5065 Motor mount for Decathlon Longboard Fish 500

Functional prototype — good enough for use, but open for improvements by the community.

This prototype is designed for a 40T wheel pulley (based on JuniorPotato93’s 15 mm ASA version, with some modifications) and a 13T motor pulley, used with a 5M 270 mm belt (from Aliexpress, about 5 USD).

🔧 Assembly requires:

• 2 × M5 screws, 85 mm long (I cut them down from 100 mm ones)
• 4 × washers, up to ~19 mm outer diameter (20 mm space available)
• 2 × M5 nuts
• 4 × M4 screws, 10 mm long (to mount the 5065 motor)
  • ⚠️ If the screws are too long, the motor may be damaged!

💡 Tips:

• A hairdryer helps with a tight fit.
• If the belt keeps drifting to one side, slightly adjust the motor angle by tightening/loosening the screws until balanced.
• Removing the support base was tricky for me – I used a lighter to flatten it afterwards (not really a recommended solution).