The length of the derailleur cage is often associated with the range of tooth sizes that it can accommodate on the rear cassette. Different cage lengths are designed to handle specific ranges of tooth sizes on the cassette. Here’s a general guideline for the cage length and the range of tooth sizes on the rear cassette:
- Short Cage (SS – Short Cage):
- Typically designed for cassettes with a smaller range of teeth, often in the range of 11-28 to 11-32 teeth.
- Suitable for 1x (single chainring) setups or 2x setups with smaller front chainrings and narrower cassettes.
- Short cages are commonly used in road cycling and cyclocross where a wide gear range is not necessary.
- Medium Cage (GS – Medium Cage):
- Designed to handle a moderate range of tooth sizes on the cassette.
- Suitable for 2x setups with larger front chainrings and cassettes with tooth ranges typically from 11-32 to 11-36 teeth.
- Often used on gravel bikes and all-road bikes where a balance between gear range and chain tension is needed.
- Long Cage (SGS – Long Cage):
- Designed to accommodate a wide range of tooth sizes on the cassette.
- Suitable for 2x and 3x setups with larger front chainrings and cassettes with larger tooth ranges, such as 11-42, 11-46, or even 10-51 teeth.
- Commonly found on mountain bikes where a broad gear range is essential for steep climbs and technical descents.
It’s important to note that these are general guidelines, and the specific compatibility may vary depending on the derailleur model and brand. Always check the manufacturer’s specifications and recommendations for your particular derailleur to ensure it is compatible with your cassette and drivetrain setup. Choosing the right derailleur cage length is crucial for proper shifting performance and to prevent issues like excessive chain slack or tension.
The specific length of a short cage derailleur can vary between manufacturers and models, but generally speaking, a short cage derailleur typically has a cage length of around 60-70mm (2.36-2.75 inches). Medium cage derailleur typically has a cage length of around 70-90mm (2.75-3.54 inches). Long cage derailleur typically has a cage length of around 90-110mm (3.54-4.33 inches). This length is measured from the center of the jockey wheel (the small pulley wheel) to the center of the mounting bolt that attaches the derailleur to the bike frame.
Short cage
Medium cage
Long cage