The frame is sturdy, forming an upright, comfortable seat. Good visibility and awareness of potential obstacles when driving. The high centre of gravity makes it easy to carry loads without compromising the manoeuvrability of the bike.
Material - aluminium, the most common. Lighter than steel and stronger than carbon fibre. Used in all types of bicycles. It has the best value for money.
Large wheels, usually 28", so you'll have to pedal less and enjoy more of the ride.
Medium width tyres with low tread. They are narrower (and therefore faster) than mountain bike tyres and more durable than road tyres. Often with puncture protection.
The chainring is usually fully concealed under the chain guard for greater protection against dirt, staining and "dragging" of clothing when passing. The chain guard makes it less likely to need lubrication and the more common internal gears also make it more durable.
Long mudguards that cover the wheels well, so you can ride in all weathers without fear of getting dirty. Often made of metal for durability, while maintaining a classic design.
The saddle is wide, soft, often with extra cushioning - for the most comfortable ride possible.
Internal gears - the least maintenance.
V-brake brakes - easy to replace, lightweight, inexpensive, but selecting brake pads to suit the conditions of use can give high performance.
Lights connected to the dynamo - generating light as you go, without the need for additional lighting and battery.