Belt Slipping: Cause and Cure

Belt slipping is what happens when the belt moves out of sync with the treadmill motor and rollers. This can happen when:

1. The treadmill belt loses tension
2. The drive belt connecting the motor to the rollers wears out
3. There's a build-up of dust and friction over time

Left unchecked, slippage can make the motion of your running belt jagged and uncomfortable, or even create a safety risk. Learning how to stay on top of it can improve your workout experience and extend the lifespan of your machine.

Treadmill Belts: Behind the Scenes

A treadmill belt is the surface that carries your steps during a treadmill workout, but behind the scenes, it relies on several key parts working together.

The treadmill motor powers the front roller, which pulls the treadmill belt across the deck. The rear roller keeps the belt aligned and tensioned, while low-friction surfaces and lubrication help it glide smoothly.

If the belt is too loose, it can slip. If it's too tight, it puts strain on the motor and rollers. In a well-maintained home treadmill, the belt, rollers and motor all operate in balance for smooth and consistent performance.

• Motor: Supplies power to move the system.
• Drive Belt: Transfers power from the motor to the front roller.
• Front Roller: Pulls the running belt forward.
• Running Belt: The surface you walk or run on.
• Rear Roller: Keeps tension and alignment steady.
• Deck & Lubrication: Provides a smooth base and reduces friction.

Signs of Slippage

While not all treadmill issues are easy to notice at first, there are some key warning signs of a slipping treadmill that you can look out for.

• Uneven Speed: The console shows a steady pace, but your feet feel the belt speeding up or slowing down unexpectedly.
• Jerking Motion: The treadmill feels like it's pulling forward and back instead of gliding smoothly.
• Slipping Sound: A faint squeak, grinding noise or rubbing sound coming from the treadmill belt or rollers.
• Burning Smell: Excessive friction from a loose or dry belt may create an odour, signalling that the deck and belt are wearing down.

Belt Maintenance

Regular Lubrication

Lubrication is one of the most important steps in keeping your treadmill belt in good condition. Without it, friction builds up between the treadmill belt and the deck, causing the motor to work harder and increasing the risk of slippage. Most home treadmill models will need lubrication every 2-3 months depending on usage.

A silicone-based treadmill lubricant is usually recommended but always check your manufacturer's guide to see what's best for your treadmill. Apply the lubricant evenly beneath the treadmill belt to create a smooth, low-friction layer.

Click here to see our video guide on applying a treadmill lubricant.

Keep it Clean and Tight

Over time, dirt, dust and sweat collects on your treadmill belt and deck. This creates extra layers of friction, wearing down the surface and increasing the risk of slipping. It's good to build a habit of wiping down the treadmill belt after each workout and vacuuming around your machine to keep the track clear.

Tightening

Another step is making sure the treadmill belt isn't too tight or too loose.

Most treadmills have adjustment bolts at the rear. Turning them evenly on both sides helps restore proper tension and keep the belt centred.

Troubleshooting

Adjust Belt Tension

A loose treadmill belt is the most common cause of slipping. Use the adjustment bolts at the back of the treadmill to gradually tighten the belt. Turn both sides evenly, about a quarter-turn at a time, until the belt feels snug but still moves freely. A properly tensioned belt should lift about 5-7 cm from the deck when pulled up at the centre.

Drive Belt Inspection

The drive belt connects the treadmill motor to the front roller, transferring power to move the running belt. Inspect it regularly for signs of damage and replace it if needed.

Roller Tube Alignment

Misaligned rollers can cause the treadmill belt to drift to one side or slip out of place. Use the adjustment screws to align the rollers so the belt runs straight down the centre of the deck.

When To Replace

Wear and Tear

Fraying edges, cracks or thinning spots are clear warnings that the belt is due to be replaced. If the surface feels slippery or shiny, it means the belt has worn smooth and is no longer gripping the deck properly.

Refer to Manufacturer's Guide

Each treadmill model is different. Always check the manufacturer's guide to buy treadmill replacement parts that are compatible with your unit. The guide will also outline recommended replacement intervals and provide specifications for proper installation.

Belt Slip Prevention

Routine Maintenance

A consistent maintenance routine is the simplest way to prevent belt slippage. This includes regular lubrication, cleaning the treadmill belt and deck, and checking belt tension every few weeks. Small, proactive steps go a long way in reducing friction and avoiding wear.

Treadmill Mat

Placing your treadmill on a high-quality treadmill mat helps minimise dust and debris buildup underneath the machine. It also reduces vibrations, which can loosen parts over time and contribute to misalignment or belt slippage. For portable treadmills for home, a mat provides extra stability on hard floors, keeping the machine steady and the belt running true.

Reach Out if You Have Any Questions

Our team is always here to answer any questions you may about your machine. We're here to make sure you can get on with your workout without interruption.

You can also check out our other guides on treadmill maintenance and our guide to looking after your treadmill belt.