The birth of the legend
If only motorcycles could talk. Were that the case, it would make the process of ascertaining just how this ultra-rare Honda came to eventually end up in The Netherlands, after its constituent parts were scattered far and wide over more than sixty years. So let’s go back to the beginning of this saga, to the Isle of Man TT of 1959.
All this had come about as a result of a visit to the island in 1954 by Soichiro Honda himself, who had earlier in the year announced his intention to one day field a team on his own products in the world’s most famous and important motorcycle event. It took five years for that notion to become a reality, but in January 1959 Honda sent a delegation to UK for meetings with the TT promoters, the Auto Cycle Union of Great Britain, and to visit the island to inspect the TT course. This delegation consisted of Honda engineer Ichiro Niitsuma, and American William J. ‘Bill” Hunt, who was officially described as a Honda Staff Adviser. Later in 1959, Honda took the bold step of opening its own sales/administration office on West Pico Boulevarde, Los Angeles as it took aim at the US market. As well as racing in USA, Hunt had spent some time in Japan, and in 1958 won the Japanese National Championship at the Mount Asama course on a 650cc Triumph.
The pair told the ACU that the intention was to enter three DOHC Honda twins in the 125cc TT, plus a stock SOHC Honda Super Sport model for Hunt. Niitsuma told ACU officials that the race bikes developed 18.5 bhp at 13,500 rpm and weighed
approximately 90kg. In the Isle of Man, the Honda pair met with former World Champion Geoff Duke, who took them for a tour of the ‘Mountain’ circuit. Hunt made arrangements for the team to stay at the Nursery Hotel in Onchan (booking out the entire guest accommodation) which, conveniently, was located on the shorter 10.8 mile Clypse Circuit that would host the 125cc TT, as well as the 250 and Sidecar races. The hotel also had out-buildings to house the bikes and equipment and had been used by many teams, including Velocette, over the years. This was to be the first Japanese participation in the TT since 1930, when K. Tada finished 15th in the Junior 350cc TT on a Velocette.
Four months later, the Japanese squad arrived for the races. It has been said that nobody took too much notice of the Honda team as they set up at their digs at the Nursery Hotel, but that is untrue.
The sight (and sound) of a dozen Japanese – riders, mechanics, and even a cook to prepare food brought with them from Japan – was certainly something out of the ordinary for the little island in the Irish Sea. By this stage, the squad had grown somewhat, to five riders, all on RC141 models, and Hunt was now on one of the racing models after it became clear that the road CB92 Benly would be outclassed. As well as the race bikes, Honda sent four of the 125cc Benly twins to use as training bikes and ground transport. They also sent a box containing promotional items such as caps, badges and even battery powered wireless sets, but after a visit from the Customs and Excise people, were prevented from giving these out as they had not been declared on entry. All the mechanics wore freshly-laundered overalls and white woollen gloves. Controlling the project was Kiyoshi Kawashima, who went on to become president of Honda Motor Co. Ltd. All but one wore a jet-style helmet instead of the traditional ‘pudding basin’, and Hunt especially stood out with a plastic bubble enclosing his face – what was termed by the press “a space man visor”. All members of the Honda squad carried passports indicating they were temporary employees of Okura Trading Company, Japan, an importer/exporter, which was felt would ease red tape and gain permission to travel.
Compared to the European opposition, the Hondas, designed by Tadashi Kume and Kimio Shimmura over the previous two years, were certainly unusual looking. It has been widely fancied that the RC141’s power plant was a copy of the NSU twins of the early ‘fifties, but this is hardly the case. It is true that Soichiro Honda undertook a European tour in 1954 and visited several factories, including NSU and Mondial, and arrived home in Japan with a pair of suitcases bulging with various bits and pieces, but the little 125 Honda was basically original thinking. Recalling the project to quickly produce the RC141, Kiyoshi Kawashima recalled that a 1956 model F.B. Mondial was acquired from Italy in 1958. “We learned a lot from it,” he said. “I could say that we were able to build our first Isle of Man TT competition racer thanks to that machine.”
