SP Takegawa 5-Speed Cross Transmission Kit – Honda Grom / MSX125 / Monkey 125
Unlock smoother acceleration and tighter gear spacing with the SP Takegawa 5-Speed Cross Transmission Kit. By adding a fifth gear and optimizing the gear ratios across the entire range, this kit keeps your engine in its power band longer — whether you’re running a stock motor or a full SP Takegawa big bore build. Short-stroke gear travel improves shift feel and increases durability, making this one of the most impactful drivetrain upgrades available for the Grom platform.
Features
- 5-Speed Cross Transmission – Adds a 5th gear and tightens ratio spacing for smoother, more efficient acceleration
- Short-Stroke Gear Travel – Secures tooth width and improves shift durability under hard use
- Compatible with Stock & Big Bore Engines – Works with OEM motors and SP Takegawa big bore kits without sacrificing torque output
- Includes Gaskets – L. Crankcase cover gasket and R. Crankcase gasket included in the kit
Gear Ratio Comparison
| Gear | Stock 4-Speed | Takegawa 5-Speed |
|---|---|---|
| 1st | 2.500 | 2.333 |
| 2nd | 1.550 | 1.684 |
| 3rd | 1.150 | 1.272 |
| 4th | 0.923 | 1.040 |
| 5th | — | 0.923 |
Compatibility
- Honda Grom (OG MSX125, SF MSX125SF)
- Honda Monkey 125 (1st Gen)
Important Notes
- Speedometer: The stock speedometer will not operate after installation unless a compatible speed sensor kit is installed simultaneously.
- Required Tools: Flywheel puller for Grom/MSX125 and a lock nut wrench rotor holder are required for transmission replacement.
- Instruction manual, if included, will be in Japanese.
- Product specifications subject to change by manufacturer.
