Interesting, though, that the belt wasn't uniformly frayed, just on maybe 1/3 of it, suggesting it could just be a poor quality belt with excess variance in thickness.?
A significant part of the belt has already frayed as a result. Drove it into the garage, pulled the deck and can see the issue - there is a bolt sticking up from the bottom of the deck near the idler pulley that is contacting the belt at certain points. Installed the belt, tension seemed right, figured I was good to go. Bought a Dayco v-belt at Fleet Farm to replace a cracked OE secondary drive belt (the one that weaves through the pulleys on the mower deck) on my 1996 John Deere LX-176 with 44 inch Piranha deck.