Like the Mk2 NSU Rennfox racers, the camshaft ‚
“I could say that we were able to build our first Isle of Man TT competition racer thanks to that machine.”
drive was by bevel shaft on the left side, but to the exhaust camshaft rather than to the inlet camshaft as on the NSU. The engine was “over square” with 44mm x 41mm bore and stroke, the magneto mounted on the right side driven by the inlet camshaft, with horizontally-split crankcases and a six-speed gearbox with gear primary drive. A single 10mm spark plug was located in the centre of each combustion chamber in the one-piece heads, with separate cylinders. Uniquely, the special Keihin racing carburettors had flat slides. The engine was a dry sump design, with two litres of oil carried in a heavily finned bolted-on aluminium sump under the crankcases.
The frame was of the backbone spine type with the rear swinging arm pivoting in the engine plates, and leading link forks up front, with the fork links connected by a steel tube loop. The rear spring/damper units and the hydraulic dampers on the front forks were made by Honda. Both brakes were 180mm, with a twin leading shoe front and single leading shoe rear. Wheels were 19 inch at the front and 18 inch rear, both with alloy rims fitted with British Avon Racing tyres. Hand-beaten light alloy fairings had a double section, presumably for better air flow, forward of the rider’s legs. Inside the perspex bubble sat the single instrument, a Kokusan rev-counter calibrated to 14,000 rpm.
Virtually every bolt head and nut was drilled and lock-wired, but it was explained that this was simply a visual aid to ensure that each had been carefully tightened before wiring so no further checking between use would be required.
Track time
Practice began badly for Honda when Giichi Suzuki fell and broke a finger. Despite protests from the team and rider, he was ruled medically unfit for the race by the ACU medical staff. In the final practice session, Hunt had a lucky escape when the front brake of his RC141 locked with such force that it snapped the anchor arm and rotated the whole wheel so that the mudguard went underneath and acted as a skid. Miraculously, Hunt brought the machine to a standstill. This was later found to have been caused by a circlip that had dropped off the end of the shoe pivot and became wedged between the shoe and the drum. A redesigned part was airfreighted from Tokyo and fitted to all the race bikes prior to their event. In fact, Hunt had already expressed concern about the part and had cabled the factory earlier for the modified pivot pin to enable the shoes be held in place by washers and split-pins. Also airfreighted were three new 4-valve cylinder heads, which were still being machined when the race bikes had been sent. These were fitted to the Hondas ridden by Taniguchi, Giichi Suzuki and Junzo Suzuki while the other two stayed with the two valve heads. Unusually for race engines, the Honda components were die-castings rather than sandcastings. The designation for the 4-valve bikes was thus changed to RC142.
Practice had also shown that the Japanese riders (and Hunt) were well off the pace of the top Europeans. Searching for any competitive edge, they abandoned their diet of rice, eggs and fish prepared in the hotel kitchen by their own cook, and requested the owner of the hotel purchase for them a large quantity of steak. Reasoning that the riders who were beating them ate steak, this was what was required for extra speed.
After weeks of preparation and countless practice laps, the Hondas finally gridded up for the 10-lap 125cc Ultra-Lightweight TT on Wednesday June 3rd. Unlike the Junior and Senior races on the full Mountain course, the Clypse circuit events were massed starts. This was to be the final year that the shorter circuit was used. After a final entreaty to the
medicos, Giichi Suzuki was cleared to start, but as the field streamed away from the grid, the European machines were already in control. After one lap Taniguchi was the best of the Hondas in ninth position, with Junzo Suzuki, Giichi Suzuki, Hunt and Teisuka Tanaka further down the field. Hunt lasted only half a lap more before crashing out of the race, uninjured but with the Honda too badly damaged to continue. On lap seven the pin in the rear brake rod on Junzo Suzuki’s RC142 fell out and he was forced to pit for repairs.
At the completion of the 10 laps, Taniguchi held sixth and G. Suzuki seventh, the last riders not lapped by the winner Tarquino Provini’s MV Agusta. With a time of 1 hour 34 minutes 48 seconds and a race average of 68.29mph, 23-year-old Taniguchi received a coveted Silver Replica, while G. Suzuki and Tanaka (8th) received Bronze Replicas. J. Suzuki completed the Honda quartet in 11th place, sufficient to bring the highly-prized Team Trophy to the Honda Motor Co. Ltd. at its first attempt, defeating the might of the European MV, MZ and Ducati factories. However it was not lost on Honda that their top finisher was more than seven minutes behind the winner. More work was needed. Twelve months later, with the new RC143, Honda took second, third and sixth in the 125 TT, and in 1961, won both 125 and 250 races. Job done.
