The motor is the heart of a treadmill. The main question for a treadmill buyer regarding motors is whether it is powerful enough for the intended use.
Generally, a more powerful treadmill motor will run more smoothly, carry a greater weight for a greater period of time, and will last longer than a weaker motor. However, it is usually not necessary for a treadmill buyer to conduct a detailed analysis of a treadmill's motor. This is because manufacturers choose different motors for different treadmills in coordination with the other components of the treadmill. Thus, for example, a treadmill with a long belt and a high user weight capacity will be fitted with a much more powerful motor than a treadmill with a short belt and low user weight capacity, because a more powerful motor is needed for the intended larger user. In the same way, a treadmill intended primarily for walking will have a motor that meets that requirement, whereas a serious runner’s treadmill will come with a motor that is made to withstand such use. A treadmill cannot be fitted with a motor different from the one it was made with.
Nonetheless, shoppers do like to understand what they are buying. The first point of confusion is the description of a motors horsepower. More horsepower means a more powerful treadmill. However, commentators confuse the issue by insisting the buyer look at "chp," or continuous duty horsepower, instead of "hp," or peak horsepower. Chp is how much power the motor can sustain during prolonged use, while hp is the maximum power the motor can generate. The problem arise when some manufacturers quote chp and others quote hp. At least one manufacturer has even stopped labeling chp as chp because people kept asking what it means. To make matters worse, there is no universal standard for measuring chp or hp. Thus, for example, one manufacturer's chp of 3.0 may be equivalent to another manufacturer's chp of 2.5. Some manufacturer's may label a motor "commercial" or "commercial grade," but there is no industry definition of that term.
Too small a motor will tend to overheat. But, again, the simple way to choose the right motor is to choose the right treadmill and let the manufacturer choose the motor. However, a good rule of thumb is that a runner will want a motor with a chp of at least 2.5. Heavier users will be better off with a bit stronger motor.
Another indication of treadmill motor quality is the length of its warranty. However, it appears treadmill manufacturers package their standard warranties with varying lengths on various components as part of their total offering based on market research as to which combinations sell best. Therefore, an isolated consideration of a motor's warranty would not be particularly meaningful. In any case, it is unlikely that a properly used motor will need replacing. If a part needs replacing or repair, it is far more likely to be the belt or electronics.
Virtually all home treadmills sold in the U.S. come with DC (direct current) motors, while the bigger, more expensive treadmills in gym have AC (alternating current) motors. DC motors start more slowly than AC motors, but tend to provide a more consistent response to changing demands than AC motors. Either kind of motor can be used in the standard wall outlets in the U.S., but users in much of the rest of the world will need an adaptor for their DC motor to work in their outlets.
DC motors use their full power only when running at top speed. Therefore, walking with them, instead of running, does not use their power efficiently. This is not ordinary a problem, except when a user weighs more than the user weight limit for the treadmill. The heavier user will put stress the motor, make it run hot, and possibly shorten its life. This is another reason why it is better to concentrate not on the motor, but on the user weight capacity and belt length. If the weight capacity and belt length are right, the motor should be also.
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