Modern bottom brackets use a sealed bearing type construction that keeps water and debris locked out, so they seldom go wrong. Maintenance is impossible so they need replacing when they do wear out. Older style cup bottom brackets need to be re-greased every now and again, and occasionally will need to have their bearings replaced. There are a lot more teeth on the chainring cogs than those on the rear cassette, so need changing less regularly. Cranks usually a solid one piece construction so there is not much to go wrong.
Many bikes, including older models and track bikes, have bolts attaching the wheels to the frame instead of quick-release levers. If your wheels are bolted on, in most cases you’ll need a 15 mm wrench to remove it. We didn’t test wrenches, because there aren’t that many tiny 15 mm wrenches, but the GearWrench 15mm 12-Point Stubby Combination Wrench is perfect for stuffing into a flat kit and Amazon reviewers seem to think the same. Our experts also recommended the Surly Jethro Tule, but it’s expensive and harder to find.
The retractable tube is stored inside the body of the pump when not in use, and it can attach to either a Schrader or a Presta valve, the two types of valves you’ll see. Some pumps can accommodate only one type, making them less universal. Toggling between the two is simple, which can’t be said of other models with itty parts that require nerves of steel to handle on a good day, let alone while wearing gloves, crouching in the wind, oblivious to the sewer grate a few feet away.
Broadly speaking there are two major wheel sizes – 700c for road bikes and 26 inch off-road wheels. However there are a whole variety of older, less common wheel sizes and of course fold up bikes have much smaller wheels altogether. Repairing a puncture is not an emergency! It’s a basic procedure that every cyclist should be able to to perform, but doing it correctly involves more steps than many people realise. Wheel building is often seen as the most artful skill in bicycle maintenance, and separates the professionals from the amateurs but that doesn’t mean you should consider it out of reach. Truing a slightly misaligned wheel is a cycle maintenance job that almost any cyclist can perform.