Shimano GRX Di2#
Electronic gravel groupset installed on the Canyon Grizl CF 8 Di2 as a 1×12 mixed configuration: GRX controls and crankset paired with Shimano XT derailleur and cassette for maximum gear range. See Shimano Di2 for platform details.
System Overview#
GRX is Shimano’s gravel-specific groupset line. The Di2 variant replaces mechanical cables with motors and electronics — shift buttons send signals to battery-powered derailleurs that move the chain precisely with no cable stretch or adjustment drift.
The Grizl CF 8 Di2 uses a mixed GRX/XT configuration:
- GRX: levers (ST-RX825), crankset (FC-RX820) — gravel-optimised ergonomics
- XT: rear derailleur (RD-M8250), cassette (CS-M8200) — wider MTB gear range
Installed Configuration#
| Component | Model | Spec |
|---|---|---|
| Shift/brake levers | Shimano GRX Di2 ST-RX825 | 1× hydraulic integrated, 2-piston, 389 g |
| Rear derailleur | Shimano Deore XT Di2 RD-M8250-GS | Medium cage, Shadow RD+ clutch, 450 g |
| Crankset | Shimano GRX FC-RX820 | 40T narrow-wide chainring |
| Cassette | Shimano Deore XT CS-M8200-12 | 9–45T, 12-speed |
| Chain | Shimano XT | 12-speed |
| Bottom bracket | Shimano Pressfit BB72 | PF 86.5 mm, 65 g |
| Battery | Shimano BT-DN320 | Internal, frame-mounted |
| Rotors | Shimano Deore XT MT800 | 160 mm, 170 g |
Gear Range#
| Sprocket | Ratio | Terrain |
|---|---|---|
| 40 × 10 (top) | 4.00:1 | Flat / descending |
| 40 × 12 | 3.33:1 | Road / fast gravel |
| 40 × 14 | 2.86:1 | Rolling terrain |
| 40 × 16 | 2.50:1 | — |
| 40 × 18 | 2.22:1 | — |
| 40 × 21 | 1.90:1 | — |
| 40 × 24 | 1.67:1 | Moderate climbs |
| 40 × 28 | 1.43:1 | — |
| 40 × 33 | 1.21:1 | Steep climbs |
| 40 × 39 | 1.03:1 | Very steep |
| 40 × 45 (bottom) | 0.89:1 | Maximum climb |
Di2 Electronics#
| Attribute | Spec |
|---|---|
| Connectivity | ANT+ (D-Fly wireless), E-TUBE wired |
| Head unit pairing | Garmin Edge MTB via ANT+ |
| Data transmitted | Gear position, battery level, shift count |
| Battery | Shimano BT-DN320 (internal, USB-C charging) |
| Customisation | E-TUBE Project app (button remapping, shift timing) |
The D-Fly module broadcasts gear data over ANT+ — the Garmin Edge MTB displays current gear and Di2 battery status natively and logs both to the .fit file.
XT Rear Derailleur — Shadow RD+#
The RD-M8250-GS includes Shimano’s Shadow RD+ clutch mechanism:
- Adds friction to the parallelogram to prevent chain slap and dropped chains on rough terrain
- Engaged via a toggle on the derailleur body
- Essential for off-road riding with a 1× system (no front derailleur to catch a dropped chain)
- Medium cage supports the 10–45T cassette range
Shifting Behaviour#
- Buttons: Multi-function satellite buttons can be remapped via E-TUBE Project
- Synchro Shift: Not applicable (1× system)
- Auto Trim: N/A (no front derailleur)
- Junction Box: A2 junction connects levers to derailleur; also provides charging port and head unit data port