When you buy a treadmill the underside of the walking belt is prelubricated, and the belt/deck system has a friction coefficient (FC) that is optimal per the oem. Inevitiblity, as time goes on the FC level increases (from change in material from use, and the amount of silicone between the belt and deck), thus causing more stress on vital treadmill components ***. The good news is with periodic maintenance you can dramatically slow this natural progression down.
Due to the fact liquid Silicon evaporates (with or without use) it is recommended you apply it every 3-4 months. This is not novel information, but alot of people take the information and try to hack it by using a spray bottle and squirting little bits of silicon on the edge while it's folded up, or worse unfolded... Unfortunately, the silicon never reaches the center of the belt where your feet are striking the surface thus is ineffectual. Technically, the proper way to apply lubricant is to take tension off the belt at the rear roller, with that newly created slack you can really get to the underside of the belt at the center. The last step is realign and re-tension the belt at the rear roller as before, kind of a pain, no?
There is one tool that serves as a work around, that is the treadlube applicator and sponge. Simply put, it allows you to apply silicon to the sponge end and with its extension get in to the right underside section of the belt, in the center as described above. We sell them through the link below, lowest price you'll see with shipping.
*** Vital components like motors and motor control boards fry with high friction loading because the motor requires more amperage to turn the belt system plus user, plus the higher friction. That current is surging through that board and will cause it to fail once it passes the tolerable amperage level.. We've seen people replace 3 boards before discovering they never applied lubricant to their belt and deck., putting more boards in will not fix friction coefficient, it will only drain your wallet in terms of service calls.. In other words, Lower Circuit board failures are usually not board failures but belt and deck failures due to poor maintenance.