ConCar narrow V-belt SPZ - 1120 Lw

ConCar narrow V-belt SPZ – 1,120 mm effective length – DIN 7753 / ISO 4184

The ConCar SPZ narrow V-belt with an effective length of 1,120 mm is a sheathed, high-performance V-belt conforming to DIN 7753 Part 1 and ISO 4184. Narrow V-belts transmit power via their two flanks, which engage the groove of the pulley at a 40-degree angle. This wedge action creates a normal force that is many times greater than the applied preload, and this force is precisely what generates the friction that transmits the torque.

This length in the drive

The effective length of 1,120 mm is a standard length for the SPZ profile. For reference: With two pulleys of the same size and a 180 mm center diameter, the center distance is approximately 275 mm. At a belt speed of 25 m/s, the belt rotates approximately 22.3 times per second. For drives with unequal pulley diameters, ensure a wrap angle of at least 120 degrees on the smaller pulley; below this, the transmissible power drops noticeably.

For ordering and comparing with an existing belt, the three length dimensions are important because different manufacturers use different reference dimensions. The effective length (Lw, sometimes Ld) is 1,120 mm. This is the standard dimension for narrow V-belts and is therefore included in the product description. The inner length (Li) is 1,082 mm, and the outer length (La) is 1,133 mm. For the SPZ profile, the fixed distances according to DIN 7753 are Li = Lw − 38 mm and La = Lw + 13 mm.

Dimensions and specifications

• Effective length (Lw / Ld): 1,120 mm

• Internal length (Li): 1,082 mm

• External length (La): 1,133 mm

• Profile: SPZ according to DIN 7753 Part 1 / ISO 4184

• Top width: 9.7 mm (nominal size 10 mm)

• Height: 8 mm

• Flank angle: 40°

• Construction: sheathed, rubberized fabric casing

• Mixture: Chloroprene (CR)

• Tensioning material: Polyester cord

• Antistatic: yes, according to ISO 1813

• Temperature range: -30 °C to +80 °C

• Belt speed: up to 40 m/s

• Recommended minimum guide diameter: 63 mm

• Suitable pulleys: Narrow V-belt pulleys according to DIN 2211, profile SPZ

• Manufacturer: ConCar

Structure and materials

The belt consists of a chloroprene rubber core with a longitudinally inserted polyester cord as a tensile member, surrounded by a rubberized fabric cover. The polyester cord absorbs the tensile forces and ensures minimal elongation, while the fabric cover carries wear on the groove flank and distributes the force evenly into the core. This construction is the reason why a sheathed belt continues to operate reliably even with dirty or slightly tarnished pulleys.

The flank angle of 40 degrees is the same for all narrow V-belts and corresponds to the groove geometry according to DIN 2211. The difference to the classic V-belt according to DIN 2215 lies in the width-to-height ratio: The SPZ profile has a top width of 9.7 mm and a height of 8 mm. This positions the tensile member further from the groove base, resulting in a larger flank area relative to the belt height, and thus allowing the belt to transmit significantly more power within the same installation space.

Typical areas of application

The SPZ profile is the entry-level option for narrow V-belts and is used wherever space is limited: fans and blowers in air conditioning and ventilation systems, dust extraction systems, small compressors, drilling and grinding machines, lawnmowers and garden equipment, and pumps in building services engineering. For power outputs up to approximately 4 kW per belt, SPZ is usually the most compact solution without sacrificing the power density of a narrow V-belt profile.

Assembly and tension

For installation: Reduce the center distance, place the belt without tension, then tighten it to the required tension. Never pull the belt over the pulley edge or pry it open with a screwdriver. Doing so will cause individual cord threads in the tension member to break, which remains invisible from the outside and will cause the belt to fail after only a few hours of operation.

If several belts are running in parallel, always replace the entire set. A new belt next to worn ones will have less stretch and will essentially carry the entire load while the old ones continue to run. This results in the new belt failing after a short time and leading to the suspicion that the quality was substandard. ConCar manufactures belts with precise length tolerances, so belts from the same batch can be used as a set without pre-sorting.

Similar names for other brands

Narrow V-belts are standardized according to DIN 7753 Part 1 and ISO 4184. A belt with profile SPZ and an effective length of 1,120 mm is therefore dimensionally identical regardless of the manufacturer and will run in your existing pulleys without modification. This belt replaces, among others:

• OPTIBELT: SK SPZ / SUPER X-POWER SPZ

• GATES: Super HC SPZ / Delta Narrow Wedge SPZ

• CONTITECH: CONTI-V ADVANCE SPZ

• MEGADYNE: Oleostatic SPZ

• MITSUBOSHI: Wedge SPZ

• BANDO: Power Ace SPZ

• PIX: X'set SPZ

Delivery

The belt is supplied as a single, endless belt. Standard lengths are available from stock, and delivery is available throughout the EU. For multi-belt drives, please specify the required quantity, and we will assemble the order from a single batch.