ConCar Variable Speed Belts 70x18 - 2000 Li

ConCar Variable Speed Belts 70x18 – 2,000 mm inner length – DIN 7719 / ISO 1604

The ConCar Variable Speed Belts with a 70x18 profile and a 2,000 mm inner length, is an open-flanked, toothed variator belt conforming to DIN 7719 and ISO 1604. It transmits drive power exclusively via its two flanks, moving radially on the conical, axially displaceable pulley halves during operation. This movement is the principle behind a mechanical speed converter: when one pulley closes, it pushes the belt outwards to a larger effective diameter, while on the opposite side it slides inwards. This allows the transmission ratio to change continuously without the need for shifting, clutching, or electronic control.

This length in the drive

With an inner length of 2,000 mm, this belt falls within the mid-length range of the 70x18 profile and thus offers the most favorable ratio of bending stress to tensile stress. For two identical pulleys with an effective diameter of 500 mm, this results in a center-to-center distance of approximately 255 mm. This is the range in which variator drives are typically designed, because the tension travel, wrap, and belt mass are well-matched.

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 2,000 mm; it is measured at the inner circumference of the belt and is the standard ordering dimension in Germany. The effective length (Ld) of 2,085 mm refers to the neutral axis and is the dimension used in many catalogs and drive calculations. The outer length (La) of 2,113 mm is measured at the back of the belt. With a profile height of 18 mm, the difference between the inner and outer lengths is 113 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.

Dimensions and specifications

• Internal length (Li): 2,000 mm

• Effective length (Ld): 2,085 mm

• External length (La): 2,113 mm

• Profile: 70x18 according to DIN 7719 / ISO 1604

• Top width: 70 mm

• Height: 18 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: 2.74 kg

• Article number: G470182000

• EAN: 4059213024798

• Manufacturer: ConCar

Structure and materials

The belt consists of a chloroprene rubber core with a longitudinally inserted polyester cord as a tensile member. The flanks are open, meaning they are not covered with fabric. This noticeably increases the coefficient of friction on the pulley and thus improves the transmissible torque, but in return requires clean, unworn pulley flanks. The compound is antistatically conductive according to ISO 9563, which allows the belt to be used in dusty areas and in ATEX-relevant environments.

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, ensuring smooth belt operation across the entire pulley adjustment range and preventing binding at the end positions. Simultaneously, the large 70 mm upper width provides the necessary contact area to transmit torque solely through friction. The 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.

Typical areas of application

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.

Assembly and tension

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.

A typical wear pattern in the variator is glassy, ​​shiny edges. This is not a sign of aging, but rather slippage: the belt slips under load and polishes the edge. The cause is almost always insufficient tension or a worn pulley with an enlarged groove width. If only the belt is replaced and the pulley remains the same, the damage usually recurs within a few weeks.

Similar names for other brands

Variable Speed Belts are standardized according to DIN 7719 and ISO 1604. A belt with a 70x18 profile and a 2,000 mm inner length 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 70x18 / VARIO POWER 70x18

• GATES: Multi-Speed ​​70x18 / Predator V Variable Speed

• CONTITECH: VARIO Speed ​​70x18 / CONTI-V VARISPEED

• MEGADYNE: VARISECT 70x18

• MITSUBOSHI: VARI-SPEED 70x18

• BANDO: Variable Speed ​​70x18

• PIX: Variable Speed ​​70x18

Delivery

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.