Conti Synchroflex T2.5 305

Conti Synchroflex T2.5 305 – endless metric timing belt for synchronous drives

Conti Synchroflex T2.5 305 is an endless, cast polyurethane timing belt with 122 teeth, 2.5 mm tooth pitch and a pitch length of 305 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's cord line and is therefore the measurement that must be compared with the existing belt, the machine's spare part data and the installed timing belt pulleys. 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.

Dimensions, profile and number of teeth

• Pitch length: 305 mm
• Number of teeth: 122
• Tooth profile: T2.5
• Tooth pitch: 2.5 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

As a classic metric profile, the T-series is used in many machines where reliable synchronous movement is important. The tooth shape is trapezoidal, and the number in the profile designation indicates the tooth pitch in millimeters. The correct washer must therefore both have the same pitch and be manufactured for the T-profile. The wrong profile can lead to poor engagement, noise and rapid wear.

Materials and endless manufacturing

The belt body consists of wear-resistant polyurethane, which encloses high-strength steel cord. The materials each have their own function: PU forms the teeth and protects the belt against mechanical wear, while the cord tensioning elements provide high longitudinal stiffness and limit post-elongation. Continental describes the design as maintenance-friendly and lubrication-free. This does not mean that the drive can be ignored; pulleys, alignment and pretension should still be checked.

The execution must be correctly identified

The product is the regular Conti Synchroflex standard version in the specified profile. Standard and GEN III may have the same pitch length and number of teeth, but they are different product series with different material construction and capacity data. The same applies to a DL belt, which has teeth on both sides. When reordering, the entire profile designation should therefore be checked, not just the length.

Areas of application

Continental cites precision mechanics, positioning drives, small synchronous machine movements and measuring and control equipment 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 belt width is selected on the product page

The basic price applies to 4 mm, and the other widths are calculated with the same percentage logic as the existing PU timing belts in the webshop. Integer widths from 4 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 50% extra. This price rule is a webshop calculation; it does not replace a technical dimensioning of the belt's load-bearing capacity.

Selection of discs for the profile

The tooth profile of the timing belt pulleys must correspond to the T2.5 of the belt, and their pitch must be 2.5 mm. The transmission ratio is determined by the ratio of the number of teeth of the pulleys, not by the width of the belt. A larger pulley usually reduces the bending load, while a very small pulley gives more bending per revolution. The angle of engagement and the number of teeth in mesh must be sufficient for the current load.

Splice, alignment and pre-tensioning

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.

Before ordering a replacement

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.

What does belt wear indicate?

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.

Temperature, media and service

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 service life is not only affected by the material, but also by load peaks, bending, pulley size, alignment and environment. Keep the drive clean and do not remove deposits with sharp tools that could damage the teeth. If the belt operates 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 T2.5 305: 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 305 mm and the same number of teeth of 122. 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 T2.5 305: what temperature can the belt work at?

The standard version is specified for ambient temperatures from -30 °C to +80 °C. At temperatures below -10 °C or above +50 °C, adapted sizing may be required.

Conti Synchroflex T2.5 305: can T2.5 be used on another tooth profile with the same pitch?

No, not without documented compatibility. The 2.5 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 T2.5 profile. Visual similarity is not sufficient documentation.

Conti Synchroflex T2.5 305: 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 T2.5 305: when should the timing belt pulleys be replaced?

Pulleys should be evaluated if the tooth grooves are worn, sharp, crooked or damaged. A new belt on worn pulleys may have poor load distribution and short life. Also check flanges for bars and side contact and the grooves for foreign objects.

Conti Synchroflex T2.5 305: 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 T2.5 305: 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.

Conclusion

Conti Synchroflex T2.5 305 is the correct size when the drive requires T2.5, 305 mm pitch length and 122 teeth. The belt is cast endless in PU with steel cord and must be used with timing belt pulleys that match the profile. Choose the width according to the technical load and always check the design, alignment and pretension before commissioning.