ConCar Variable Speed Belts 13x5 - 700 Li

ConCar Variable Speed Belts 13x5 – 700 mm inner length – DIN 7719 / ISO 1604

The ConCar Variable Speed Belts with a 13x5 profile and a 700 mm inner length, is an open-flanked, toothed 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.

This length in the drive

The inner length of 700 mm is a standard length in the mid-range for the 13x5 profile. For reference: With two pulleys of the same size, each with an effective diameter of 125 mm, the corresponding center-to-center distance is approximately 165 mm. At a belt speed of 20 m/s, the belt rotates around 27.6 times per second. This combination of moderate bending frequency and sufficient wrap is the reason why most standard 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 700 mm; it is measured at the inner circumference of the belt and is the standard ordering dimension in Germany. The effective length (Ld) of 724 mm refers to the neutral axis and is the dimension used in many catalogs and drive calculations. The outer length (La) of 732 mm is measured at the back of the belt. With a profile height of 5 mm, the difference between the inner and outer lengths is 32 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): 700 mm

• Effective length (Ld): 724 mm

• External length (La): 732 mm

• Profile: 13x5 according to DIN 7719 / ISO 1604

• Top width: 13 mm

• Height: 5 mm

• Flank angle: 24°

• 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: 0.062 kg

• Article number: G413050700

• EAN: 4059213020301

• 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 24° 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 13 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.

Typical areas of application

Belts of this size are typically found in compact drives: bench drills and small lathes with continuously variable spindle speed, feed drives on band and circular saws, laboratory centrifuges and shakers, dosing and small conveyors in packaging lines, as well as garden equipment and small drives where the installation space does not allow for large pulleys.

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

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.

Similar names for other brands

Variable Speed Belts are standardized according to DIN 7719 and ISO 1604. A belt with a 13x5 profile and a 700 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 13x5 / VARIO POWER 13x5

• GATES: Multi-Speed ​​13x5 / Predator V Variable Speed

• CONTITECH: VARIO Speed ​​13x5 / CONTI-V VARISPEED

• MEGADYNE: VARISECT 13x5

• MITSUBOSHI: VARI-SPEED 13x5

• BANDO: Variable Speed ​​13x5

• PIX: Variable Speed ​​13x5

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.