• Wind the wire from the power sensor to the chain speed sensor securely around the rear derailleur cables so that the wire is not hanging loosely, but it must be loose enough so it does not interfere with the normal operation. If you are installing the sensor on a mountain bike, it is not always necessary to wind the wire around the rear derailleur cable, as the wire may not be long enough.
  
  
• There are 3 pulley bolt options included in the package. Choose from the following table the most suitable pulley bolt to be installed on your bicycle. Please note that only some commonly used rear derailleur types are included in the table. The bolts are suitable for many other types as well.
  
  

If you have a SRAM derailleur, call our customer service department at 800-227-1314 for proper size bolt.

• Detach the original bolt from the rear derailleur. Install the chain speed sensor on the rear derailleur and fasten it with one of the bolts included. Do not fully tighten at this point.
  
  
• Check that all gears function properly and the chain sensor does not touch the spokes when the chain is on the biggest cog.
  
  
• Once positioned correctly, tighten the bolts securely.
  
  *Note: To ensure your safety, attach the wires of the power output sensor firmly to the frame of the bike using the zip ties. Be careful not to tighten the zip ties to tightly, to ensure they do not cut into the cables. You could also use electrical tape as a substitute for the zip ties.