Amazing what OEM will do for performance. Haven't have any issues since forgoing aftermarket and buying GH belts. When these finally do die I will replace with GH brand again - and pick up a new PTO Pulley Tensioner Spring, too... just to be on the safe side. They do stretch over time and it's only $3, so why not?:thumbsup:
Kevlar mower belts do not stretch much.
A 1/2" over a 100" belt would be near the maximum you can expect.
They wear thin on the sides then sit deeper into the V groove so become loose.
Like most companies, Stens do two lines of belts.
One is an identical belt to the original one, most come from the same factory as the original belt with a different colour wrapping.
They also do a standard series of M, A & B section belts, also in kevlar and covered with a blue wrap
Prime line sell the same belts branded as Pix also covered with blue wrap & they are all made in Mexico.
Down side of after market belts is the wholesaler buys them in a bundle , usually 100 and then the wholesaler puts them into the sleeves so it is not unheard of to get the right sleeve with the wrong belt in it.
Some times they come unmarked & the wholesaler brands the belts as well & again belts marked wrong are no unheard of.
Then you get the "fits" belts.
These are the standard size belt closest to the original sized belt
So you get things like Cub who use 21/32" section belts that are 1/32" wider than a std 5/8" belt so you get sold one that is a little shorter to make up for the fact it sits a little deeper in the V of the pulley.
Over time pulleys wear step into the V where the belt runs so if you have been running genuine 21/32" belts for hundreds of hours the try to fit a std 5/8 section belt, it will fall apart in no time flat.