XTreme XRs

Once fired up, you'd better get a grip. Think of a stump-pulling torquey, pit bull tough, light as a butterfly/sting like a million bees bike and you've got the gut feeling of riding an XR. Only one-quarter turn on the throttle goes from nada to WFO and it pulls without letup from 2000 rpm on up the scale and off it. While there's a rear disk brake, riders usually relied on engine compression to bring the bike down to non-warp speeds.

It should be noted the initial design for the XR750 is credited to a Dutchman by the name of Pieter Zylstra, and the first factory bikes tended to overheat, earning the less than favorable moniker as the "Waffle Iron." It was the legendary Cal Rayborn who brought the XR its first fame. Riding a Walt Faulk prepped bike, he won three out of the six British-American "Transatlantic" races. Think of a stump-pulling torquey, pit bull tough, light as a butterfly/sting like a million bees bike and you've got the gut feeling of riding an XR.Not content with mere roadracing, Cal piloted an XLR-engined streamliner to a land speed record of 265 mph at Bonneville. Sadly, Cal died in a 1974 crash aboard a Suzuki at age 33. Later Team Obsolete would campaign Cal's XR750.

Mert Lawwill rode more than one XR750. His 1974 Harley-Davidson XR750, owned by Carl Fronk of Langhorne, Pennsylvania, resides in the Motorcycle Hall of Fame Museum at AMA headquarters in Pickerington, Ohio. This XR750 featured Axtell heads, Lawwill's own special-grind cams and his chassis design. The same bike would be later campaigned by Mike Kidd, a member of the Kenny Roberts/Mert Lawwill racing team that was fielding a Yamaha dirt-tracker. Often aboard the venerable XR, Kidd edged out Gary Scott by just 5 points--200 to 195--to take the Grand National Championship. In other words, a bike that won the National Championship twice for its riders. Both Lawwill and Kidd were inducted in the AMA Hall of Fame and the bike is there for all to see.

XR1000 1983-4: A Factory Built Streetable XR

When riders first saw the XR1000 at the dealers, the level of enthusiasm was not as high as hoped for by the Motor Co. Some people whined about getting their legs around the protruding carbs and huge air filters. Others thought they were too expensive. Some said with only a 2.5 gallon gas tank how far could you get with a thirsty bike. The XR1000 was in production only for two years, 1983 and 1984. All the naysayers aside, today the XR1000 is now up on the pedestal as a collector piece.

No problem. I got the hang of it after the first two or three hundred times.

Mike Bowen's Pitbull Streetster: An XR with Teeth

If you saw "Kill Bill" you've seen Mike Bowen in action on the silver screen. He played "Buck" the lecherous hospital attendant "servicing" the injured Uma Thurman and ends up with his head used as a doorstopper. The half-brother of actors Richard and Keith Carradine, Mike's been in something like 50 films including Godfather III and on TV shows like CSI, X-Files and ER. When not pursuing his busy film career, he jumps on one of his bikes and blasts some of the "hollywood hype" out of his system. His bikes tend to be on the putbull side of things, loud, snarly and full of fight. Case in point his street legal XR750 flat-tracker.

His first XR was acquired from go-fast specialist Steve Storz, and says Mike, "Like my mini-Honda, I managed to blow-it to pieces. I delivered the basket case of shrapnel to Bobby who managed to rebuild the motor." The second XR project was turned over the legendary Mert Lawwill for a complete motor make-over. "I told him that I tend to get a little excited when I ride, so I wanted a motor that would hold together. As a result we decided to throttle back and go mellow rather than max."

"Like my mini-Honda, I managed to blow-it to pieces. I delivered the basket case of shrapnel to Bobby who managed to rebuild the motor."

Not only can you hear the XR a mile away, you can also smell the street legal flat track racer at some distance since Mike swears by Castor Bean oil, straight 40W, because it's "the only oil that goes toward the heat." He changes it every 600 miles, not because it breaks down, but because it suspends particles so well. "Any way, you want those particles removed frequently since the XR has no integral oil filter." It also feeds on 105 octane race gas, a liquid diet pretty much required by the 11.7:1 compression.

The resulting rebuild produced a 750cc Milwaukee mauler that was owner-friendly as in somewhat under-stressed, yet still thrashed out a stout 88 horsepower. Fed by a pair of 38mm Del'Orto pumper carbs, this non-kick starter equipped XR requires a bump start. Fortunately, Mike, also a boxer, has excellent stamina. Mike also lives on a hill which helps, although Mike says, "You don't need a hill, just roll the bike back just past compression on one cylinder, at which point it'll turn over, then the momentum will carry it through a revolution at which time it will pop into life. No problem. I got the hang of it after the first two or three hundred times."

