An enduro experiment
ROKON was a little-known US manufacturer of unconventional off road two-wheel drive, fat tyred, automatic devices created for hunters and backwoodsmen to access rugged country.
In production since 1964, their ‘Trail-Breaker’ model got them noticed because of the sheer uniqueness of its design. ROKON motorcycles use a combination of belt, chain and shaft drives coupled to gear boxes to drive both the front and rear wheels. Older machines were powered by a Chrysler Marine 820 two-stroke engine (134cc), while newer machines have either a Honda or Kohler engine of about 6hp. Each hollow wheel can hold 2.5 gallons of fuel or water for long distance trips. The large tractor style tyres even enabled it to be floated across rivers. The fact that ROKON – based in New Hampshire – continues production of the models; TrailBreaker, Ranger and Scout today is remarkable. But that’s not where the story ends. How many of us standing around with friends have dreamed of creating the ultimate dirt bike?
Sure, modern bikes are that advanced they even talk to you, and we seem to have reached the ergonomic limit that Maico set in 1981. But, back in the 1970s we were wishing the future would hurry up and appear. The engineers’ dream of starting with a clean sheet of paper was often just that, but some dreamers were driven enough to give it a crack.
In ‘The true history of ROKON motorcycles’, author Bob Gallagher says, “In 1970 Nick Harris obtained majority control of the company and in May of 1971 embarked on a project to develop a motorcycle for that portion of the market ►
not dominated by the Japanese; a competitive enduro bike. The TR-340 was quickly developed and was successfully racing by September 1971 when it won the AMA-sanctioned event at Talledega, Alabama. The RT-340 was first in class, second overall, and the trophy was said to be bigger than the rider.” Tom Clark worked in the USA AMA and rode PUCH in off road, internationally too. He spectated at the Isle of Man, International Six Day Trial in 1971 with a prototype motorcycle. Developed with ROKON engineer Mike Hamilton, the bike was an aesthetic jumble of Yamaha tank and seat, SACHS 340cc snowmobile engine, scooter style CVT belt and pulley drive, pull start, beefy frame, conventional Betor suspension, KimTab mag wheels, rudimentary airbox and disc brakes.
This was thinking outside the box. You can imagine the difficulties the two designers would have had convincing an agricultural manufacturer to branch out into a whole new area with a revolutionary design. The only connection was the use of the SACHS 340 in their utility vehicles. While many a one-off sees the light of day, not many make it through to production. So was born the ROKON RT-340 TCR (Tom Clark Replica).
Bob Gallagher again, “In an internal ROKON document titled ‘RT-340 Preliminary Market Analysis’ from September 1971, ROKON saw a ‘one billion dollar market’ they intended to tap and noted, ‘The ROKON motorcycle (ie: the RT-340) must sell at a high enough price to ensure a 40 per cent gross margin; it must be price competitive, it must perform equal to or better than its own particular competition, and it must be capable of inspiring end users to request dealers to stock it’. Pretty lofty goals for a company that had no experience with traditional motorcycle production or sales.
“By late 1971, and no doubt spurred by a $260,000 net loss for the year, mainly attributable to RT-340 development costs, Nick Harris had lost interest in the company and controlling interest in ROKON was obtained by E.R. Hampson. Bob Grip was company president, rider Tom Clark was vice president and Orla Larsen was ROKON director. The short-term business objective became for ROKON to live within its own cash flow and return to a profitable operation. By the end of the first quarter of 1972, and with the help of 416 Trail-Breaker sales during the period, the Trail-Breaker was showing a profit, but a loss was incurred by the continuing RT-34- development and racing program. Targeted at the very top end of the enduro price range, the RT-340 program would bring ROKON to its knees.” First tested in 1973 by the US mags, the test riders approached the bike with caution. While impressed by the engineering you could tell from the writing, they were sceptical too. The mainstream magazines loved analysing the engineering concepts (rear brake pedal facing backwards, floating hydraulic disc brakes, reduction gearbox, etc) and quoting gearing specs. There was much trumpeting of how this Auto was the bike of the future, yet they saw it as more of a design exercise. The pull starting was unique (watch your knuckles on the underside of the fuel tank seam!) and care had to be exercised with not too much of a throttle opening initially. Riding was different, it was a heavy bike and throttle lag was an issue, as was the downhill freewheeling. The left field mags (well, it was the 1970s) lauded the concept. It was considered a breakout from the same old – same old designs year after year. The only detriment was the loud clatter and ringing from the cylinder and barely muffled exhaust pipe. This noise problem was addressed with the next model in 1974, the RT 340 I, with a quieter pipe and it also had a plastic tank with an option of spoked wheels and a white colour scheme. 1975 was a mishmash of previous parts. The 1976 Bi-Centennial model was the model’s last hurrah, the TR 340 II,
with long travel forks, new frame, laid forward shocks, new red/white/blue colour scheme, down pipe and plastics. In 1977 the ROKON RT340 II was advertised as the new GMR (Gold Medal Replica).
In competition, the RT340 surprised a lot of people. In the 1973 ISDT in Massachusetts all four entered finished, with three bronze and one silver medal. Since then, the bike has earned accolades for its capabilities in the ISDT and the tough New England events – mud, beaver dams and rock-strewn courses that kill ordinary bikes.
Local NETRA riders Jim Hollander, George Peck, Gary Edmond and Scott Wentworth proved the bikes’ viability in New England and the wider USA. In events from 1973 to 1976, ROKON won 55 Golds, 33 Silvers and 23 Bronze medals in US Two Day Enduro Qualifiers and ISDT competition.
