The RISK RL255 Road 12-Speed Electronic Rear Derailleur Adjustment Gauge is a practical setup tool designed to help adjust the rear derailleur B-tension screw on compatible 12-speed road electronic shifting systems. It helps align the guide pulley position with the largest cassette sprocket, making derailleur setup more accurate and easier during bike assembly, drivetrain maintenance, or cassette replacement.
The RL255 uses a 2-in-1 reference design. One side is marked for compatible R7100 / R7150 / RX820 series rear derailleurs, and the other side is marked for compatible R8150 / R9250 series rear derailleurs. It includes reference markings for common cassette sprocket sizes such as 28T, 30T, 34T, and 36T, helping mechanics quickly find the correct adjustment position.
Made from lightweight polymer material using a 3D printing process, this gauge is compact, easy to carry, and suitable for workshop, store, and home mechanic use.
Note: This product includes the adjustment gauge only. Rear derailleur, cassette, bicycle, and other parts shown in images are for display only and are not included. 3D-printed products may have visible layer lines or seam marks; these are normal process characteristics and do not affect use.
| Item | Details |
|---|---|
| Brand | RISK |
| Model | RL255 |
| Product Name | Road Electronic Rear Derailleur Adjustment Gauge |
| Material | Polymer / Plastic |
| Color | Blue |
| Compatibility | Road 12-speed electronic rear derailleurs |
| Compatible Reference Series | R7100 / R7150 / RX820 / R8150 / R9250 etc. |
| Cassette Reference Markings | 28T / 30T / 34T / 36T |
| Product Size | Approx. 81 × 36 × 3.5 mm |
| Net Weight | 1 pc approx. 6.4 g; 2 pcs approx. 12.8 g |
| Packaging | RISK branded bag |
| Gross Weight | 1 pc approx. 7.8 g; 2 pcs approx. 14.2 g |
| Package Size | 1 pc: approx. 8 × 10 × 0.4 cm; 2 pcs: approx. 17 × 10 × 0.4 cm |
| Compatible Rear Derailleur Series | Cassette Reference Markings |
|---|---|
| R7100 / R7150 / RX820 etc. | 34T / 36T |
| R8150 / R9250 etc. | 28T / 30T / 34T |
Compatibility information is for reference only. Please confirm your rear derailleur and cassette specifications before purchase.
Quantity: 1 pc / bag
Color: Blue
Material: Polymer / Plastic
Net Weight: Approx. 6.4 g
Gross Weight: Approx. 7.8 g
Package Size: Approx. 8 × 10 × 0.4 cm
Use: Single tool for individual riders, home mechanics, and daily workshop use.
Quantity: 2 pcs / bag
Color: Blue
Material: Polymer / Plastic
Net Weight: Approx. 12.8 g
Gross Weight: Approx. 14.2 g
Package Size: Approx. 17 × 10 × 0.4 cm
Use: Backup set or shop/workshop pack for frequent maintenance.
Helps adjust the B-tension screw and guide pulley position for smoother drivetrain setup on compatible 12-speed road electronic systems.
One gauge supports multiple compatible derailleur series, including reference zones for R7100 / R7150 / RX820 and R8150 / R9250 series.
Printed reference lines for 28T, 30T, 34T, and 36T cassette sprockets make adjustment more intuitive.
Compact size and light polymer construction make it easy to carry in a toolbox or workshop drawer.
Useful for bike shops, mechanics, and riders who maintain or upgrade their own drivetrain.
Always refer to the original drivetrain manufacturer’s service manual for final setup specifications.
This product is made using a 3D printing process. Visible layer lines, seam marks, or slight surface texture are normal production characteristics and are not quality defects. These do not affect function or durability under normal use.
