Originally posted by ferrealb16
is that what deflection is? damn, i always thought deflection meant the distance a belt, chain, or cable moves up and down. think about it, when you work on a motox bike or what not, you cannot twist the drive chain, you simply move it up and down, with a ruler to see how much movement it has up and down. i know im a newbie, but im not, get my drift?
Belts twist and twisting is the preferred way to measure slack in a belt. True that the distance it moves from center is the amount of deflection, however, it is much faster [and more accurate] to measure belt tension by twist since belts naturally stretch, and you don't want them to have so much slack that they don't do their job, but not so tight that they just wear out. Generally 1/8th to 1/4 [90 degrees] of twist is correct on a belt. On a chain, deflection depends on application, but not the same rules as a belt since too tight or too loose means that the sprockets get accelerated wear, and sprockets are much more expensive than belts, which do not eat up pulleys.