Proform 525 Space Saver Belt Change is really hard.


Watch an online video so you have an idea of what you will be doing. However, changing the belt on a Profom 525 Space Saver is a bit different than what the videos show for other types of treadmills. It is a lot harder and makes you swear a lot. It took me over three hours, but with these instructions I could have done it in about an hour. Note you do not need to remove the cover on the underside of the running board (they tell you to do this for in the video for the 525 ssi, but you do not need to remove it here).

Ignore the videos that say only remove one side. That is not going to work with this treadmill. You must remove the entire running board to get the belt on.

To remove the bottom cover, you must remove both adjusting bolts entirely. This is the only thing that holds the cover in place. Then you can just tap the cover off with a hammer but be gentle and take turns tapping on each side.

The front cover is easy to remove, and you only need to remove one bolt to be able to slide the top pulley out.

The side rails are stapled in place and you cannot see the staples. You will need to slide a screwdriver under and pry the staples out. Be careful, or the side rails will crack. The staples may pull through the side rail plastic – no big deal. Just pull the staples out of the board later. If any staples remained stuck in the side rails, you will need to remove them.

Removing the six screws that hold the running board in place is easy and obvious.

When you remove the belt, there are metal brackets hanging below the running board. The belt goes in between them. You have to pull the belt over the bracket to get it off. You cannot see the bracket until you remove the running board.

To get the belt on the running board, remove the board entirely, lubricate the board, and put the belt on the board. Lay the board in place, but do not put the screws back. Then slide the top pulley into the belt and put the top pulley back in place. Be sure to line up the drive belt properly. Once it is tight, you cannot move it. Replace the bolt that holds the top pulley in place.

When screwing the board back in place, use a tiny screwdriver to line up the holes. One screw on each side is pointy, that screw goes at the bottom. Be careful not to over-tighten the screws.

When re-installing the side rails, throw away the screws that come with your new belt from Treadmill Doctor. They are too small, too fine thread, and too short and will just pull out of the MDF. Use #6 drywall screws 1” long, or staples if you have a commercial staple gun.

When reinstalling the bottom roller and cover:

A. Cut a long piece from a wire clothing hanger for each side. Run it through the holes to keep the screw holes in the bottom pulley lined up while you beat the cover into place. This is critical and saves you hours of frustration and do overs.

B. I gave up on the ground wire. It was impractical to get it back into place. It may be redundant anyway, the motor is already grounded. However it is a safety feature, so you might want to put it back in place. Fight with the dang thing if you wish. Good luck.

C. The bottom cover is hard to slide into place, it tends to hang up. You have to get the two sides to go in place evenly. You can beat on it a bit, but not too hard or you will crack it.

D. Tighten the adjusting bolts five turns each side alternating sides until they are completely tight as far as they can go. Then back off five turns on each side. This is more practical than trying to count the number of turns while you are installing it. You will never know when the threads start catching, so the count will be off. These bolts turn hard – really hard. Maybe something was wrong with the threads on mine.

12. Once you have the bottom cover on you can adjust the belt so it centers, and you are good to go (don’t forget to put the top cover back on at some point).

By the way, the belt from Treadmill Doctor fit perfectly and appears to be good quality. Also it arrived in only two days.


  • Thank you for sharing! I know these words will resonate with quite a few people!!!!

    Thank you also for the compliments on the belt - we appreciate comments such as these!

    Here are a few of our thoughts::

    all installations are not the same - if you take reasonable care, our screws work the best.

    If you have a 3/4” deck and use a 1” screw, you are likely to shred the edge of your new belt with the tip grazing the underside of the belt as it comes around.

    Also - you have to be careful not to tighten the adjusting bolts too hard!

    glad you were able to get your belt changed out! We have stopped sending instructions but have videos available on our site.

    thank you again and have a great day!
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