One of the most important tools every cyclist should have at home is a torque wrench. Mid to top-end bikes and components today are generally made of carbon fiber. These carbon fiber components will need more attention and care during installation.
Too tight, and you risk breaking it. Too loose, and it could malfunction.
Tools required :
- Torque wrench
- Hex or Torx bits (size depends on the bolt)
- Allen keys
Estimated time : 1 minute
Step 1. Check the required torque value
- The spec varies depending on the material type, size, brand, and function.
- It’s usually printed next to where the bolt is. Otherwise, check the user manual.
Step 2. Have the right torque wrench
- Depending on your needs, you’ll need a smaller (2 to 16Nm), or larger (10 to 60Nm) torque wrench.
- Large torque wrenches are longer to allow for more leverage and can use a higher torque setting.
- It’s not recommended to use a torque wrench that can cover a wide range of torque values due to their lower accuracy.
Step 3. Prepare the torque wrench
- Insert the hex bits into the torque wrench.
- The most common hex bits are 4, 5, 6, and T25 for the smaller bolts. For others such as bottom brackets and cassette lockring, you’ll need the dedicated bits.
- Set the torque wrench to your desired torque value.
Step 4. Tighten the bolt
- Use your regular hex keys to tighten the bolts until they’re finger-tight.
- We’ll then use the torque wrench to further tighten it to the correct torque values.
- Depending on the model, some have a reversible ratchet system that goes both ways (clockwise and counterclockwise). Make sure to have it set clockwise to tighten.
- Some such as the Effetto Mariposa Giustaforza has an arrow indicating the tightening direction. This is useful for situations where the bolts are in awkward positions.
Step 5. Stop when you hear/feel the click
- The click sound/feel indicates that you’ve reached your desired torque value.
- Give it another slight push. You’ll hear/feel the click immediately and the bolt won’t tighten anymore.
- Reset the torque wrench to its default value (0Nm). This will help maintain its accuracy by reducing the stress on its inner components.
Important things to know
- Stick to the recommended torque values. You risk breaking the components if you exceed the value. The components would malfunction if you torque it below the recommended values.
- Use a torque wrench for carbon fiber components. While strong and light, carbon can easily crack if you apply too much pressure.
- Never drop the torque wrench. You risk damaging the internal components upon impact which will affect the accuracy.
Common torque settings for bicycle components
The table below shows the commonly used torque values for various bicycle components. Always double-check the user manual for the correct torque values of your bicycle components.
|Stem, seatpost||4 – 6Nm|
|Saddle clamp||8 – 12Nm|
|Lights, computer mounts||2 – 4Nm|
|Bottle cages||1 -2Nm|
|Bottom bracket, crankarms||30 – 40Nm|
Alex Lee is the founder and editor-at-large of Mr. Mamil. Coming from a professional engineering background, he breaks down technical cycling nuances into an easy-to-understand and digestible format here.
He has been riding road bikes actively for the past 12 years and started racing competitively in the senior category during the summer recently.