On every spin, members are required to bring the following:

Pump
Ensure it is suitable for your valve type. And, for the love of God (or whoever you believe in), try out the pump at home first. Many of them are useless, and discovering this fact is no good when you are 60 km from home.

Tube
At least one spare tube. If you have the space, a second tube is no harm. Ensure the valve type on your tube matches your pump.

Tyre levers
Ever try getting a tyre off with your bare hands? Or your teeth?

Money
A small of amount will do, for the coffee stop.

Phone
Very useful to coordinate groups, and essential in an emergency.

Lights
Members are obliged to use front and rear lights during evening rides. It is recommended that the rear light is also used during daytime winter spins.

Optional
If you have room, a small multitool may come in handy.