Conti Synchroflex AT5 GEN III 255

Conti Synchroflex AT5 GEN III 255 – endless timing belt for precise industrial drives

Conti Synchroflex AT5 GEN III 255 is an endless, cast polyurethane timing belt with 51 teeth, 5 mm tooth pitch and a pitch length of 255 mm. It is intended for synchronous power transmission, where the driving and driven shafts must follow a fixed tooth ratio without the slippage known from friction-based belt drives. The pitch length is the nominal length measurement in the belt cord line and is therefore the measurement that must be compared with the existing belt, the machine's spare parts data and the installed timing belt pulleys. The GEN III version is the reinforced high-performance construction with red high-performance polyurethane and denser, two-filament steel cord. It should therefore be treated as a separate product series and not as the regular standard version.

Technical information for this timing belt

• Pitch length: 255 mm
• Number of teeth: 51
• Tooth profile: AT5 GEN III
• Tooth pitch: 5 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.

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.

Materials and endless manufacturing

The endless PU construction combines low dead weight with high longitudinal rigidity. The steel cord tension elements are cast into the belt and are not intended to be exposed, damaged or sharply broken during installation. The wear resistance of the polyurethane and the strong bond to the cord are central to the belt's lifespan. Correct handling is therefore just as important as the correct choice of profile and length.

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.

Which drives is the product compatible with?

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.

Environmental impact and ongoing monitoring

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.

Choosing belt width

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.

The discs are part of the overall solution

The pulleys and belt should be considered as a single tooth engagement. Proper AT5 GEN III geometry ensures that the load is distributed across the tooth flanks rather than concentrated on tooth tips or edges. The drive ratio is selected by the number of teeth on the pulleys, while the belt's 51 teeth and 255 mm pitch length determine the required combination of pulleys and center distance. When changing the drive, the geometry should be calculated.

Pre-tensioning and disc alignment

When installing, the cord pullers must be protected against kinks and local pressure damage. The belt must not be pinched with pliers or a screwdriver, and it should not be folded sharply. Check that the pulleys have the same pitch and profile as the belt and that they are not worn out. A stable drive is achieved through the right combination of alignment, wrapping and calculated pretension.

Wear patterns and troubleshooting

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.

Checking when replacing

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.

Questions and answers about this timing belt

How many teeth does the Conti Synchroflex AT5 GEN III 255 have?

The belt has 51 teeth. The number of teeth is calculated by dividing the pitch length of 255 mm by the tooth pitch of 5 mm. The result is 51, and this number can be used as an additional check when identifying an existing belt. A different number of teeth means a different pitch length.

Conti Synchroflex AT5 GEN III 255: 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 255: does the number of teeth change when the belt width is changed?

No. All width choices on this product page have the same pitch length of 255 mm and the same number of teeth of 51. Only the width of the belt, and thus the price and possible load capacity, changes. The width must still match the pulleys and the technical dimensioning.

Conti Synchroflex AT5 GEN III 255: 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 AT5 GEN III 255: why is GEN III not merged with the standard version?

GEN III has a different material construction and capacity data than the standard belt. The higher cord density, two-filament construction and high-performance polyurethane make it a separate product line, even though the pitch length and tooth profile may be identical.

Conti Synchroflex AT5 GEN III 255: can an old V-belt be directly replaced by this timing belt?

No. A timing belt requires timing belt pulleys with the correct profile and pitch, while a V-belt works by friction in V-grooves. A conversion therefore requires new pulleys and a dimensioning of the entire transmission. The product is intended as a timing belt, not as a universal replacement.

Conti Synchroflex AT5 GEN III 255: are the standard widths the only possible widths?

The documented supplier widths for this size include 6, 8, 10, 12, 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.

Summary

In summary, this is a Conti Synchroflex PU timing belt with a fixed geometry of 5 mm pitch, 51 teeth and 255 mm pitch length. The width is selected separately, but does not change the length or number of teeth. A safe replacement requires that the entire designation and the specific version match the machine documentation.