ConCar Variable Speed Belts 30x10 – 1,035 mm inner length – DIN 7719 / ISO 1604
The ConCar Variable Speed Belts with a 30x10 profile and an inner length of 1,035 mm, is an open-flanked, molded-tooth 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 precisely the principle of 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.
With an inner length of 1,035 mm, this belt falls within the mid-range of the 30x10 profile and thus offers the most favorable ratio of bending to tensile stress. For two identical pulleys with an effective diameter of 224 mm, this results in a center-to-center distance of approximately 190 mm. This is the range in which variator drives are typically designed, as 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 1,035 mm; it is measured at the inner circumference of the belt and is the standard ordering dimension in Germany. The effective length (Ld) of 1,080 mm refers to the neutral axis and is the dimension used in many catalogs and drive calculations. The outer length (La) of 1,098 mm is measured at the back of the belt. With a profile height of 10 mm, the difference between the inner and outer lengths is 63 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): 1,035 mm
Effective length (Ld): 1,080 mm
External length (La): 1,098 mm
Profile: 30x10 according to DIN 7719 / ISO 1604
Top width: 30 mm
Height: 10 mm
Flank angle: 27°
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: 0.342 kg
Article number: G430101035
EAN: 4059213022183
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 27° 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 30 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 cover the classic field of industrial variators: feed and grinding belt control in woodworking machines, demand-controlled piston and screw compressors, spinning and drawing units in textile machines, industrial mixers and kneaders with soft start, take-off and screw drives on plastic extruders, as well as boring mills and lathes with stepless control.
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.
Transverse cracks on the underside indicate an insufficient bearing diameter or cold brittleness, while longitudinal cracks and frayed edges point to misalignment between the pulleys. It's worthwhile checking the alignment with a ruler or laser when changing the belt, as even a few millimeters of misalignment over a one-meter center-to-center distance can halve the belt's lifespan.
Variable Speed Belts are standardized according to DIN 7719 and ISO 1604. A belt with a 30x10 profile and an inner length of 1,035 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 30x10 / VARIO POWER 30x10
GATES: Multi-Speed 30x10 / Predator V Variable Speed
CONTITECH: VARIO Speed 30x10 / CONTI-V VARISPEED
MEGADYNE: VARISECT 30x10
MITSUBOSHI: VARI-SPEED 30x10
BANDO: Variable Speed 30x10
PIX: Variable Speed 30x10
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.