Editor's note:Bikernet correspondent and Technical Editor of Australia’s Heavy Duty magazine, Doc Robinson, gives us the scoop on secret testing being carried out with Harley-Davidson’s new XR1200 in preparation for a world record jump:
Harley-Davidson’s XR1200 got off to a flying start down under with secret testing carried out in the Australian outback by motorcycling stunt legend Seth Enslow. Testing has occurred in north-western Victoria near the outback town of Mildura. In a dry and dusty setting with an onlooker gallery of kangaroos, emus and koala bears – plus a few hardy bush folk – an XR1200 was put through its jumping paces.
The most famous name associated with jumping a Harley-Davidson motorcycle is the late and great Evel Knievel, who in February 1971 set a new world record by jumping 19 cars with his Harley-Davidson XR-750. Evel held the record for 27 years until Bubba Blackwell jumped 20 cars in 1998, also on an XR-750.
Evel’s record distance was 151 feet (46m) and Bubba (the current holder) managed to jump 157 feet (47.8m), but now Seth Enslow, widely known through his role with the Crusty Demons of Dirt and his motorcycle distance jumping records, is out to set a new world record jump on a Harley-Davidson motorcycle, a brand new XR1200 with specially developed suspension.
Bikernet asked Seth how this attempt came about.
SE: “I’d say it came about because I’ve always liked Harleys and had Harleys for years and I just thought it would be good to revive the idea of jumping one. Since Evel Knievel, not too many people have jumped one and if they have, they haven’t really gone too far. I think that the new XR1200 is capable of going well over 200 feet with the right ramps and the right suspension on it. Yeah, I just want to do something different but kinda stay at my end of the sport instead of doing the competitions like the kids are doin’ nowadays.”
Bikernet: “When and where is the attempt going to be held?”
Seth: “It’s supposed to happen in the town of Red Rock just north of Las Vegas Nevada where the owner of Las Vegas Harley-Davidson wants the jump to be part of the official grand opening ceremony of the Red Rock Harley-Davidson store. We are scheduling it for somewhere around March, 2009.”
Bikernet: “You obviously approve of the XR?”
SE: “Yeah it’s got several features that make it suitable including a big strong aluminium swingarm which will be better for the different suspension that we need to use. Gavin Walker from Mildura’s Quick Fix Harley has already done a lot of work on the bike including extending the swingarm and setting it up for the necessary suspension changes that are required and using a revolutionary suspension system invented and produced in Australia. Of course, whether we do go with this suspension or revert to a customised, but more conventional, system depends upon further testing.”
Bikernet: “Now I believe you’ve had several practice jumps though not over any great distance yet. How do you think the XR will feel in the air once you get it a bit more sorted out?”
SE: “So far, so good though the gaps real small as we speak at around 70 or so feet but I hope to extend it later today when it cools off a bit. Are you going to be there?”
Bikernet: “You bet, wouldn’t miss it!”
SE: “You know, how we go tonight will depend on getting the suspension set up just right and as you know the boys are working on it right now. Once the suspension is set up so that it doesn’t feel too stiff but also won’t bottom out we’ll have a bit more of a go, start moving the ramp back and see how it flies. But to this point it is flying relatively level and straight.”
Bikernet: “Is there anything you’d like to add regarding the event in March?”
SE: “Sure. It looks like Monster energy drinks will be the title sponsor at this stage. They’re going to supply some riders too because on top of me breaking the world record for a Harley, there’s going to be Ryan Capes on his KX450 who hopes to smash the overall distance record on a motorcycle and he’s going to try for 400 feet on that, plus there’ll be BMX distance record attempts, skateboard distance record attempts and I’d like to do close to 200 feet myself on the Harley.”
Bikernet: “Good luck with the record attempt Seth.”
Later that day in the back-blocks of Mildura as the sun began to sink in the west, Seth performed a series of jumps, gradually extending the ramp until on the very edge of darkness Seth cleared a distance of 137 feet (41.7m) and pronounced the bike as very capable and that he was happy with the suspension at this stage.
Aussie Built Suspension
Even the briefest of glances at this XR reveals that it is not running stock suspension. In fact it is currently fitted with specialised forks and rear shockers, units built in western NSW by Ian Linklater of Boundless Suspensions Australia, who have developed a new shock absorber technology that they claim, “will revolutionise the way we look at suspension.”
Ian and Gavin Walker from Quick Fix Harley, worked together setting up the suspension for the XR by firstly lengthening the swing arm and setting it up with a number of shocker mounting points to allow experimentation during jumping trials.
Gavin briefly explains the technology. “Using nitrogen and a floating piston, the forks themselves contain no springs and consist of an inner and outer fork tube with fluid in the top of it and air inside the fork tube along with valving and the floating piston. With these custom forks the length allows for considerable travel which is necessary when jumping a heavy bike like the XR1200 which weighs in at a hefty 263kg (580lbs).
“That weight is quite a lot more than (say) Ryan Capes’ Kwaka which comes in at 112kg (246lbs). Naturally, the Boundless system allows for both compression and rebound adjustment. We’ve worked quite hard on getting this set up right for Seth on the XR1200 and so far we’re looking good with it. As we’ve been extending the jump lengths, it’s been coping well.
“However, whether this is the suspension which will be used in the record attempt or not, depends upon further testing and time constraints. We hope so though, because it will help put this Aussie invention on the world map.”
