BRIDGESTONE 350 GTO
Steve Cooper on the tyre-maker’s masterpiece.
You always hear journos talking about ‘The Big Four’ Honda, Kawasaki, Suzuki and Yamaha, but after the Second World War, there were scores of Japanese firms turning out motorcycles. As the 1960s dawned there was a period of profound acquisitions, mergers and takeovers which saw many previously strong brands absorbed within that quartet of big names. As the 60s came to an end only Bridgestone remained resolutely producing stunning motorcycles which challenged the very best quality of their much larger rivals. For many, Bridgestone’s finest hour came circa 1967 with the arrival of two new twin-cylinder ranges in 175 and 350cc. The company habitually majored in superb quality finishes and high-end technology but traditionally had focused on what we’d now affectionately term as tiddlers. The 175cc Dual Twin and Hurricane machines totally outclassed the opposition but it was the 350 bikes from Bridgestone that really grabbed the headlines. With a claimed 37 horses at 7500rpm the factory reckoned their bikes were good for 95mph. At the time this was seriously fast but when our forerunner (Motorcycle Mechanics) road tested it at 108mph everyone who knew anything about bikes knew this was something really special.
The 350 twins were available in both roadster and street scrambler guises and it’s the latter format, known as the 350 GTO, which sits resplendently in camera this month. The whole street scrambler scene was created on the back of the desert sled off road racing that was so popular in the USA during the 50s and 60s. Road bikes were stripped and modified to be dirt compatible and it was Triumph that are generally acknowledged as being the first to offer a factory built analogue. Obviously the Japanese factories weren’t going to miss out on a chance to sell more machines into a niche market so happily jumped on the band wagon. Bridgestone were in there like a shot. Although ostensibly little more than the road-going 350 GTR with a minor makeover the GTO variant is ultimately harder to restore. Items such as the exhaust system, the front guard and handlebars are all unique to the street scrambler. That said neither the GTO nor GTR are what you’d call conventional: their common, twin cylinder, engine unit runs disc-valve induction; something only seen on Kawasaki A1s and A7s of the period. Pretty much unique among bikes of the time are the chrome plated cylinder bores. The reason for this once again comes back to Bridgestone’s innate desire to offer the best quality solution for any application. A thin deposit of hard chrome direct to the alloy cylinder meant, in theory at least, that tighter piston ring clearances could be utilised which in turn would facilitate better performance. If the Motorcycle Mechanics road test is anything to go by you’d argue it was mission accomplished. Elsewhere the bike is relatively conventional but it has to be borne in mind that the first off models are now 50 years old which means they were designed and drafted up circa mid-1965 so, when the bike was new, it was unquestionably cutting edge stuff. Why would you want a 350 GTO now? Look at the pictures and ask that question again! Even if street scramblers aren’t necessarily your thing it’s hard to deny the lines of the bike are anything other than stunning. As the saying goes the devil is in the detail and with a GTO the more you look the more you see. Remembering that this was a machine produced by a relatively minor league player (some sources suggest an annual production run of less than 10,000) the level of commitment and specification is stunning. The oil tank is a plastic moulding, something the likes of Yamaha wouldn’t adopt for years. There are wire spring protectors on the oil pump and tacho cables, a suede effect seat cover and stainless steel guards. The tool box is a minor work of art and how about lubrication points to the cables or that double cleat up by the clocks that holds the cables in place? And if that wasn’t sufficient check out the rear brake and gear pedal. Bridgestone was keen to satisfy all markets so engineered both engine and frame to facilitate left foot rear braking and right foot gear changes; the Big Four never paid that sort of attention to detail. Bridgestone stopped motorcycle production late 1971 but those that recognise a quality machine will tell you quality never goes out of fashion: which is a good enough reason to want to own an iconic 350 GTO!