Here are some common applications and uses of 20 inch hub motors on bikes:
Kids’ E-Bikes – A 20 inch wheel size is perfect for smaller kids’ bikes. Hub motors make electric conversion easy without needing a bulky bottom bracket motor.
Cruisers/Beach Cruisers – 20 inch wheels are standard on many casual cruiser style bikes. A rear hub motor can add a boost for cruising boardwalks or riding to the store.
Folding Bikes – Many compact folding bikes use 20 inch wheels. A small hub motor allows the bike to be folded up after commuting or traveling with electric assistance.
Cargo/Utility Bikes – 20 inch wheels are common on lightweight cargo bikes for carrying kids or goods. A hub motor helps with the extra weight.
Conversion Kits – Affordable e-bike conversion kits are available featuring a rear 20 inch wheel with an integrated geared hub motor and battery.
Trail/Hybrid Bikes – For relatively smooth off-road use, a 20 inch wheel with front suspension and a geared hub motor expands the capabilities of a casual trail bike.
Winter Biking – Studded tires paired with a hub motor provide electric assist through snowy conditions on a compact 20 inch bicycle.
Mini E-Bikes – Folding or compact “mini” e-bikes meant for limited space often use 20 inch wheels with hub motors.
So in summary, 20 inch hub motors are great for lightweight, compact electric bikes for kids, casual riding, cargo/utility uses, or winter conditions.