It's possible that your treadbelt needs lubrication, or simply adjusting. Here is a tutorial on adjusting your treadbelt:
Here is one link to purchase a lube kit, there are probably many others online also:
Should you actually need to purchase a new treadbelt, I would try to identify which specific model of the Proform 530 you have from this list and then in the parts list for that treadmill scroll down to "Treadbelt"
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It's possible that your treadbelt needs lubrication, or simply adjusting. Here is a tutorial on adjusting your treadbelt:
Here is one link to purchase a lube kit, there are probably many others online also:
Should you actually need to purchase a new treadbelt, I would try to identify which specific model of the Proform 530 you have from this list and then in the parts list for that treadmill scroll down to "Treadbelt"