Conti Synchroflex AT10 840

Conti Synchroflex AT10 840 – precise PU timing belt for synchronous power transmission

With 84 teeth distributed over a pitch length of 840 mm, the Conti Synchroflex AT10 840 is designed for precise transmission of rotation, timing and position. The belt is cast endlessly in PU and has integrated steel cord tension elements that stabilize the length during normal operation. The nominal tooth pitch is 10 mm and the tooth profile must match the profile of the pulleys exactly. It is not sufficient for another belt to have approximately the same length or width. This is the standard version in the specified profile. It must not be confused with a possible GEN III version or a double-sided DL belt with the same pitch length.

Product data and fixed targets

• Pitch length: 840 mm
• Number of teeth: 84
• Tooth profile: AT10
• Tooth pitch: 10 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.

How tooth geometry works

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.

How the Conti Synchroflex belt is constructed

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.

Standard, GEN III or DL ​​– this version

This item is a single-sided standard design. The teeth are located on the inside of the belt, while the back is smooth. It should not be confused with a double-sided DL version or the red GEN III series. If the machine is originally dimensioned for a specific variant, a change should only be made after a technical assessment of load, pulleys and preload.

Areas of application

Continental cites construction machinery, pu , paper machines, compressors, compactors, textile machines and roller conveyor drives as examples for this profile family. The examples describe the profile's general area of ​​application, but do not constitute an approval for any specific installation. The final belt width and pretension must be selected based on the transmitted torque, starting and shock loads, operating time, pulley sizes, speed and the number of teeth in simultaneous engagement. For safety-critical or heavily loaded drives, an actual calculation should be made.

The discs are part of the overall solution

The pulleys and belt should be considered as a single tooth engagement. Correct AT10 geometry ensures that the load is distributed over 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 84 teeth and 840 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.

From basic width to desired width

The basic price applies to 16 mm, and the other widths are calculated with the same percentage logic as the existing PU timing belts in the webshop. Integer widths from 16 to 50 mm can be selected on this product page. A width of twice the basic width therefore costs 100% more, while a width of one and a half times the basic width gives approximately a 50% surcharge. This price rule is a webshop calculation; it does not replace a technical dimensioning of the belt's load-bearing capacity.

Wear patterns and troubleshooting

Early damage is often caused by conditions surrounding the belt rather than the material itself. Bent shafts, worn tooth grooves, foreign objects and incorrect pretensioning can all shorten the service life. In the event of a belt break, the pulleys should therefore be cleaned and inspected before the new belt is fitted. Also check whether load conditions or start-stop cycles have changed since the original design.

Operating environment and maintenance

The standard material is specified for ambient temperatures from -30 °C to +80 °C. Applications close to the limits, especially below -10 °C or above +50 °C, may require special sizing. The molded 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 may indicate misalignment, too low tension or worn pulleys.

Compare with the existing belt

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.

Technical questions about the product

Conti Synchroflex AT10 840: 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.

Conti Synchroflex AT10 840: 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.

Conti Synchroflex AT10 840: 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 AT10 840: can AT10 be used on a different tooth profile with the same pitch?

No, not without documented compatibility. The 10 mm tooth pitch describes the distance between the teeth, but the shape and clearance of the tooth flanks may differ. The belt must be used with pulleys manufactured to the AT10 profile. Visual similarity is not sufficient documentation.

Conti Synchroflex AT10 840: what does the steel cord mean for the function of the belt?

The steel cord tension members absorb the longitudinal tensile load and provide high longitudinal stiffness. This helps maintain pitch and position during operation. The cord must not be kinked, exposed or damaged during installation, as local damage can weaken the belt.

Conti Synchroflex AT10 840: 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 AT10 840: why can a timing belt make noise?

Noise can be caused by incorrect pretension, skewed pulleys, poor tooth profile compatibility, excessive speed, resonance or worn tooth grooves. Lubrication is not the solution. First check alignment, tension, pulley condition and whether the belt runs without abnormal side contact.

Conti Synchroflex AT10 840: can the belt be shortened or assembled to a different length?

No. This is a cast endless timing belt with a fixed pitch length. It can be cut to width within the available options, but the circumference and number of teeth cannot be changed. If the length needs to be changed, a different cast belt size is required.

Brief summary

In summary, this is a Conti Synchroflex PU timing belt with a fixed geometry of 10 mm pitch, 84 teeth and 840 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.