"The bike rides like the Bullet train on rails..."

Tipping the scales at a mere 335 lb., handling is further improved by Works Performance shocks, a Champion swingarm, and Marzocchi forks. Sun rims are laced with stainless spokes from Buchanan's, the wheels shod with a pair of sticky race compound Avon Super Venoms. "The bike rides like the Bullet train on rails," says Mike. Why go with a race bike for the street in the first place, and have to deal with no starter, no lights? Mike answers, "A lot of people take a street bike, and turn it into a race bike. I think that's the wrong way home. I think you should start with a bare minimum bike and bolt on the bare minimum to make it street legal. My goals were to make it light weight with sharp handling, good torque, with serious mid-range and reasonable top end."

Painting chores, including the Jack Hagman aluminum gas tank, were handled by paintmeister Tony Marcus who sprays many of the L.A. area high-end exotic bikes while Montrose Auto and Boat upholstered the seat. The trick footpegs, mirrors, headlight mount, and brake caliper hanger were fabricated by Don Nowell Design. The headlight itself is a spotlight that once served duty on a police car, an extra added feature Mike thought appropriate. The excellent results of Mike's effort are clearly audible thanks to the SuperTrapp stainless exhaust system fitted with racing tips. Lightweight, "sufficiently" powered and benefiting from "much improved handling", Mike's Pit Bull Harley is a major contender for baddest bike around. "I can give all those Angeles Highway Ducati riders a run for their money, especially on the tight and twisties," laughs Mike.

Flash and Crash: Evel Knievel's Death-Defying XR750

Evel was going to leave Mother Earth, forsaking two-wheels for a fifteen foot long Harley-powered... rocket ship... the Skycycle X-1. The date was U.S. Independence Day, July 4th, 1973. The X-1 (yes, there was an earlier Bell X-1 experimental rocket plane that set records) was supposed to blast off from a 300 ft. ramp set on one side of the canyon, reach a velocity of 350 mph in eight seconds (which it did!), and then land by parachute on the other side. At least that was the plan.

In any case, Evel, a daredevil but not a dunderhead by any means, chose to replace the H-D V-twin with a Thunderbolt II steam rocket engine that pumped out 500 lbs. of thrust. The X-1 was supposed to blast off from a 300 ft. ramp set on one side of the canyon, reach a velocity of 350 mph in eight seconds and then land by parachute on the other side. Unlike an internal combustion engine with a whole bunch of moving parts, and thus more chance for something to fail at the wrong time, the Thunderbolt II had only one moving part. Seemed a good idea. Evel's sponsors were Harley-Davidson and Olympia Beer (always a good combination). Supposedly the only water pure enough to run in the rocket engine was the same pure water used in the beer, but that could have been pure hype, showmanship should we say, something Evel was a genius at producing. He was good, real good. To make a long, rather short story, shorter, Evel, after strapping on his good luck red, white and blue "Color Me Lucky" helmet was literally shoehorned into the cramped cockpit of the Skycycle. After lengthy preparations, someone lit the fuse, and Evel was off in a big flurry of flame and steam. He made it, well, part of the way, then bailed out with his parachute. Some say the ejection was way premature, but Evel stayed long enough to take the intense g-forces, strong enough to break one of his hips which had been surgically pinned after previous mishaps.

It was said that after so many bone-crunching spills, and resultant operations involving metal pins, Evel couldn't get within a hundred feet of a magnet... while his very real magnetic personality brought thousands of spectators flocking to his stunts. He earned and maintained international recognition as the premier death-defying crazy man for more than twenty years. The upside was that all the considerable pain gained him a measure of financial reward, purportedly six million dollars from the Snake River quasi-jump alone. (One of Evel's more widely witnessed accidents occurred on December 31, 1967 at one of Evel's nationally publicized events, a 150 foot fly-over of the Caesar's Palace fountains in Las Vegas. He cleared the fountains, but crashed hard upon landing, breaking his pelvis and a leg, but still went ahead with the Snake Canyon plans.)

Before Evel was riding rockets, he had a long association with land-bound Harley-Davidsons.

Towards the end of 1970, Evel signed a deal with H-D to ride the then-new XR750 Sportster in all his two-wheeled acrobatic displays of skill and "way-outness." Prior to this arrangement, Evel was already riding Harleys when jumping over cars and buses (lion cages, etc.), at least ten of them or a distance of 120 feet. Audiences, really waiting for him to splatter himself, ate it up. In June 1971, Evel was semi-immortalized by George Hamilton's portrayal of him in a film entitled "Evel Knievel," what else. It was pretty realistic except Evel never had as good a tan as Hamilton.

