ConCar Variable Speed Belts 30x10 – 1,175 mm inner length – DIN 7719 / ISO 1604
The ConCar Variable Speed Belts 30x10 with an inner length of 1,175 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 1,175 mm is a long version for the 30x10 profile and is intended for drives with a large center distance, approximately 170 mm with two identical pulleys of 280 mm effective diameter. At 0.388 kg, this belt weighs correspondingly more than the shorter lengths of the same profile. With this length, plan for a guide or support for the slack side if the drive operates with highly variable loads, and recheck the tension after the initial break-in period.
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 1,175 mm; it is measured at the inner circumference of the belt and is the standard ordering dimension in Germany. The effective length (Ld) of 1,220 mm refers to the neutral axis and is the dimension used in many catalogs and drive calculations. The outer length (La) of 1,238 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): 1,175 mm
Effective length (Ld): 1,220 mm
External length (La): 1,238 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: 0.388 kg
Article number: G430101175
EAN: 4059213022220
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 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.
Variable Speed Belts are supplied as continuous, single belts and cannot be shortened or joined. Before installation, the tapered pulleys must be fully opened so that the belt can be positioned at its smallest effective diameter. Tensioning is then achieved via the pulley's adjustment range or the motor rocker arm. Prying the belt open by the pulley edge is particularly damaging with Variable Speed Belts , as this can damage the exposed flanks and the tension member without any visible external damage.
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 30x10 profile and an inner length of 1,175 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.