Treadmill powertrains – is your treadmill’s drive system sufficiently powered?
Walking on a treadmill places far more strain on a motor than running on it. When running, you’re actually kicking the belt backwards and are in the air part of the time. When you’re walking at 1 – 2 mph the belt is pushing your entire body weight while overcoming friction between the belt and the deck.
Exercise treadmills are built with motors designed for peak torque performance when running at much higher RPMs than you’ll see while walking, usually the top speed of the treadmill (10-15 mph, generally). At slow walking speeds the motors often lack the necessary torque (the force to actually turn the belt rollers).Don’t be fooled by the horsepower rating of the motor. In fact, you can ignore a lot of what treadmill advice websites have to say about motors. They’ll always tell you to buy more horsepower because they are generally speaking to an audience of runners, not working walkers. All things remaining equal more horsepower is better but none of those treadmills are designed to produce their highest torque at 1 – 2 mph.
What happens if the motor doesn’t produce enough torque? The first thing you’ll notice is very discomforting hesitation (“pulsing”) when your foot comes down on the belt. Most people can’t stand this. If you frequently lubricate your deck and belt you may be able to reduce or even eliminate this hesitation, but most people tend to rarely, if ever, take on the messy job of lubricating their treadmills. See our comprehensive guide to lubricating a treadmill to learn about the best and easiest methods.
Another thing that can cause belt hesitation is when manufacturers skimp on the weight and diameter of the flywheel that is attached to the motor. A strong flywheel takes more space under the cover and increases shipping costs. The function of the flywheel is to moderate the effects of stepping on and off the belt. Because the flywheel sizing is hard to determine off a spec sheet you’d be very wise to never buy a treadmill sight unseen. ALWAYS take it for a test walk before plunking down your cash. Even though you won’t be using it for running it’s not a bad idea to take a run on it just to get a sense for how strong and vibration resistant the frame is.
Far more serious and insidious than belt hesitation, however, is suddenly discovering that your motor or controller board has failed within the first few months, if not weeks. You will usually have no warning when in the middle of your work session the treadmill comes to a very abrupt halt, possibly throwing you. Sometimes this will be accompanied by a loud popping noise from a fried capacitor that had to deliver too much power to the motor. If the unit is out of warranty you’ll be better off buying a new treadmill.
Because 99% of the treadmills on Craigslist and in people’s garage are not appropriately motorized for the slow walking application you should be prepared for this eventually. It is a very good argument for buying an inexpensive new unit with at least a three year warranty on the motor and electronics. Make sure you get written verification from the manufacturer or seller that they will honor the warranty even if you use the treadmill just for slow walking.
When it comes to real enterprise-class office treadmills like the iMovR ThermoTread GT Office Treadmill you’ll find that peak torque performance is at the top design speed of the treadmill AND that the motors are very high-powered (3.0 HP is an appropriate size). The top speed of a real office treadmill will never exceed the maximum speed for NEAT heart rate, usually 2.0 or 2.5 mph. The bonus for capping the top speed at no more than 2.5 mph is to alleviate any legal liability concerns that some employers may have.