Bimota KB4 and KB4RC By Ben Purvis
It has been two years since Kawasaki ' s surprise announcement that it had bought a 49.9 % stake in Bimota , and now we ' re seeing how the pairing will work going into the future - with the new KB4 and KB4RC going back to Bimota ' s earliest traditions of wrapping stock Japanese powertrains in a sharp-handling chassis . Although the Tesi H2 was revealed alongside the Kawasaki deal , combining the supercharged H2 engine with Bimota ' s hub-steered Tesi chassis concept , the KB4 is a much more representative model . Its title follows directly on from the KB3 of the early 80s , and since Kawasaki looks set to provide all Bimota ' s engines for the foreseeable future , we can expect a KB5 , KB6 and more to follow on without the near 40-year gap between the last two Kawasaki-powered Bimotas .
Kawasaki ownership makes its mark
Bimota built its brand around the idea of transplanting powerful , reliable Japanese engines of the 1970s from its original , uninspiring frames into stiffer , lighter bikes , but that niche was eroded as Japan ' s bike makers learnt how to make their own bikes handle well . With the KB4 and the naked KB4RC ( for ' Race Café '), the company goes back to the same idea , employing some radical thinking to regain the edge in terms of handling and weight reduction .
While the bikes take their 1,043 cc four-cylinder engines from Kawasaki ' s Ninja 1000SX , leaving them completely unaltered so they still pass emissions tests without extra expense , the 140 hp motors are bolted to a chassis that radically reduces the bikes ' wheelbase - repositioning the radiator to a new spot under the seat . That means the front wheel can be moved back , leading to a short , 1,390 mm wheelbase and shifting the mass of the engine towards the front , all while retaining a long swingarm for good traction . Side-mounted ducts take air to the radiator . The frame itself is part steel tube , part billet aluminium , with a purpose-made alloy swingarm and the usual combination of Öhlins and Brembo components for the KB4 , while the KB4RC has been shown with Marzocchi suspension .
Reborn BSA Gold Star
Norton and Royal Enfield aren ' t the only famous British bike brands to be under Indian ownership . Another legendary name - BSA - is part of the Mahindra empire and being revived with a new machine to bear the Gold Star name . Clearly putting its sights on Royal Enfield , the new Gold Star is a 652 cc single-cylinder , making 45 hp at 6,000 rpm to fit into the A2 licence category , with 55 Nm of torque at 4,000 rpm , driving through a suitably old school five-speed transmission . Despite the prominent cooling fins on an engine that ' s designed to physically resemble the air-cooled , pushrod Gold Stars of old , the new engine is actually water-cooled , and twin overhead cams lurk in the cylinder head , operating four valves . That engine is mounted in a traditional steel chassis , with conventional 41 mm telescopic forks and twin rear shocks , adjustable only for preload . That combination makes for a bike that weighs 213 kg ready-to-ride , with a full 12-litre tank of fuel . The modest tune of the Euro 5-compliant engine means it ' s rated for 70.6 mpg , enough to squeeze around 186 miles of range from a full tank . The spec includes single brake discs front and rear , each gripped by Brembo calipers , and 18 " front and 17 " rear wheels - wire , of course - shod in Pirelli
Phantom Sportscomp rubber . Straightforward dual clocks provide the info you ' d expect without the sort of smartphoneconnected excesses of many modern bikes , although there is a small LCD multi-function display alongside the speedo and rev counter . Initially , production is expected to take place in India , but Classic Legends , the company that owns BSA ( and itself 60 % owned by Mahindra ), also intends to build a manufacturing base near Birmingham to maintain the BSA name ' s links to the city . Classic Legends ' other brands include Jawa . The Gold Star might reflect BSA ' s past , but going into the future , BSA intends to develop an electric bike in the UK , where it has been awarded a grant by
the Government towards the creation of such a machine . In the shorter term , the Gold Star is due to hit the market in Spring 2022 , and while prices have yet to be revealed , they ' re expected to be competitive when compared to similarly sized rivals like Royal Enfield ' s 650 cc Interceptor .