This information is taken from Allis-Chalmers dealer product information, 1967, that was used to help salesmen understand and address customer questions about belts. It's provided here to help you understand the importance of quality belts -- note especially the last part
Facts About Belts Used on Garden Tractors
Belts in General
Belts are a flexible, highly efficient means of transmitting power. Power by means of belts can be transmitted around corners without expensive gear or bevel gear drives. If properly designed, and quality belts are used, belt drives provide rugged long-life service. In fact, there isn't a car manufactured that doesn't use belts - for fan belt, air
conditioner, or generator parts, etc., and most of these belt drives on cars transmit more power than do belt drives on garden tractors.
Heavy-duty agricultural machinery like a grain or corn harvester, costing up to and in excess of $15,000 use belt drives very successfully. (NOTE: That
$15,000 price is 1967 would likely be over $100,000 today ... Kent)
Belt Drives on Garden Tractors
All garden tractor manufacturers use belt drives on their units. Many tractor manufacturers advertise "no belt drives," meaning they do not use a belt drive clutch assembly. Yet, where the most power is needed, and the greatest amount of engine horsepower is transmitted, namely for operating a rotary mower, snow blower or tiller, they use belt drives. It
appears contradictory to advertise "no belt drives" as a selling point, and at the same time use belt drives where the most horsepower is transmitted.
Belt vs. Mechanical Clutch
Some manufacturers claim that their drive from the engine to the transmission is better than a belt drive because they use a mechanical clutch. Allis-Chalmers experience proved you can obtain longer life and better wearing characteristics by using quality, oil and heat resistant belts with back side idler pulleys as clutches. With this clutch belt drive you can ride
the clutch for slow starts or slip the clutch under heavy loads for long periods of time without excessive wear on parts. This is not the case with units using a mechanical clutch. Slipping the clutch would burn up the clutch and mean costly replacement of parts.
One reason a belt gives exceptionally
good clutch life is because a new surface of the belt is constantly present at the point where one slips the clutch, while the remainder of the belt is cooled by running in air. This is similar to the design used in the disc brakes on modern high performance automobiles.
An additional benefit of using a
belt clutch is that it is easy and inexpensive to service, while the replacement of mechanical clutch parts is costly and m ea n s a time consuming breakdown.
Unfortunately, some manufacturers who use belt drives do not use quality belts. There are two important factors in a belt drive - the type of belt used and the design of the belt drive itself. Allis-Chalmers uses quality, oil and heat resistant belts which are specially designed. These specially designed belts are then tested in each
belt drive application to be sure of proper performance.
[Source: Allis-Chalmers Outdoor Power Equipment, Riding Tractors and Implements Product Information, OPE-1012, Jan 67, courtesy of Del Allen]