Basket – metal or wicker – for handlebars
Bells
Bike wash (and refills) – cleans your bike. Refills, if you have already have a suitable container
Book – Park Big Blue Book of Tool and Repair, 3rd edition
Bottle cages – hold your water bottle on your bike frame
Bottom bracket – attaches the pedal arms (cranks) to the bottom of the bike frame.
Brush(es) – cleaning
Cable cutters – the industry-standard Park Tools cutters
Cable locks – not as secure as D-locks, but smaller, lighter
Cassettes (7spd up to 11spd)
Cassette lockring tool – required to remove a cassette
Chains (single-speed up to 11spd)
Chain cleaner spray – helps clean the mud and muck off your chain
Chain gauge – tells you if your chain is worn out
Chain whip – required to remove a cassette
D-locks – in a range of prices and security levels
F-K
Freewheel block – the older-style screw-on back gear cogs, before cassettes arrived
Freewheel remover – takes a freewheel off, surprisingly enough 🙂
Gaadi specialist inner tubes – fit one to avoid having to take wheel out of the frame to repair a puncture
Hand cleaner
Handlebar grips – help keep your hands where they belong
Helmets – adult sizes small to large, and some children’s helmets
Grease gun – helps you get the grease exactly where you want it
Inner tubes – in a wide range of sizes for a wide range of bike types
Lights – rechargeable (USB) and non-rechargeable LED lights across a range of prices
Lubricants dry and wet – oil for use in either dry or wet conditions
Nuts and bolts
Pedals – new and used, metal or plastic
Reflectors – a legal requirement but often missing from bikes
Road shift cable set – keep your gear change fast and reliable
Rucksacks – small backpacks for carrying food and drink (or a bit of shopping)
Seats – new and used, in a range of styles and sizes
Spanners – for all manners of bike jobs
Sprays – cans of the ever-popular GT85 and TF2 lightweight spray lubricants
Wheels – in a range of size, as either quick-release or bolt-on