Conti Synchroflex AT20 GEN III 1100

Conti Synchroflex AT20 GEN III 1100 – endless timing belt for precise industrial drives

When a timing belt needs to be replaced correctly, the profile, pitch length and number of teeth are the first data that must be correct. The Conti Synchroflex AT20 GEN III 1100 has the AT20 GEN III profile, 20 mm tooth pitch, 1100 mm pitch length and 55 teeth. This makes the product unique in terms of length and profile, while the belt width is selected separately on the product side. The belt is manufactured as an endless Conti Synchroflex PU timing belt with steel cord. The GEN III version is the reinforced high-performance construction with red high-performance polyurethane and a denser, two-filament steel cord. It should therefore be treated as a separate product series and not as the regular standard version.

Dimensions, profile and number of teeth

• Pitch length: 1100 mm
• Number of teeth: 55
• Tooth profile: AT20 GEN III
• Tooth pitch: 20 mm
• Material: cast polyurethane with steel cord
• Brand: Conti Synchroflex

The technical data below describes the part of the product that does not change when a different belt width is selected. Pitch length, tooth pitch and number of teeth remain identical for all width choices. However, the width affects the available belt cross-section width and the price calculated on the product page. Correct sizing must always take into account torque, speed, number of teeth in mesh, pulley diameters, service factor and any counter-bending.

Function of the tooth profile

The metric AT geometry has trapezoidal teeth with a larger tooth volume than the standard T profile. The purpose is to distribute the load advantageously in the tooth mesh and achieve higher tooth strength without making the drive unnecessarily large. The profile requires suitable AT timing belt pulleys with the same pitch; a visual similarity to other profiles is not evidence of compatibility.

Belt construction

With the cast manufacturing method, the finished belt becomes an exact copy of a precision-machined shape. This is a major reason for the uniform tooth pitch and reproducible length. The steel cord is integrated into the polyurethane and contributes to position and angular precision. The design is suitable for synchronous drives, where a conventional elastic friction belt does not provide the desired repeatability.

Standard, GEN III or DL ​​– this version

The red GEN III construction is not just a color variant. It is developed with higher cord density and a special steel cord construction that provides increased tensile strength, better grooveing and the ability to carry higher loads. The catalog also specifies a temperature range up to +100 °C. Standard and GEN III must therefore be created and selected as separate products, even when the length and profile are the same.

Areas of application

The profile series is used in practice for tasks such as heavy-duty drives, textile machinery, printing machinery, machine tools and larger industrial power transmissions. Common to these machines is the need for a fixed transmission ratio and controlled tooth engagement. A timing belt can transmit both force and position, but the capacity cannot be assessed based on length alone. Width, profile version, wrap angle and load cycle are among the data that must be included in the selection.

How the width variants work

This product line has been created with 16 mm as the base width because this is the width of the selected item and thus the SKU used for inventory control. Integer widths from 16 to 50 mm can be selected on this product page. The widths that appear as standard widths in the supplier data are marked separately in the options. The price surcharge is calculated as a percentage of the base width: doubling the width results in a surcharge of 100%. The technically necessary width should be selected according to the load and not only according to the price.

The discs are part of the overall solution

A belt with the correct length can still function poorly if the pulleys have the wrong profile, are worn or are misaligned. Therefore, check the tooth grooves, flanges, shaft alignment and the number of teeth on the pulleys. For the AT20 GEN III, the nominal tooth pitch is 20 mm. The fixed tooth mesh makes the gear ratio reproducible, but only when the belt has sufficient wrap and does not run with constant side pressure.

Splice, alignment and pre-tensioning

The timing belt pulleys must be parallel and in the same plane. Even minor misalignments can cause the belt to move towards a flange and cause edge or cord damage. The belt should be installed without being twisted, sharply bent or pressed over a flange with a tool. The center distance is adjusted to achieve the calculated preload. Too high a tension increases the bearing and cord load, while too low a tension can cause tooth jumps at load peaks.

How to identify the correct replacement belt

It is not enough to compare the total circumference of a belt. The correct replacement must have the same pitch, tooth profile and number of teeth as the existing drive. The width must match the pulleys and the required capacity, and a DL or GEN III version must be identified separately. If in doubt, pictures of the marking, tooth profile and pulleys can be used as a supplement, but a documented spare part designation is best.

Checking teeth, back and edges

Uniform light polishing of the tooth flanks may be normal, but localised spalling, ctiming baring or severe wear should be investigated. Wear on one edge often indicates misalignment or persistent flange contact. Damage to tooth tips may be due to incorrect profile, foreign bodies or inadequate engagement. If cord becomes visible or the belt has a sharp break, it should not continue in service without assessment.

Operating environment and maintenance

Continental specifies a temperature range of up to +100 °C for the GEN III series. When operating close to the temperature limits, the drive must still be dimensioned according to the specific load and environmental conditions. The service life is not only affected by the material, but also by load peaks, bending, pulley size, alignment and surroundings. Keep the drive clean and do not remove deposits with sharp tools that could damage the teeth. If the belt is operating in chemically exposed areas, food environments, clean rooms or at extreme temperatures, a suitable special design should be considered.

Technical questions about the product

Conti Synchroflex AT20 GEN III 1100: can GEN III run on standard AT20 discs?

Continental states that the GEN III version can be used on standard timing belt pulleys for the corresponding AT20 profile. However, the pulleys must be in good condition and the drive must be dimensioned for the load you want to utilize.

Conti Synchroflex AT20 GEN III 1100: what does the pitch length of 1100 mm mean?

The pitch length is the nominal length measured in the belt cord line where the steel cord tension elements are located. It is not the same as a random outer circumference measurement. For this belt, 1100 mm pitch length corresponds to 55 teeth with a 20 mm tooth pitch.

Conti Synchroflex AT20 GEN III 1100: what temperature can the belt operate at?

The GEN III series is rated for temperatures up to +100°C. When operating close to the limit, load, cooling and environment must be assessed separately.

Conti Synchroflex AT20 GEN III 1100: how to check if the length is correct?

Count the teeth and check the pitch. 55 teeth times 20 mm gives 1100 mm pitch length. Then compare the profile and design with the marking or the machine's spare parts list. A measurement around the outside of the belt alone is not accurate enough.

Conti Synchroflex AT20 GEN III 1100: can the width be measured with a regular caliper?

Yes, the belt width can usually be measured directly on the flat back or between clean, undamaged edges. However, the width is only one part of the identification. The profile, pitch length, number of teeth and any DL or GEN III version must also be correct.

Conti Synchroflex AT20 GEN III 1100: how does preload affect operation?

Correct pretension keeps the teeth in stable engagement and reduces the risk of tooth jump. Too low a tension can cause impact and jump under load, while too high a tension increases the load on the cord, pulleys and bearings. The correct value must be determined based on the drive's dimensioning.

Conti Synchroflex AT20 GEN III 1100: are the standard widths the only possible widths?

The documented supplier widths for this size include 16, 20, 25, 32 and 50 mm. The product page may also show intermediate sizes as cut widths when they are within the allowed range. This does not change the tooth profile or length, but the price is calculated based on the base width.

Brief summary

The product brings together the specified AT20 GEN III profile and length on one side, so that the appropriate width can be selected without creating a separate item for each cut. The main technical data is 1100 mm pitch length and 55 teeth. If in doubt about load or pulley compatibility, the drive should be calculated before ordering the belt.