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FIRST LOOK QUESTION: What do you call a Pro Mod or Funnybike rider who has tire spin and has to lift before he shifts into high gear? ANSWER: A guy who will be spending the next 90 minutes changing shift forks.. that's what. An automatic transmission is one of the things that you need when you go really fast. We are not talking about the torque converter coupled slush box in your mom's Lincoln Towne Car, we're talking about a real race transmission which requires no between gear ignition kill... one that picks most racers up an extra two tenth-second performance advantage for about $3500. Most of the transmission gurus have taken a stock transmission design and reworked it. Anytime you let off the throttle before you are in high gear, you bend forks and half the time... you snap some really expensive gears into little pieces. Companies such as Orient Express, Fast By Gast, MRE and R&D Transmissions, have found ways to make the transmissions live, longer that is, but sooner or later you'll be bitten and it's always at the wrong time. The stock parts are simply too weak. As horsepower increased, the solution became to reduce the number of gears, and widen the remaining number. They went from five to four speeds, then to three, and even flirting with two. The whole time, nobody got away from the stock design. Though they had the right idea about wider gear load distribution, nobody ever got away from a redesigned stock component. One company did, KLS, however they quickly went out of business... leaving just a few units behind... and in high demand and without any replacement parts. After banging his head against the trailer wall too many times, Team Kawasaki rider Steve Rice began looking for a solution. While looking for a company simply to make some replacement parts that would last longer, he ran across Weismann Transmissions - a manufacturer who made transmissions for Indy Cars, Forumula One, Offshore Powerboat, and other forms of extreme endurance powersports. Rice explaining his dilemma to Pete Weismann, a second generation gearbox specialist who had over 30 years in the field. Both examined what was being used currently, and looked for ways to improve it. The first problem point would be the shift forks -- so they opted to get rid of them. Looking at the gears, bearings and shafts, Weismann noted that they were good enough for a stock bike, but the dimensions and metals used would never stand up to the forces that a 500 horsepower dragbike, with a 12" tire, could dish out. They finally decided to start with a blank piece of paper. What they came up with was a three speed transmission, using an externally shifted gear cluster which used no shift forks. A pushrod ran through the inside the output shaft, attaching slider rings which engaged and disengaged the gears, to an external air ram mechanism -- mounted on the outboard bearing support. With this design, you could let off the throttle in any gear, and get right back into it again. No parts failure, no bending, no lost races. After months of blueprint drawing, CNC-programming, machining and heat treating, the prototype was born. It was made of metal which Superman could not bend. It's input and output shafts could transmit the torque from a submarine engine. After one single run down the race track, Rice knew that he had something that would change the sport forever. In just a couple of short years, Weismann produced a few handfuls of transmissions, that would enable racers such as Rice, Terry Kizer, Steve Suter and Jerry Graves, to power themselves into warp speed setting performances. Through it all, they only saw one major parts failure, a record that no other manufacturer could tout. Though it was bullet proof, racers hated the shifter button it used. It was a multi-button rocker switch design, which required the rider to concentrate on which button he pushed, and which direction he pushed it. Also, since it was only a three speed, you had to put forth every ounce of horsepower possible, otherwise it would bog slightly between gears (because of the wide spread of the gear ratios) and you would kill a couple of tenths off your elapsed time. About four years later, Pete's son (Chris Weisman) has come up with something even better. The Traction Products ZX-4 transmission features a similar design, using an external shifter, but now with four gears.
"With the addition of a fourth gear, the other three had to be narrowed slightly." explained Steve Rice, "but since the three speed was probably 40% overkill in the gear department, the estimated 10% loss in strength will go unnoticed."
For the tech types in the crowd, a stronger impact-resistant metal (possibly kryptonite, from another planet?) would allow an improved gear tooth design to be used. The shafts were made with the largest possible diameters and used fine tooth splines. The conventional ball bearings were replaced with super-tough caged needle bearings. All of the changes were in an effort to more evenly distribute the load that a dragbike can put forth.
Right now, the transmission is being produced for the water cooled Kawasaki ZX-11 engine. In the next few weeks however, Weismann expects to begin production on a "KZ" unit. At this time, orders are being taken for both models. For further information, contact: Weismann Transmissions Be sure to tell them that you saw it on DRAGBIKE.COM!!! |
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They have also fixed the unconventional
multi-button shifter with an electronically controlled, single push button unit. All of
it's components, the logic board, shift solenoids and plumbing, are condensed into a
compact and rugged billet enclosure. 
