ConCar Variable Speed Belts 55x16 – 1,900 mm inner length – DIN 7719 / ISO 1604
The ConCar Variable Speed Belts 55x16 x 1900 Li is a flank-driven variator belt according to DIN 7719 and ISO 1604 with a molded toothed underside. The transversely molded teeth are not a tooth profile in the sense of a toothed belt; they do not engage with the pulley. Their purpose is to reduce bending stiffness so that the belt can be bent even on small running diameters without the flanks tearing or the belt heating up due to internal flexing.
The inner length of 1,900 mm is a standard length in the mid-range for the 55x16 profile. For reference: With two pulleys of the same size and an effective diameter of 500 mm, the corresponding center distance is approximately 200 mm. At a belt speed of 20 m/s, the belt rotates around 10.1 times per second. This combination of moderate bending frequency and sufficient wrap is the reason why most series production drives operate within this length range.
For design purposes and comparison with an existing belt, the three length specifications are important because manufacturers use different reference dimensions. The inner length (Li) is 1,900 mm; it is measured at the inner circumference of the belt and is the standard ordering dimension in Germany. The effective length (Ld) of 1,975 mm refers to the neutral axis and is the dimension used in many catalogs and drive calculations. The outer length (La) of 2,001 mm is measured at the back of the belt. With a profile height of 16 mm, the difference between the inner and outer lengths is 101 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): 1,900 mm
Effective length (Ld): 1,975 mm
External length (La): 2,001 mm
Profile: 55x16 according to DIN 7719 / ISO 1604
Top width: 55 mm
Height: 16 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: 1.97 kg
Article number: G455161900
EAN: 4059213024439
Manufacturer: ConCar
In terms of materials, ConCar combines a chloroprene body with a polyester tensile member. This pairing is the industry standard for variator belts because it simultaneously fulfills two opposing requirements: The belt must be flexible enough to bend over a small diameter, yet stiff enough longitudinally to resist flexing under load. Antistatic treatment according to ISO 9563 is standard on ConCar belts and is not an additional cost option.
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 55 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.
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.
For installation: Open the pulleys, place the belt on without tension, then adjust it to the required tension using the adjustment mechanism or the motor rocker. The belt must never be pulled over the pulley edge or pried open with a tool. After approximately 24 hours of operation, the belt will have settled; at this point, the tension should be checked a second time and adjusted if necessary. Insufficient tension leads to slippage and burns the belt edges, while excessive tension puts unnecessary stress on the bearings and tension members.
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.
Variable Speed Belts are standardized according to DIN 7719 and ISO 1604. A belt with a 55x16 profile and a 1,900 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 55x16 / VARIO POWER 55x16
GATES: Multi-Speed 55x16 / Predator V Variable Speed
CONTITECH: VARIO Speed 55x16 / CONTI-V VARISPEED
MEGADYNE: VARISECT 55x16
MITSUBOSHI: VARI-SPEED 55x16
BANDO: Variable Speed 55x16
PIX: Variable Speed 55x16
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.