ConCar Variable Speed Belts 47x13 – 1,800 mm inner length – DIN 7719 / ISO 1604
This ConCar Variable Speed Belts with a 47x13 profile and an inner length of 1,800 mm, is a toothed variator belt conforming to DIN 7719 and ISO 1604. Variable Speed Belts are the mechanical alternative to frequency converters: they regulate the output speed purely through geometry, without electronics, harmonics, or an additional heat source in the control cabinet. In many woodworking, textile, and agricultural machines, this remains the more robust solution because it operates reliably even in dusty, humid, and vibration-prone environments.
With an inner length of 1,800 mm, this belt is one of the longer versions of the 47x13 profile. With two equally sized pulleys with an effective diameter of 450 mm, this corresponds to a center distance of approximately 225 mm. Long belts are less prone to bending stress; at 20 m/s, they rotate only about 10.8 times per second. However, they require more attention to tension: the slack side tends to flutter with large center distances, and the belt's own mass generates additional centrifugal force during operation, which reduces the contact pressure on the pulley.
For design and comparison with an existing belt, the three length specifications are important because manufacturers use different reference dimensions. The inner length (Li) is 1,800 mm; it is measured at the inner circumference of the belt and is the standard ordering dimension in Germany. The effective length (Ld) of 1,860 mm refers to the neutral axis and is the dimension used in many catalogs and drive calculations. The outer length (La) of 1,882 mm is measured at the back of the belt. With a profile height of 13 mm, the difference between the inner and outer lengths is 82 mm, which corresponds to twice the difference in circumference across the belt height. When replacing an old belt, always compare using the same reference dimension; otherwise, you can easily be off by several centimeters.
Internal length (Li): 1,800 mm
Effective length (Ld): 1,860 mm
External length (La): 1,882 mm
Profile: 47x13 according to DIN 7719 / ISO 1604
Top width: 47 mm
Height: 13 mm
Flank angle: 28°
Construction: open-sided, toothed
Mixture: Chloroprene (CR)
Tensioning material: Polyester cord
Antistatic: yes, according to ISO 9563
Temperature range: -30 °C to +80 °C
Belt speed: up to 30 m/s
Weight: 1.38 kg
Article number: G447131800
EAN: 4059213023883
Manufacturer: ConCar
The belt consists of a chloroprene blend (CR) with an embedded polyester tensile cord. Chloroprene was deliberately chosen here: it is resistant to oil mist, ozone, UV radiation, and weathering, and retains its elasticity in a temperature range of approximately -30 to +80 degrees Celsius. The polyester cord absorbs the tensile forces and keeps elongation low over the belt's lifespan, which is particularly important in a variator because an elongated belt length directly translates into a shift in the control range.
The 28° flank angle is the crucial difference compared to a conventional V-belt, which operates at 34 to 40 degrees. The shallower angle generates less wedging effect per millimeter of radial travel, allowing the belt to run smoothly across the entire adjustment range of the pulleys and preventing binding at the end positions. Simultaneously, the large upper width of 47 mm provides the necessary contact area to transmit torque solely through friction. The shaped toothed underside reduces bending stiffness to such an extent that the belt can operate even on small effective diameters without the flanks overheating due to internal flexing.
Belts of this size are used in heavy-duty drives: threshing and drum drives on combine harvesters, intake and chopping units on forage harvesters, sawing and chipboard plants, large conveying and crushing plants, as well as compressor and blower drives where the speed must follow the demand without shifting a gearbox.
What these applications have in common is that the rotational speed must be adjusted during operation to suit the material, batch, or demand. A Variable Speed Belts solves this problem purely mechanically, without any electronics in the drive train. This is advantageous wherever dust, moisture, vibration, or temperature would damage a frequency converter, and it remains the only economical solution for existing machines because the variator is an integral part of the machine's design.
Before ordering, check the adjustment range of your drive. The belt must be able to be fitted without force, whether the pulleys are fully closed or open. After fitting, tension the belt to the tension specified by the machine manufacturer and check again after the break-in period. If several belts run in parallel in one drive, they must always be replaced as a complete set, as a new belt, in addition to worn ones, bears the entire load.
Before you classify a belt as worn, it's worth taking a look at the pulley. A worn groove allows the belt to sink deeper, causing it to sit on the bottom of the groove and lose contact with the belt flanks. This manifests as a sudden loss of power, even with a seemingly new belt. This can be checked in a minute using a groove feeler gauge.
Variable Speed Belts are standardized according to DIN 7719 and ISO 1604. A belt with a 47x13 profile and an inner length of 1,800 mm is therefore dimensionally identical regardless of the manufacturer; no modification of the pulleys is required for replacement. This ConCar belt replaces, among others:
OPTIBELT: VB 47x13 / VARIO POWER 47x13
GATES: Multi-Speed 47x13 / Predator V Variable Speed
CONTITECH: VARIO Speed 47x13 / CONTI-V VARISPEED
MEGADYNE: VARISECT 47x13
MITSUBOSHI: VARI-SPEED 47x13
BANDO: Variable Speed 47x13
PIX: Variable Speed 47x13
The belt is supplied as a single, endless belt. Standard lengths and common profiles are available from stock; custom lengths and widths are available upon request. If you are unsure which length your drive requires, please send us the part number of your old belt or the dimensions of your pulleys, and we will check the compatibility.