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Take a BrakeThe Sled Stops Hereby PennyJo Wagner There are a host of new brakes on the market, ranging from 2-by-4 wood block to stop a soap box derby to carbon fiber brakes found on Formula I race cars. With everything imaginable in between, it can be very confusing to the consumer. Northern Lites auto racing background has led to an understanding of brake technology and a need for a new, lighter and more efficient brake in the snowmobile industry. To understand what to look for in a good brake system, first you have to have a basic knowledge of the principles involved. Here are a few: * Heat diffusivity: Thermal dissipation (the ability to get rid of heat and run cool) is very important. * Weight reduction/rotating weight: The disc assembly is the most important place to remove weight. You will feel it on the throttle end, as it is less weight for the motor to rotate. * Rust resistance: Resistance to rust is a big concern in the snowmobile industry. * Consistency: Ask yourself, does the brake always work with the same effectiveness? Does it have to "come up to speed" for proper heat, or does it lose some of its effectiveness when it gets hot. You want your brakes to perform and feel the same, every time. * Fade: Another important factor with brakes is that the material does not fade when wet. Auto racing has taught us we want our brakes (disc) to be able to get rid of the heat. We don't want too much heat because heat is passed to the piston in the caliper. The piston can only take so much heat. Then the heat transfers to the brake fluid. A common term used with brakes is hydroscopic, which means brake fluid absorbs moisture from air. Water is heavier than brake fluid. This moisture ends up in the piston. Water boils at 212 degrees. Quality brake fluid boils at 446 degrees. But when contaminated by water, it will boil at 311 degrees, diminishing the effectiveness of brake fluid. When the water boils it can cause the brake to be spongy. Because of the potential for this problem to arise, race teams change the brake fluid after each event. Good teams will bleed the system after each practice. Steel Working Steel is the material used for brake rotors on most stock snowmobiles. Some have drilled holes in the steel rotors in an effort to reduce weight. Stamped steel is heavy and subject to rusting. Then there's stainless steel, which is homogeneous material. Being so uniform causes it to be slippery which means the friction pads can slip. Although stainless steel is a great material for resisting rust, it doesn't dissipate heat well. When it gets hot it stays hot, making it subject to warp. Aluminum does not make a good brake rotor. It is super in the lightweight department, but it is also subject to "smear," which means when the rotor gets hot the material actually gives way under the pressure of the braking pad. It has been used in mountain biking, but even then it is marginal. And that's on a 30-pound bike, which doesn't travel near the speed snowmobiles do. Some forms of auto racing have used aluminum rotors, greasing them to get through an event. Monster trucks use six brake rotors -- one on each wheel and one on each drive planetary (axle) where the drive line hooks up. Titanium and carbon fiber are the newest "buzz" words in snowmobiling. The properties of titanium are not nearly as good as aluminum or NL2 material. Titanium is 45 percent lighter than steel; however, it is 22 percent heavier than NL2 metal. Titanium is stronger than steel, aluminum, or NL2 metal, but the need for a strength to weight ratio is not a problem in a brake rotor. Carbon fiber is being used in the ultimate of race cars, Formula I. Carbon fiber is the lightest of all the materials being used in braking applications. It is very susceptible to cracking when scratched. In the brake rotor environment, the rotor must be brought up to a very high temperature for carbon fiber to be effective. Some FI racers are driving with one foot on the brake with a bit of pressure, to keep the carbon fiber rotors up to heat. NL2 is Cool NL2 was specifically formulated for brake rotors and has proven to be an excellent material for this application. It is 66 percent lighter than steel and has a higher co-efficient of friction than steel. Unlike steel, NL2 doesn't fade when wet, rust or crack. It has reduced brake noise and less vibration. NL2 runs the coolest of the materials being used for brake rotors. It works well consistently, whether hot or cold. The hub is also important. The stock hub is of steel (powdered metal) and very heavy. Keep in mind that this is also rotating weight. An aluminum hub weighs much less, but be sure of the type of aluminum that is used in manufacture. A hub of 6061 may not be strong enough, allowing the broaching rounding out. Heat treated 7075 is the light weight, but also has the strength to hold the load. Also consider the mounting hardware. Are you about to purchase a wonderful new hub and rotor, only to put it together with heavy, rusting nuts and bolts? Stainless steel or titanium hardware would be the best way to go. Please, ask before you purchase. Be sure you are getting the very best brake available for your snowmobile. Be sure to check out the Northern Lites, Inc. Brake Package! For More Information Contact: |
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