bikes got bigger until I could finally get my motorcycle licence and buy my first road bike. I have never looked back.” That journey eventually led the now 46-year-old Scott to hyper sports bikes like the Honda CBR954RR and BMW S1000RR, until an overwhelming urge to scratch an itch took him down a different path. “I’ve always had a fascination with café racer builds and really wanted to have a go at transforming a standard road bike into one,”…

BMW turned its back on 60 years of carburated air-cooled OHV flat twins when it released the fuel-injected liquid-cooled DOHC four-cylinder K100 inline fours in 1983. It was a radical design, with the engine lying on its side – the cylinder head on the left and the crankcase on the right – but with crankshaft running north-south in typical BMW fashion to allow shaft final drive. The ‘lift-off’ space-frame chassis was equally innovative, not least the single-sided swingarm which predated the Honda RC30 by four years and the Ducati 916 by more than a decade. The first K100, a naked-style bike, was soon joined by the fully faired K100RS and K100RT, and eventually the K100LT luxo barge in 1986. The engine was upgraded from two valves per cylinder to four…

ENGINE Liquid-cooled four-stroke inline four; chain-driven DOHC, four valves per cylinder; 70.5 x 70mm for 1093cc; 11.0:1 comp; Bosch Motronic ECU; wet sump; K100 headers, Café 4 Racers collector and right-side conversion pipe, Termignoni muffl er; dry single-plate clutch to five-speed gearbox; shaft final drive; 100hp at 7500rpm (stock) CHASSIS Space-frame chassis in tubular steel, fairing tabs removed; shortened seat sub-frame; sandblasted and finished in Dulux semi-gloss black; 41mm conventional telescopic forks, twin 305mm Arashi wave rotors with Brembo four-pot calipers on 18in alloy wheel; single-sided Paralever swingarm, single 285mm Brembo rotor and twin-piston caliper on 17in K1200 alloy wheel BODYWORK Stock tank; custom seat and fibreglass mudguard; Starlight Black paint; Koso Thunderbike headlight; Motogadget dash WANT MORE Go to twistedfatebuilds.com for detailed build pics BEST Amazing first-time shed build;…

“THE ALUMINIUM BODYWORK WAS SCULPTED BY HAND-USING TRADITIONAL TOOLS” THERE are many reasons why this UK-built café racer hits our buttons. It’s powered by an air-cooled Ducati, always a good start. The design is innovative and elegant, and the metal craftsmanship outstanding. And it was all built at nights and on weekends by one man working in his well-equipped shed. Jim Alonze is a 35-year-old welder from Scarborough specialising in bespoke two-stroke exhausts and one-off fabrication. As a hobby, he builds motorbikes under the banner, Alonze Custom. “I got my first bike when I was seven and loved them ever since,” he says. His stable is an eclectic one, currently comprising a Buell XB9, a Yamaha RD350 flat-tracker, a 1954 Triumph chopper and a Ducati 600 custom that first brought…

ENGINE Air-cooled four-stroke 90-degree V-twin; belt-driven desmodromic SOHC, two valves per cylinder; 88 x 61.5mm for 748cc; 9.0:1 comp; wet sump; electronic injection and ignition; custom titanium exhausts; gear primary drive to multi-plate clutch and five-speed gearbox; chain final drive; 62hp at 7500rpm (stock) CHASSIS One-off brazed and welded trellis chassis in mild steel, nickel-plated; Yamaha R6 conventional forks in custom trees; fabricated monoshock swingarm in mild steel, nickel-plated; custom hubs with inboard disc brakes, laced to 3 x 18in alloy rims; Avon tyres BODYWORK Custom one-piece tank and seat unit, nose fairing and front mudguard all handmade in aluminium; leather seat and grips; Motogadget Chronoclassic clock BEST Peerless style, workmanship and presentation; innovative chassis and brakes NOT SO GREAT Nothing…