ConCar Variable Speed Belts 26x8 - 710 Li

ConCar Variable Speed Belts 26x8 – 710 mm inner length – DIN 7719 / ISO 1604

The ConCar Variable Speed Belts 26x8 with an inner length of 710 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.

This length in the drive

The inner length of 710 mm is a short version for the 26x8 profile. This means a compact center distance and a correspondingly small drive volume, but at the same time a high bending frequency. At a belt speed of 20 m/s, this equates to approximately 26.7 revolutions per second. With short belts, check whether the tapered pulleys meet the minimum running diameter specified by the manufacturer, as the bending stress has the greatest impact on service life at this point.

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 710 mm; it is measured at the inner circumference of the belt and is the standard ordering dimension in Germany. The effective length (Ld) of 750 mm refers to the neutral axis and is the dimension used in many catalogs and drive calculations. The outer length (La) of 760 mm is measured at the back of the belt. With a profile height of 8 mm, the difference between the inner and outer lengths is theoretically 50 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): 710 mm

• Effective length (Ld): 750 mm

• External length (La): 760 mm

• Profile: 26x8 according to DIN 7719 / ISO 1604

• Top width: 26 mm

• Height: 8 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: 0.175 kg

• Article number: G426080710

• EAN: 4059213021223

• Manufacturer: ConCar

Structure and materials

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 upper width of 26 mm 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 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.

Assembly and tension

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.

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.

Similar names for other brands

Variable Speed Belts are standardized according to DIN 7719 and ISO 1604. A belt with a 26x8 profile and a 710 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 26x8 / VARIO POWER 26x8

• GATES: Multi-Speed ​​26x8 / Predator V Variable Speed

• CONTITECH: VARIO Speed ​​26x8 / CONTI-V VARISPEED

• MEGADYNE: VARISECT 26x8

• MITSUBOSHI: VARI-SPEED 26x8

• BANDO: Variable Speed ​​26x8

• PIX: Variable Speed ​​26x8

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.