ConCar Variable Speed Belts 37x10 – 1,060 mm inner length – DIN 7719 / ISO 1604
The ConCar Variable Speed Belts 37x10 with an inner length of 1,060 mm is a variator belt compliant with DIN 7719 and ISO 1604, designed for continuous operation in continuously variable speed drives (CVTs). Unlike a conventional V-belt, which runs on a fixed diameter, a Variable Speed Belts must maintain consistent friction across the entire adjustment range of the pulleys. To achieve this, it is significantly wider than it is tall and has a shallower flank angle, ensuring that the wedge effect remains uniform across the entire radial path and preventing the belt from binding or slipping at the end positions.
The inner length of 1,060 mm is a standard length in the mid-range for the 37x10 profile. For reference: With two pulleys of the same size and an effective diameter of 250 mm, the corresponding center distance is approximately 160 mm. At a belt speed of 20 m/s, the belt rotates around 18.1 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 and comparison with an existing belt, the three length specifications are important because manufacturers use different reference dimensions. The inner length (Li) is 1,060 mm; it is measured at the inner circumference of the belt and is the standard ordering dimension in Germany. The effective length (Ld) of 1,105 mm refers to the neutral axis and is the dimension used in many catalogs and drive calculations. The outer length (La) of 1,123 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): 1,060 mm
Effective length (Ld): 1,105 mm
External length (La): 1,123 mm
Profile: 37x10 according to DIN 7719 / ISO 1604
Top width: 37 mm
Height: 10 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: 0.506 kg
Article number: G437101060
EAN: 4059213023081
Manufacturer: ConCar
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 37 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.
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.
Variable Speed Belts are standardized according to DIN 7719 and ISO 1604. A belt with a 37x10 profile and an inner length of 1,060 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 37x10 / VARIO POWER 37x10
GATES: Multi-Speed 37x10 / Predator V Variable Speed
CONTITECH: VARIO Speed 37x10 / CONTI-V VARISPEED
MEGADYNE: VARISECT 37x10
MITSUBOSHI: VARI-SPEED 37x10
BANDO: Variable Speed 37x10
PIX: Variable Speed 37x10
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.