The Shimano Saint RD-M820-SS is a 10-speed short-cage rear derailleur engineered for the brutality of downhill and freeride riding. With Shadow+ stabilisation technology and a low-profile skid plate, it eliminates chain slap and drop so you can stay focused on the trail ahead. A unique mode converter lets you switch between downhill and freeride configurations to suit your cassette setup.

Highlights

  • Shadow+ Stabilisation: Friction-controlled clutch mechanism suppresses chain bounce and slap, keeping the drivetrain quiet and the chain on the ring through rough terrain.
  • Mode Converter: Flip between DH mode (max 28T sprocket) and FR mode (max 36T sprocket) to suit your riding style and terrain.
  • Low-Profile Skid Plate: Protects the derailleur body from rock strikes and crash impacts — a must for gravity riding.
  • Silent Bump Stopper: Urethane vibration-absorbing piece dampens derailleur noise on rough terrain, reducing driver distraction.
  • Aluminium Cage: Both inner and outer cage plates are aluminium for a strong yet lightweight construction.
  • 1x10 Optimised: Designed specifically for 1x10 drivetrains, providing clean and reliable shifting without a front derailleur.

Built for Gravity Riding

The Saint M820 groupset was developed with one purpose: to handle the most aggressive riding conditions on earth. The RD-M820-SS short-cage derailleur is the centrepiece of that system — low-slung to avoid rock strikes, with a robust body that resists deformation even after a hard crash. Shadow+ technology originated in Shimano's cross-country and trail components but was tuned for downhill and enduro demands here, offering adjustable friction resistance so you can dial in exactly how much chain stabilisation you need.

Compatibility & Fit

The RD-M820-SS is a 10-speed derailleur compatible with Shimano MTB 10-speed shifters including SL-M820, SL-M7000-10, SL-M6000, SL-M4100, SL-M640, and SL-M610. In DH mode it accepts a maximum sprocket of 28T; in FR mode (with mode converter) it accepts up to 36T. Total capacity is 25T. Designed for use with Shimano HG-X 10-speed chains (CN-HG95, CN-HG54). Pulley teeth: 11. Uses a standard direct-mount or B-link hanger attachment.

Shimano offers a limited warranty covering defects in materials and workmanship. For warranty support, return the item to Tune Cycles.
  • Shadow+ friction clutch suppresses chain slap and drop on rough terrain
  • Mode converter enables switching between DH mode (max 28T) and FR mode (max 36T)
  • Low-profile skid plate protects derailleur body from rock strikes and crashes
  • Silent bump stopper with urethane damper reduces derailleur noise
  • Short cage design keeps the derailleur tucked for improved ground clearance
  • Aluminium inner and outer cage plates for strength and low weight
  • Compatible with Shimano 10-speed MTB shifters and HG-X chains
  • Engineered for 1x10 downhill and freeride drivetrains
Speed10-speed
Cage LengthShort (SS)
Total Capacity25T
Max Sprocket (DH Mode)28T
Max Sprocket (FR Mode)36T
Min Largest Sprocket23T
Weight280g
Pulley Teeth11T
Cage MaterialAluminium (inner and outer)
TechnologyShimano Shadow+
Drivetrain1x10
Compatible ShiftersSL-M820, SL-M7000-10, SL-M6000, SL-M4100, SL-M640, SL-M610
Compatible ChainsCN-HG95, CN-HG54 (HG-X 10-speed)
SeriesShimano Saint M820
Year2013
SKU SHM-IRDM820SS1
Barcode # 4524667299684
Brand Shimano
Shipping Weight 0.4600kg
Shipping Width 0.160m
Shipping Height 0.060m
Shipping Length 0.220m
Shipping Cubic 0.001000000m3
Unit Of Measure each
Must be installed and serviced by qualified bicycle mechanic