Conti Synchroflex T2 138

Conti Synchroflex T2 138 – dimensionally stable timing belt for positioning and power transmission

With 69 teeth spread over a pitch length of 138 mm, the Conti Synchroflex T2 138 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 2 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.

Key technical data

• Pitch length: 138 mm
• Number of teeth: 69
• Tooth profile: T2
• Tooth pitch: 2 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.

How tooth geometry works

The T-profile is the classic metric timing belt profile with trapezoidal teeth and is described as a standard profile according to DIN 7721. It is used for general synchronous drives, positioning tasks and solutions with significant bending. The simple and proven geometry of the profile makes it widely used, but it still needs to be matched with a T-disc with the same tooth pitch. AT, HTD and other profiles are not automatically interchangeable.

Cast polyurethane and steel cord

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.

The construction behind this variant

The standard version is selected when the supplier's article data does not specify GEN III or DL. This is an important product distinction, because different versions can share both profile and length. Therefore, on this product page, it is the standard version that is described. The belt width can be selected, but the basic construction and tooth geometry are not changed.

From basic width to desired width

This product line has been created with 6 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 6 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.

Areas of application

Continental cites precision mechanics, positioning drives, small synchronous mechanisms and compact machine 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.

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.

The discs are part of the overall solution

A belt of 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 T2, the nominal tooth pitch is 2 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

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.

What does belt wear indicate?

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.

Environmental impact and ongoing monitoring

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.

Answers to typical questions

Conti Synchroflex T2 138: are the standard widths the only possible widths?

The documented supplier widths for this size include 6 and 10 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 T2 138: 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 138: 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 T2 138: 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 T2 138: why is the number of teeth important for spare parts?

The number of teeth links the pitch of the profile to the nominal length of the belt. For this size, 69 teeth at 2 mm pitch gives a length of 138 mm. It is a simple check that often reveals faults that are not visible by a quick comparison of two loose belts.

Conti Synchroflex T2 138: can the width be measured with a regular caliper?

Yes, the belt width can usually be measured directly on the flat back or between clean, undamaged edges. However, the width is only one part of the identification. The profile, pitch length, number of teeth and any DL or GEN III version must also be correct.

Conti Synchroflex T2 138: what does the pitch length of 138 mm mean?

The pitch length is the nominal length measured in the belt cord line where the steel cord tension elements are located. It is not the same as a random outside circumference measurement. For this belt, 138 mm pitch length corresponds to 69 teeth with a 2 mm tooth pitch.

Conti Synchroflex T2 138: why is 6 mm chosen as the basic width?

6 mm is the width of the supplier item whose SKU is used as the main product's stock reference. Other widths are handled as choices under the same product because they are cut from the same type of timing belt sleeve. The base width also determines the percentage-based pricing in the webshop.

The product in brief

The product brings together the specified T2 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 138 mm pitch length and 69 teeth. If in doubt about load or pulley compatibility, the drive should be calculated before ordering the belt.