Many years later
With brand new machinery produced for Honda’s TT return in 1960, the RC141/2 was quickly forgotten. Immediately following the 1959 TT, the engines from the five race bikes were removed in the courtyard of the Nursery Hotel, packed into boxes and airfreighted back to Japan for the important National Road Race Championship. The chassis, spares, tools and the other equipment followed later by sea.
Bill Hunt hung up his helmet and returned to USA, where he took up a position in the sales office of the new American Honda Company in Los Angeles. The company had opened only one week after the 1959 TT, with Kihachiro Kawashima as manager.
A year or so later, one of the exotic 250cc 4-cylinder models, along with an RC142, was shipped to California to be put on display as examples of the company’s innovative engineering. The 125cc did ‚
the rounds of dealers and shows for quite a while before disappearing until enthusiast Peter Johnson discovered parts of it, including the engine, in a motorcycle workshop in Mississippi, USA. A deal was done and Peter took the engine home, probably wondering how he was to find the rest of the historic motorcycle to be able to restore it to its former glory. His enquiries in this regard put him in contact with Mike Buttinger, founder of Consolidated Motor Spares (CMS) in Amsterdam, who is a serious collector of early Honda racers (two of which have been featured in OBA). Mike had set up a business in partnership with engineer Marnix Deibert (who had worked in Australia for Ron Sumskis in Wollongong) and designer Sebastian van de Broek with the specific purpose of specialising in the restoration of Honda motorcycles and cars with historical significance.
The first stage of what has transpired to be a long and difficult process was to collect as much technical information as remains about the RC142. Such was the pace of development of Honda’s racing efforts in the 1960s, obsolete racers were quickly forgotten and rarely preserved. In the case of the RC142, almost fifty years passed before Honda decided, in the absence of a real one, to reproduce one example (plus a spare engine) from scratch to celebrate the half century. The reputed cost of this two-year exercise was US$1 million. It was completed in 2009 and fittingly, the man who demonstrated the little screamer at Honda’s Motegi circuit was Naomi Taniguchi, now 73 years old but looking fit and healthy. The RC142 was subsequently demonstrated by Marc Marquez at Motegi in 2016 and by former Honda works rider Stuart Graham at Goodwood in 2019. That motorcycle now occupies pride of place in the entrance hall of the magnificent Honda Museum at Motegi.
Meanwhile, in The Netherlands… Marnix Deibert’s small but impeccably neat and well appointed workshop has turned out many restorations and renovations, but few as challenging as the RC142. Having the engine was perhaps the easy part. For instance, there was just one of the very special Keihin flat slide carbs with the engine; the second had to be made from scratch, and in mirror image to the existing one. The magneto had also to be machined from an aluminium billet and the internals created. Originally, cast iron sleeves were fitted to the cylinders, but these now run in a Nikasil coating and match the original pistons.
The 360-degree crankshaft turns backwards, with gear primary drive to reverse the direction from the final drive shaft and sprocket. Some of the clutch components were missing and had to be made. Inside the gearbox more mysteries were discovered. For Japanese domestic racing, only five gearbox ratios were permitted, but six were allowed in the Isle of Man. Consequently, this engine had five ratios with sixth gear removed. As fifth gear has a 1:1 ratio, the sixth gear has been recreated as an overdrive to present the power unit exactly as it was in the 1959 TT.
The engine is such a tight fit in the frame the valve covers must be removed before it can be installed. The crankcases are magnesium while heads and barrels are in pressure die-cast aluminium alloy. Magnesium is also used for both hub castings. To produce the fairing, Sebastian made up a wire jig which was then used to shape the aluminium. The original fairings were built in sections and had small gussets, screwed into place, near the hand shrouds to prevent cracking on this tight bend, and these have been recreated as original. Luckily, Mike Buttinger located a box containing the original seat fabric, which already had a pattern burnt into it. It was an intricate task but eventually the cover, which has a raised profile and is not flat, was persuaded to fit perfectly.
From a very long list, the largest single item to be produced was the frame itself, and fortunately measurements were able to be taken from the RC142 recreated by Honda. The colour is a unique blue and it took Sebastian eight attempts to come up with a perfect match. Exhaust pipes and megaphones will be finished in chrome as original. The restrictions of the past two years, including COVID lockdowns in the Netherlands, have delayed the final touches to the RC142, but once things return to normal, expect to see this remarkable restoration on display in the Netherlands and hopefully the re-instated Isle of Man TT.