Why is this kid smiling? He's got one of the trickest mini race quads in the country!
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It's easy to find parents who say thier kids come first. Finding parents who really do it is another matter entirely. Here at ATV Action we can tell parents care when they make some effort to help thier children enjoy ATVing. They might take thier kids to a race or surprise them with an issue of a hight quality ATV magazine like ATV Action. Parents who make it possible for a youngster to have his or her own machine are real heroes.
Robb Leonard hand-made the machine's entire chassis in addition to modifying the Kawasaki KX60 dirt bike engine for quad racing. When you consider the skills and labor involved, it's an amazing accomplishment. The guy will probably have a manned mission to Mars completed before NASA. |
Underneath, Robbie's quad has a full length glide plate and the smooth bottom of the linkless swingarm to keep it from snagging on jumps or whoops.
Then, on a whole other level, there are dads like Robb Leonard, owner of Robb's Racing Engines (contact: [603] 231-1692). He got his son, Robbie a Honda TRX70 when he was two. At age four, Robbie entered his first ATV race. More racing and faster machines followed. By age six, young Robbie was racing a highly modified Honda TRX90 prepared by his dad. Currently, at age seven, Robbie is the defending champion of New England ATV MX (NEATVMX) series' 0-70cc stock and modified class. We interviewed Robb Leonard about the fire-breathing Kawasaki KX60 motocross motorcycle-powered quad that he built to help his son dominate mini ATV racing in New England.
ATV Action: What got you interested in building a mini race quad around the KX60 dirt bike engine?
Robb Leonard: Engines in existing mini ATV's are designed to be easy to use rather than for performance. In championship level mini ATV racing, electric starters and automatic transmissions aren't needed. The two-stroke, liquid-cooled, six-speed manual transmission KX60 has become a popular powerplant for the 0-70cc class because it's a high performance racing engine in stock form. It also responds well to modification.
ATV Action: How did you modify the Kawasaki dirt bike engine to make the power delivery better for a quad?
Robb Leonard: Small racing motorcycle two-stroke engines don't make any bottom end power at all, so I worked on creating some low-end and midrange power without sacrificing the strong top end pull the engine has to start with. To accelerate the extra weight of a quad, the engine needs more solid response, especially when exiting corners. Low-end and midrange power is important for clearing some types of jumps also.
ATV Action: What engine mods did it take to create that type of power?
Robb Leonard: I increase the bore to raise the displacement to a 69cc, modify the head, port the cylinder, change the reeds and add my own pipe and Pro Circuit silencer.
ATV Action: How did you go about making your own chassis for the engine? Just making everything fit is an accomplishment, but building a quad frame that handles is amazing.
Robb Leonard: As an ATV racer myself, I have a lot of experience with quads. I also used to build sprint cars, so I'm used to choosing the right materials, bending tubes and doing the welding.
ATV Action: What is the material?
Robb Leonard: Chromoly steel.
ATV Action: How did you determine what geometry and engine placement would work? A quad is a lot different than a sprint car in those areas.
Robb Leonard: I adapted a lot of design elements from a Lonestar Honda 250R chassis, but on the KX60 quad, everything is scaled down.
ATV Action: What is the approximate size of the machine, compared to existing quads our readers are familiar with?
Robb Leonard: It's like a 2/3-scale Honda 400EX.
ATV Action: Is the rear axle a standard part?
Robb Leonard: It's a Lonestar Honda 250R axle.
ATV Action: What shocks are you running?
Robb Leonard: Fully adjustable Works Performance shocks, with remote reservoirs. They bumped the tavel up to ten and an half inches, front and rear.
ATV Action: Are the A-arms or swingarms off-the-shelf items?
Robb Leonard: No, because of the special size of the quad, everything was hand made, including the A-arms and swingarm.
ATV Action: Don't tell us you made your own radiator?
Robb Leonard: No. It's from a Honda street bike, a VF700. I wanted to make sure the engine had more than enough cooling because it gets run pretty hard moving the quad.
ATV Action: The bodywork looks familiar.
Robb Leonard: It's a Maier Honda TRX 90 replacement bodywork.
ATV Action: How much time do you estimate you have in building this quad?
Robb Leonard: Hundreds of hours, but it's been worth it. Robbie enjoys it and his racing results on it speak for themselves.
ATV Action: Have you considered building and selling replicas of the machine?
Robb Leonard: I've already built and sold some. They cost from $12,000 to $14,000, depending on how they're equipped.
