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THUNDERBIKE How a 1980s Sportster time- warped to the 1930s to win one of 2012’s top awards, no paint required
THUNDERBIKE How a 1980s Sportster timewarped to the 1930s to win one of 2012’s top custom-bike awards, no paint required…
By Buck Manning
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world class customs
GERMANY
Over the past nine years, the AMD Worl Championships of Custom Bike Building has produced a steady stream of interesting winners – not the dreaded themebike chopperfest many of us expected. A perfect example is the jaw-dropping 2012 Freestyle Class winner built by German Harley-Davidson dealer Thunderbike.
n It may have started out as one of the last Ironhead motors but by the time the crew at Thunderbike Customs was done, it looked like something from an old Brough Superior catalog. Brass and copper only add to the effect.
Thunderbike. Andreas Bergerforth, Thunderbike’s owner and custom visionary, had previously scored a second and a fifth at AMD’s Sturgis show, and he and his crew were resolved to accept nothing less than first place on this last shot. The 1930s Bonneville racer-inspired result, dubbed “PainTTless” for its almost total lack of paint, should be called “Flawless” for its total lack of imperfections.
What you’re looking at is actually the second iteration, as Andreas didn’t like how the 1984 Ironhead Sportster motor’s dimensions constrained the lines of his first frame. “The transmission made it look too flat so we started over,” he said. Starting over involved cutting off the unitized transmission and replacing it with a 1942 Harley WLA gearbox that was mounted up and behind the engine, not unlike the stacked units in today’s four-cylinder literbikes. With the engine cradle now running tight around the crankcases, the exhaust could exit behind the engine and below the swingarm like Andreas wanted. The 1000cc Ironhead had a second rear cylinder fitted up front and rotated 180 degrees so twin Amal Monoblocs could be squeezed between the jugs. This involved machining new oil passages and a whole lot more, while the rocker boxes were cut, split and tastefully reshaped. An eBayacquired 1928 Bosch magneto was
adapted, this time with more machining than you could shake a Haas CNC machine at. Other one-off machined pieces include the pushrod tubes, engine covers and hand-shifter setup.
Everything you see is fabricated and every piece dictated what the next piece had to be or do. Andreas wanted the gorgeous underseat finned oil tank/tailsection to appear to float in the air on its way aft. To do this and make room for a rear suspension and linkage, he had to devise a unique mechanism involving rocker arms and side-mounted horizontal shocks. The space needed for all this suspension movement gave the oil tank its whimsical shape. Front suspension is what Andreas refers to as a combination of springer and telescopic fork. Suffice to say that it works well and has a look like no other, but that’s not a surprise here.
The piece de resistance has to be those absolutely mind-blowing wheels. Carved from solid aluminum blanks, what appears to be the earliest set of drum-braked mag wheels ever are not quite what they suggest. Under all that intricate machine work are covered rotors, and if you look closely you can see Honda calipers that have become one with the finned drums’ backing plates. Thunderbike’s CNC machine must have been running for days to accomplish all of this stunning trickery. The tall-sidewall 19-inch tires, an Avon ribbed front and Heidenau block-tread rear, com
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n The man-hours involved in creating just the items shown in this close-up must be staggering. Thunderbike is a fullservice Harley-Davidson dealership, but the shop has built more than 160 customs to date, none more involved than PainTTless. No German build had won the top prize at AMD before, nor had a franchised dealer.
plete the vintage illusion.
The aluminum fuel tank was formed on a wooden buck and had to be metal-finished to beyond perfection if it was truly going to remain paintless. Juxtaposing the tank’s faultless sheetmetal is the delicate and beautiful mechanical complication of the brass gas cap and front mounting bracket, and just ahead of that the spinner-like steering stem nut. The view from the seat has to so hypnotizing that it could cause safety problems for riders! Then there’s the fairing that looks like it was formed by the wind while the aluminum was still molten. From the side, you can see that the airflow must get aroused just rushing over these silken shapes – or maybe that’s just the way I feel looking at them. Either way, they’re beautiful bodies in motion, even at rest.
Though there’s only a small amount of paint and graphics by Ingo Kruse, what there is only enhances the metallic finishes. The warmth of the copper and brass keeps things from being boringly monotone while the faux cast-metal finish on the wheels imparts an ancient and edgy feel at the same time. I just love this bike.
Andreas says this was his last AMD showbike, but with the show’s move from Sturgis to Essen, Germany for 2013 putting the contest only 33 miles from his shop, I think he’ll have a hard time not defending his title in his own backyard. You can check in on his website (www. thunderbike.de) to see if he can resist the temptation to compete. The only question is, what does he do for an encore?
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