ROKON also produced a motocross model based on the RT 340 II, surprisingly successful under sponsored rider Don Kudulski, winning races in the Florida Winter MX. Even more surprisingly, an RT340 scored short track wins with Joe Bonanno and Mickey Hill in 1977. But after that …
ROKON went into receivership in 1978 with some blaming the development costs of the RT340. The company was back on its feet in 1981, but just producing the Trail-Breakers.
Sadly, it took courage to run the ROKON flag up the pole, but not enough patriotism could carry the concept on when too few saluted the flag.
A local ROKON
This is the 1973 RT-340 that Don Stafford (then of BDG Enduro and Motocross Equipment) in Victoria brought into the country and was tested in AMCN (Oct 1973), Two Wheels (February 1974) and Trail ►
& Track (March 1974). Frame number RT340.782, Sachs motor SA340R #7486962 and ‘Sept 24, 73 FDC’ engraved on the rear of the Trans Reduction box, is the actual bike tested. How can we be sure? The vinyl seat cover has the same ‘fingerprint’ lines and small dent in the torque converter cover as photographed in the T&T test.
To say the bike was unusual would be understating it. Mag wheels 19” front and 18” rear, lawnmower style pull start, automatic twist and go and large disc brakes caused lots of comments. Testers of the day had a hard time getting their head around it. The ROKON designers (including enduro rider with ISDT experience Tom Clark and legend Dick Mann) started with a clean sheet of paper and created a futuristic motorcycle that challenged the conservative thinking of traditional dirt riders. It split riders, those committed to it who understood its peculiarities and the tyre kickers too ready to heap scorn on it. It wasn’t nimble, it didn’t snap to attention when wicked on, it felt heavy in the front, belt friction made it hard to push, you wheelstood and slid it at your peril as it didn’t shut off when you did, etc. But it was fast – able to out drag any motocross bike and while heavy, once under way it was surprisingly responsive to rider input and had a light touch to it, it found traction everywhere, the brakes worked, it would plow through anything as long as you kept some throttle on so water couldn’t get between the belt and the pulleys – but don’t anticipate getting the front up over a log as it’ll just plow into it. Funnily enough, very few events in the USA had log crossings in them from my scanning of magazines and experience riding in Canada. Riders had to stay a step ahead of it to factor in the response time lag but talented riders (like USA ISDT medalist Jim Hollander) used it as weapon to dominate the 350 class.
Back to Don Stafford and this bike he had airlifted out of the USA – with enough spares for five bikes. He let the journos and some A grade motocross riders (Karel Morlang for one) test it and of course everyone had to try to get the front wheel in the air. They quickly learnt about drive lag; it kept on driving after closing the throttle and looping it regularly. Credit is due to the Dick Mann frame, characterized by large diameter tubing, so no permanent damage was done. Don put in an order for 12 bikes and the deal was done until a late telex stating unfortunately ROKON had to fill and order for the US Army. By the time stock was available Don had cooled on the idea and cancelled the order. What happened to this bike next and the ongoing owners is unclear but the spares disappeared without a trace but the bike turned up, painted silver in a wreckers yard in bayside Melbourne. A friend alerted me to it so I went for a look. It was fairly complete, missing the original exhaust, guards, watch magnifier, taillight (funnily enough!) and route sheet roller. The mechanic worked his bicep at the pull start with a few coughs (the bike) and a few words (the mechanic) but flipping the crankcase drain spigot open cleared it out and it started with that familiar ‘blamp blamp blamp’. I got on and with a ‘bwooooah’ the thing took off. Listening to the engine noise I was fooled into thinking all was under control until coming up to a T intersection I realised I was going way too fast! Panic locked up the brakes and I just slid to a stop. Phew, deceptive! $750 changed hands and I loaded it up.
Now for the hard part. Getting it back to original. I got in touch with Hoskin’s in the USA who were ROKON dealers and found they had a stock of parts for the bike. First thing was the pipe. It had the
1974 version on it – not the rectangular one that was stock. They had one but had to cut it to shorten the package. Guards and other bits and pieces were ordered in two shifts, and I had most of the bits I needed bar the route roller. Two wins were the tank- I just used paint stripper and got rid of the silver and revealed the perfect yellow gelcoat underneath. The second was the seat stitching had rotted and I was reluctant to get it recovered but I found my upholsterer was able to re stitch the cover using the exact same needle holes. The rest of the bike went through the usual clean, scrub, strip, derust, re-chrome, paint etc., and the brakes that saved me were now all seized up. What a drama getting seals, unclogging the lines, finding pads (Honda 750/4) and so on. The engine top end I left as is as it made it less effort to start and it certainly wasn’t lacking in power.
Riding it was ‘good unusual’. Once it took off at about 2,000rpm, it flat-lined at 4,000 at maximum torque and just got faster. It likes to pull and so working the throttle on and off constantly kept it under control. It was the perfect vehicle for arrowing Vinduro courses which I was just getting into at the time, in the 1990s. Gas-it, brake, lean against a tree, staple marker, repeat. It’s certainly a crowd pleaser at events, pull starting it always draws a crowd. Especially if after a few yanks on the pull rope you get a bit sloppy with your throttle control and take off just as it fires up! Just watch your knuckles on the under-seam of the fiberglass tank! It’s sharp if you don’t miss it on the up pull. ■