Evel transported his bikes in a very luxurious trailer-tractor rig complete with mahogany paneling and a whirlpool bath (and all of Elvis' big hits on the tape deck). He usually had three bikes set up for one stunt event; one for warm-up wheelies, another to show, the last to jump. The jump bike used a beefed up frame and rear section, and of course, a breathed-on engine. Wrenching on the chassis, race-tuning and such nuts and bolt work were not in EveI's job description: he was primarily an artist of speed and flight. While sensing every nuance of sound and feel of his bikes, he made certain that all components were coached to perfection since his life literally depended on it. This task he left to his chief tuner Roger Reimer, and when in California to experts like Steve Brackett.

"In the stunt riding business, you have to make up your mind that you'll have to risk your life to get on top; and when you get there, you have to keep risking it to stay there." And he did.

Harley-Hybrid 1200 Sportster

SoCal resident Steven Sites is a fan of the XR, dirt-tracking and the allure of transplanting the look of full-blown racer to the streets so he conjured up his personal vision based around a very modified 1200 Sportster motor and all the goodies he could find and then some. Can anyone out there in MO-land i.d. the source of the frontend? A clue... it's not from Milwaukee. Hint: we did say hybrid. Built some ten years ago, this feast for the eyes and soul is still food for thought for others similarly caught up in the magic of the XR.

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Here are a few words from a rider who has known the XR since about day one.

Been There, Done That on an XR:

By Steve Matz --Here are a few words from a rider who has known the XR since about day one. Steve also graciously provided some of the photos for this article as well as the production numbers for the XR. Says Steve, "I had the very first alloy XR that came to Montana back then. The initial Dealer Cost for the XR was $ 2395.00 which the Dealer let me have at that Price. I sold the Bike to a Fellow that used it in a Joey Chitwood Type Thrill Show and used it to Jump Cars (like Knievel) As of a few years ago he was still using the same 72 XR in his Shows." "In the stunt riding business, you have to make up your mind that you'll have to risk your life to get on top; and when you get there, you have to keep risking it to stay there." - Evel

"Actually my affiliation with HD Racing bikes precedes both the Iron & Alloy XR. I had 2 KR Racers which were the 750 sidevalve twins used in AMA Racing from 1954-1969 I always tried to stay in touch over the years even when I wasn't attending races as to the changes and continuing R&D of the XR through the decades. Its longevity in AMA Racing (going on 32 years) far exceeds any other HD race bike ever built in HD's racing history."

"The motorcycle which produced in the area of 70hp in 1972 is now Producing in the Area of 105 rwhp on Grand National caliber race engines. The engine is still basically the same as what came on the scene in 72. It has received mods such as CDI Ignition, dual sparkplug heads, 12-1 CR, titanium valves, cam development, etc. that has made it possible to produce the current HP figures but the engines reliability has suffered as 21st century HP is still trying to be extracted from a 30+ year old design that wasn't intended to have the extreme limits of engine endurance it has to be subjected to. The XR is probably living on borrowed time as far as future sanctioned dirttrack racing goes but it is still the motorcycle that most of the fans in the grand stands come to see. Although noise standards at race tracks have made it a quieter machine than the old open megaphone racers from the 70's and early 80's, its sound is still distinctive XR."

"Jerry Branch of Long Beach, Ca (Branch Flowmetrics) ported and assembled all the alloy XR Heads and also the XR1000 street machine heads which were essentially the racing XR750 head. After his shop did the polishing and porting, assembly, etc., the Heads were air freighted back to Milwaukee and the Racing Dept. did final assembly of the engines."

"One thing that is noteworthy. The H-D engineers told Jerry to port the heads to specs they had come up with during R & D. Meanwhile Jerry had been doing his own testing and flowing of the head and actually had a configuration that was showing 3+ hp on the dyno more than the H-D configured design. Jerry offered to port the heads using his design for the same contract deal as the original. But the H-D people said, no, port them to our specs which he reluctantly did."

"Now when you got your XR and wanted more power you had to ship the heads back to Jerry and pay a few hundred dollars for a revised port job that could have been free in your original XR if H-D had swallowed their ego and went with the better ports that Jerry offered."

"Branch's XR engines consistently put out more power than the best factory race engines. Jerry was also the first to extract 100 hp from the XR engine even before the factory did. His rider Hank Scott, who won many Mile track Nationals on Jerry's equipment, had noticeable HP advantage over HD's factory engines. Branch could have also probably got the now defunct VR 1000 competitive in AMA Superbike Racing but again H-D engineer's ego got in the way and the project was withdrawn from Racing after humiliating results."

Steve Matz-BSP