Common sense suggests that something is out of the ordinary when you smell burning rubber coming from a machine. This is especially true with motorized treadmills. In most cases, the cause of the odor can be identified with an inspection. It's important to stop using the treadmill until you correct the source of the burning smell, or you risk permanent damage to certain parts or components.
Running Belt and Deck
The running belt and deck are the first consideration when you smell burning rubber. Treadmill belts are made from composite rubber and when a belt is not correctly aligned, it can ride against the frame at one side of the running deck. Subtle rubbing noises during a workout indicate the belt is out of alignment. If not addressed, the edges of the belt heat when in constant contact with the frame, producing a burning smell. Another cause of burning smells is excessively high friction between the underside of the belt and the running deck. This is the result of a lack of lubrication or periodic cleaning, as recommended by the manufacturer.
Rollers and Bearings
The running belt turns on rollers at the front and rear of the treadmill. A drive belt and a treadmill motor located below the front cover of the machine power the front roller. The rear roller serves as support for the rear of the running belt. Each roller has a set of bearings that support it on an axle. Dry or dirty bearings at the front roller make grinding noises that indicate it's time for servicing. Left unattended, a bearing can fail, causing the drive belt to perform erratically. If the running belt and deck are properly maintained and you continue to smell burning rubber, the problem is a roller bearing or the treadmill drive belt.
Drive Belt and Motor
You access the drive belt and treadmill motor by removing the cover at the front of the running deck with a screwdriver or a metric hex wrench. A close inspection of the drive belt tells you whether the belt is the cause of the burning smell. Look for fraying or dark patches on the edges of the belt that indicate it has been turning erratically on the motor pulley or the secondary pulley. If the belt appears undamaged, remove the motor and have it tested by a qualified technician. Although electric motors typically emit a different smell than burning rubber, a weak motor causes the drive belt to slip on the pulleys when you work out, which generates excessive heat.
Maintenance and Adjustments
Similar to all motorized machines, treadmills require a certain amount of attention to ensure optimum performance. Your treadmill owner's manual has information regarding periodic maintenance that is specifically tailored for this purpose. Typical procedures include cleaning dust and debris from the undercarriage, as well as the contacting surfaces of the running belt and the deck. Some running decks require a dry lubricant that is specified in the manual. Make a point of observing the alignment of the running belt on a regular basis and if necessary, adjust the alignment to center the belt on the deck.
Member Comments