What’s the best tension for my drive?

A general rule of thumb is that tension can be estimated by measuring the deflection of the belt at the middle of the span.  Under proper tension, the deflection should be about 1/64th the center distance.

A closer estimate can be obtained from the table below.

Belt section	Small sheave dia.		Tension in lbs.
			Wrapped belt		Cogged belt
			Installation	Re-Tension	Installation	Re-Tension
3V / 3VX		≤ 2.80”	45	35	55	45
	> 2.80”	≤ 3.65”	55	45	70	55
	> 3.65”	≤ 5.00”	80	55	90	70
	> 5.00”		Must be calculated
5V / 5VX		≤ 6.30”	150	110	160	120
	> 6.30”	≤ 9.00”	160	120	190	150
	> 9.00”	≤ 14.00”	200	160	220	180
	> 14.00”		Must be calculated
A / AX		≤ 3.15”	35	25	45	35
	> 3.15”	≤ 4.12”	45	35	55	45
	> 4.12”	≤ 5.20”	70	55	90	70
	> 5.20”		Must be calculated
B / BX		≤ 4.90”	70	55	100	80
	> 4.90”	≤ 6.30”	90	70	110	90
	> 6.30”	≤ 8.00”	70	55	90	70
	> 8.00”		Must be calculated
C / CX		≤ 8.00”	160	110	180	140
	> 8.00”	≤ 9.75”	180	140	200	160
	> 9.75”	≤ 14.00”	200	160	220	180
	> 14.00”		Must be calculated

The exact tension depends on specific drive information: the diameters of the sheaves, the center distance, the speed and horsepower, etc.  Contact our sales personnel for a drive calculation tailored to your specific drive.