Conti Synchroflex AT5 GEN III 825

Conti Synchroflex AT5 GEN III 825 – durable PU timing belt with stable tooth pitch

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 AT5 GEN III 825 has the AT5 GEN III profile, 5 mm tooth pitch, 825 mm pitch length and 165 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.

Key technical data

• Pitch length: 825 mm
• Number of teeth: 165
• Tooth profile: AT5 GEN III
• Tooth pitch: 5 mm
• Material: cast polyurethane with steel cord
• Brand: Conti Synchroflex

The list gathers the information normally used to identify a timing belt: nominal length, number of teeth, profile, material and make. It is important to read all the information together. Two belts can have the same pitch length but be incompatible if the tooth profile or tooth pitch is different. Conversely, a different width does not change the number of teeth as long as the profile and pitch length are the same.

Why the correct profile is crucial

The AT profile has been further developed from the classic T profile. The larger tooth volume provides a higher tooth shear strength, and the profile is designed for a favorable tooth engagement with reduced engagement shocks. This makes the AT series suitable when a drive must be compact and at the same time transmit motion precisely. Continental states that the AT profile can perform up to 50% more than a corresponding T profile, but the actual capacity always depends on width, discs, speed and load profile.

How the Conti Synchroflex belt is constructed

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.

The execution must be correctly identified

GEN III is the reinforced high-performance version of the Conti Synchroflex series. The construction uses red high-performance polyurethane, more densely packed steel cord tension elements and a two-filament construction with balanced S and Z cords. Continental states up to 25% higher power transmission than the corresponding AT or ATP standard series. GEN III can use the standard profile timing belt pulleys, but the belt still needs to be dimensioned for the specific drive.

Where is this profile used?

The profile series is used in practice for tasks such as machine tools, pu , textile machines and positioning and conveying systems. 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.

Gear ratio, enclosure and tooth contact

The number of teeth on the pulleys affects both the gear ratio, deflection and how many belt teeth carry the load. A small pulley may be necessary in a compact drive, but it should not be selected without considering the minimum profile requirements and any counter deflection. Use timing belt pulleys with 5 mm pitch and the correct AT5 GEN III tooth shape, and check that the flanges do not damage the belt edge.

Pre-tensioning and disc alignment

The belt must be able to be placed on the pulleys without force. If it can only be mounted by forcing it over a flange, the center distance or mounting procedure is incorrect. The pulley shafts must be aligned and the flanges must be smooth and undamaged. In the case of multi-shaft or counter-bent drives, the diameter and position of the rollers must be assessed separately. Correct pretensioning reduces the risk of tooth skipping without unnecessarily loading the bearings.

How the width variants work

The belt width is not written in the product name because the same pitch length is collected on one product page. The starting pu is 6 mm. Integer widths from 6 to 50 mm can be selected on this product page. The original supplier widths for this length are 6, 8, 10, 12, 16, 20, 25, 32 and 50 mm. Other intermediate sizes are offered as cut-to-size versions of the same type of timing belt sleeve when they are within the selection shown. The number of teeth, pitch length and profile do not change when the width is changed.

What does belt wear indicate?

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 conditions of PU timing belt

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 cast PU belt is maintenance-friendly and does not require lubricant. Regular visual inspection is still relevant: look for ctiming bars, frayed edges, shiny tooth flanks, foreign body impressions and abnormal side contact. Sudden changes in noise or grooveing can be signs of misalignment, too low tension or worn pulleys.

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.

Practical questions before ordering

Conti Synchroflex AT5 GEN III 825: can a wider belt always transmit twice as much?

Not necessarily. A larger width provides a more active belt cross-section and can increase the permissible load, but the drive capacity also depends on the profile, number of teeth in mesh, pulley size, speed, load factor and preload. The width should be selected by an overall calculation.

Conti Synchroflex AT5 GEN III 825: what is the difference between tooth pitch and pitch length?

The tooth pitch is the distance from one tooth to the next and is 5 mm for this profile. The pitch length is the entire nominal circumference in the cord line and is 825 mm. When the pitch length is divided by the tooth pitch, the belt has 165 teeth.

Conti Synchroflex AT5 GEN III 825: can the belt be turned upside down on the pulleys?

The standard version is single-sided with teeth on the inside and a smooth back. It must run with the teeth in the corresponding tooth grooves; the back is not an alternative tooth side.

Conti Synchroflex AT5 GEN III 825: does this PU timing belt need to be lubricated?

No. The timing belt is designed for lubrication-free operation. Oil or grease should not be added to reduce noise as this may mask an alignment, pretension or worn pulley problem. Instead, keep the tooth mesh clean and check the cause of any abnormal noise.

Conti Synchroflex AT5 GEN III 825: can this belt be used at high rpm?

The Conti Synchroflex series is designed for precise and fast synchronous drives, but the permissible speed depends on the profile, pulley diameter, belt width, load and peripheral speed. A high speed must therefore not be approved based on the product name alone; the drive must be calculated.

Conti Synchroflex AT5 GEN III 825: what is the difference between AT5 GEN III and a GEN III belt?

This product is already GEN III. The reinforced version features high-performance PU and denser, two-filament steel cord construction and is a separate product line from the standard belt.

Conti Synchroflex AT5 GEN III 825: 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.

Summary

The product brings together the specified AT5 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 825 mm pitch length and 165 teeth. If in doubt about load or pulley compatibility, the drive should be calculated before ordering the belt.