I always get a kick out of the ridiculous belt sizes that Bolens specified. 114-5/32" or even 114-1/4"? Really?! Was this just some Bolens engineers idea of comedy? A 114-5/32" belt is only ~0.137% longer than a 114" belt and 114-1/4" belt is only ~0.22% longer than a 114" belt. Did they update the size from 114-5/32" to 114-1/4" to make it seem to be more of a "standard" size? That, too, is ridiculous, because the difference between the two sizes is only ~0.08%. Would it have been that difficult to have tweaked the design of the deck such the belt length would be a nice, even, standard size number, or did they do it so that you'd have to buy a genuine Bolens "correct size" belt?
Considering the fact that these decks have dual spring-loaded idler pulleys, do these minuscule length differences really make a difference? A 1/2" (A) x 114" belt is readily available from many sources, for relatively low cost, (some are really cheap - quality unknown), whereas the correct size... not so much. The deck's idler assembly, with it's long return spring, seems as though it would be fairly tolerant of minor belt length differences, although I don't think I've ever tried a standard 114" belt on my 42" deck (18421). Wouldn't a 114" belt work?
Sorry, not trying to take business away from anyone, but it would be nice to know that a standard size belt, which one could pick up locally, would work in an emergency. Besides, there will always be people who want the correct size.
With alot of quality manufactures such as wheel horse John Deere Bolens ect, I think they made the machine or attachment first then built a belt for and around that particular application , They never went with the flow and often used their own style sheaves and gearboxes whereas alot of other manufactures all used sourced components where they could have industry standard belts.
I have spent about 7 years now researching belts and interchanging the Bolens ones with exact spec equivalents when possible and probably know way more than I should about belt design and technology LOL. I even spent an afternoon with a belt rep cutting the various brands of belts to see how they stack up.
For example Bolens used special angles and materials that cannot compare to the napa special fractional HP belt for $10 which offers on average only 3 inner cords and no kevlar material to speak of.
A Bolens 31'' belt will in most cases not be a "modern" 31'' size , If you put them on a belt measure you will see that. There was a reason behind their madness and alot of research and engineering went into selecting the components they used, thats one of the reasons the Bolens belts and the OEM spec belts offered today last as long as they do while you only get 1-3 years out of a FHP auto belt that was not designed for that application.
I mainly do it out of habit. This belt in peticular is not as critical as some others, so yes a straight 114" belt will work. Will it last as long as the correct belt? Generally speaking, no. As Brian stated, the OEM belts were engineered to fit the machines properly. There are many factors that go into these belts. Many have special top widths, special angles, thickness, v groove and overall construction, whether it's a wrapped belt, raw edge, banded, Kevlar and etc.
Overall, I believe that it is in the interest of our Bolens community to offer the correct information to the best of our ability, even on something as simple (or complex) as a v-belt.