1. Home
  2. /
  3. How to Center Treadmill Belt Properly?

How to Center Treadmill Belt Properly?

Last Updated on November 4, 2021 by Jeff

One of the most common problems people face with their treadmills is that the belt goes out of place with time, which shows when the belt starts rubbing against the machine’s side during operation.

How to Center Treadmill Belt


Proper maintenance is key to prolonging your treadmill’s life at a solid performance, and you need to know what you’re doing. But don’t worry, as it’s very easy to fix a misaligned belt, so follow along for the right way to center a treadmill belt.

What Makes a Treadmill Belt Derail?

Diagnosis is an essential part of solving a problem, so it’s important to know what makes treadmill belts derail in the first place.

There are three main reasons why treadmill belts go out of alignment:

  • The treadmill could’ve been placed on a floor that’s not leveled
  • The front and rear rollers under the belt could be out of alignment
  • Your belt could simply be too old and needs to be replaced

Once you notice the belt drifting aside, you need to act quickly before it starts folding over the side of the treadmill, which will damage the belt, and it could also destroy the machine entirely as its electronics will try to fight the resistance caused by the belt’s misalignment.

Safety is also very important. You don’t want to trip over while running at several miles an hour because the belt got stuck on the frame.

How to Center a Treadmill Belt in 3 Steps 

All you need to fix this problem is an Allen key that the treadmill’s rear roller bolts fit in, which is a standard tool in most garages anyway. Most bolts I’ve seen are three to six millimeters in diameter, but some can be as wide as 8 mm.

Step 1: Observe Where the Misalignment Is

center treadmill belt

Turn the treadmill on at the slowest setting it has and watch for the gaps between the belt’s ends and the rear roller. If the belt is misaligned and drifting towards a particular direction, then the gap will be smaller on that end, and vice versa. The gaps need to be as equal as you can make them.

Step 2: Adjust the Left Bolt treadmill bolts

Treadmill rollers have two bolts on the rear end. For adjusting the alignment, always use the left bolt as the right one is used to make other adjustments.

As a general rule of thumb, if the gap between the belt and the roller is smaller on the left, as in the belt is drifting to the left side, then you need to turn the left bolt clockwise to tighten the bolt. If the gap is smaller on the right, then turn the left bolt counterclockwise to loosen it.

Many people try tightening and loosening the bolt without reading about it first and end up giving it three or four turns, which is just overshooting it and will throw the misalignment to the other side.

Instead, you want to do it gradually and in increments of quarter turns or even half turns if the gap difference is too big. After every turn, wait about 10-20 seconds for it to take effect, and if the gap difference is still unequal, repeat the process until the alignment is good. Of course, it doesn’t have to be perfect, but get it as centered as you can.

You can amp up the speed to 10-15 mph and give it a minute to ensure the belt stays in the center at higher speeds.

Step 3: Test the Tension how to center nordictrack treadmill belt

To test if your belt is tensioned correctly, slow down the treadmill to a walking speed and see how the motor reacts. If the motor slows down, then the belt is at the proper tension.

Another method you can use is lifting the belt from the middle of the machine and see how far up you can take it. It should be about 3-4 inches. If it’s higher than that, then the belt is too loose, and vice versa.