What do Shimano's stated size-code letters mean?
These meanings come from Shimano Japan's 22 Stella official guide (checked 2026-10-13). The ranges summarize the 309 Shimano sizes in our Japanese tables; they are observations, not definitions of a code.
| Code | Shimano's meaning | Sizes here | Observed gear ratios | Observed spool diameters |
|---|---|---|---|---|
| C | Compact body | 84 | 5–6.4:1 | 42–54 mm |
| S | Shallow spool | 55 | 5–6.3:1 | 42–47 mm |
| SS | Super shallow spool | 1 | 4.4:1 | 40–40 mm |
| PG | Power gear | 22 | 4.4–5.1:1 | 38–94 mm |
| HG | High gear | 109 | 5.1–7.8:1 | 29–73 mm |
| XG | Extra high gear | 81 | 6.2–8.9:1 | 29–68.6 mm |
| M | Medium deep spool | 18 | 5.3–6.2:1 | 47–52 mm |
| DH | Double handle | 7 | 5–5.8:1 | 46.5–47 mm |
What do SHG, MHG, SDH and SSS show in these tables?
For these full strings, we report common features visible in the recorded model codes and measurements. We have not found a general Shimano definition for each entire string. SHG combines a shallow-spool code and HG; MHG combines M and HG; SDH combines S and DH. SSS is treated only as an observed code here.
| Code in size | Recorded sizes | Gear-ratio range | Weight range |
|---|---|---|---|
| SHG | 23 | 5.8–6.2:1 | 145–240 g |
| MHG | 15 | 5.7–5.8:1 | 170–275 g |
| SDH | 6 | 5–5.8:1 | 175–270 g |
| SSS | 3 | 4.4–5.1:1 | 140 g |
How do HG vs XG compare?
Shimano calls HG “high gear” and XG “extra high gear.” Across our Japanese tables, 109 HG-ending sizes span 5.1–7.8:1, while 81 XG-ending sizes span 6.2–8.9:1. These ranges overlap across series, so compare the two sizes within one series: Stella's full size table or Vanquish's table.