Conti Synchroflex AT20 GEN III 1260

Conti Synchroflex AT20 GEN III 1260 – durable PU timing belt with stable tooth pitch

This AT20 GEN III timing belt is specified with a pitch length of 1260 mm and 63 teeth. The ratio between length and number of teeth is fixed: 1260 mm divided by 20 mm gives exactly 63 teeth. The Conti Synchroflex AT20 GEN III 1260 is supplied as a cast, endless PU belt, so that there is no weld joint in the finished ring. The design is developed for synchronous operation and precise machine movements. The GEN III version is the reinforced high-performance design 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.

The most important product data

• Pitch length: 1260 mm
• Number of teeth: 63
• Tooth profile: AT20 GEN III
• Tooth pitch: 20 mm
• Material: cast polyurethane with steel cord
• Brand: Conti Synchroflex

These specifications can be used as a check against the marking on the old belt or against the machine's spare parts list. The pitch length is not necessarily the same as a measurement across the outside of the belt, and the number of teeth is therefore often the safest additional check. If in doubt, both the belt and timing belt pulleys should be examined before ordering a replacement.

What characterizes the AT20 GEN III profile?

In a synchronous belt drive, the movement is transmitted through the tooth flanks. The geometry of the AT profile is therefore crucial for both load distribution, noise level and position accuracy. A correct AT pulley supports the teeth according to the profile to which they are cast. If the pulley's tooth shape or pitch deviates, the load can be concentrated at a few pu and cause abnormal wear, even though the belt can apparently be mounted.

Materials and endless manufacturing

Conti Synchroflex is manufactured by casting, where the polyurethane is precisely shaped to the tool's tooth geometry around the embedded steel cord tension elements. The casting process provides high pitch accuracy over the entire circumference of the belt and a strong connection between PU and cord. The finished timing belt is endless and therefore has no welded joints. The polyurethane provides a wear-resistant tooth and back surface, while the steel cord takes the longitudinal tensile load.

What does the version designation mean?

In the GEN III series, both the polyurethane and the tension body are optimized for higher performance. The tighter cord packing can increase the permissible tensile load, and the balanced two-filament construction is designed to reduce flange friction and improve belt running. Continental states that existing standard AT or ATP pulleys can be used with the corresponding GEN III profile. However, the remaining dimensioning of the drive still needs to be checked.

Profile and length must match

When replacing a spare part, the marking on the existing belt should be compared with the product name. Check the profile designation, pitch length, number of teeth, design and width. If the text on the belt has worn away, the number of teeth can be counted and the pitch can be assessed by measuring over several teeth. A single external length measurement is less reliable because the nominal length of the timing belt is indicated in the pitch line.

Relevant machine tasks

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.

Choosing belt width

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.

Selection of discs for the profile

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.

Pre-tensioning and disc alignment

Proper installation begins with clean, undamaged pulleys with the correct profile. Teeth and grooves should be checked for deposits, bars and wear before the new belt is fitted. The pretension should be based on the drive's calculation and should not be selected based on a random hand feel. After the initial run-in, it is a good idea to check grooveing, noise, temperature and whether the belt runs centrally.

Maintenance-free does not mean control-free

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 timing belt operates without lubrication, and oil or grease should therefore not be added to dampen noise. The polyurethane is described as resistant to aging as well as simple oils, grease and petrol and to certain acids and bases. In the case of permanent contact, cleaning chemicals or unknown media, material compatibility should be specifically clarified.

Prevention of early belt damage

A properly running timing belt should move smoothly without continuous contact against one flange. Regularly check the teeth for deformation, the back for ctiming bars and the edges for frayed areas. Abnormal noise or heat can be an early sign of incorrect tension or pulley failure. A systematic check of pulleys and belt is more effective than trying to hide symptoms with lubricant.

Technical questions about the product

Conti Synchroflex AT20 GEN III 1260: is the polyurethane oil and chemical resistant?

The standard PU is described as resistant to simple oils, grease and petrol as well as certain acids and bases. This does not mean universal chemical resistance. In the case of continuous contact, high concentrations or cleaning agents, the specific liquid, temperature and exposure time should be assessed.

Is the Conti Synchroflex AT20 GEN III 1260 welded?

No. The Conti Synchroflex series is manufactured as cast, endless timing belts. The belt therefore does not have a welded joint around the circumference. The cast process provides a uniform tooth pitch around the entire belt and a strong bond between the polyurethane and the cast steel cord tension elements.

Conti Synchroflex AT20 GEN III 1260: 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.

Conti Synchroflex AT20 GEN III 1260: what should be checked after the first run-in?

Check that the belt runs centrally, that there is no abnormal heat or noise, and that the edges are not constantly rubbing against the flanges. Also look for signs of too low or too high pretension. If the drive requires a re-tension check, the machine manufacturer's procedure must be followed.

Conti Synchroflex AT20 GEN III 1260: what is the difference between tooth pitch and pitch length?

The tooth pitch is the distance from one tooth to the next and is 20 mm for this profile. The pitch length is the entire nominal circumference in the cord line and is 1260 mm. When the pitch length is divided by the tooth pitch, the belt has 63 teeth.

Conti Synchroflex AT20 GEN III 1260: can the belt be used for precise positioning?

The tooth engagement provides a positive, synchronous transmission without the normal slippage of a friction belt. This makes the profile relevant for positioning tasks, but the achievable accuracy also depends on the quality of the pulleys, shaft play, belt pretension, load and the overall machine design.

Conti Synchroflex AT20 GEN III 1260: what happens if the discs are not aligned?

Misalignment can cause the belt to wander towards a flange, causing edge pressure, heat and wear damage. It can also affect tooth engagement and reduce service life. Check both the parallelism of the shafts and the alignment of the pulleys.

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 1260 mm pitch length and 63 teeth. In case of doubt about load or pulley compatibility, the drive should be calculated before ordering the belt.