An interesting little job recently which I expect to see more frequently. Drum Brakes are returning to popularity because they the pads and mechanism are protected from the elements; mud, water and road grime. The name most often seen is “Sturmey Archer” and these are starting to appear of eBikes, too. Hub brakes are especially popular on sit up and beg, Dutch style commuter bikes. Despite these advantages, compared to disc or rim brakes there are disadvantages, the main one being puncture repair should you need to remove the wheel.
As you might have figured, drum brakes are integrated into the hub. Whereas car drums are hydraulic, bicycle drums are cable actuated, from a normal, handlebar mounted brake lever. So co remove a wheel the connecting cable and and additional torque bar needs to be removed.
Given a bit of though and some maintenance before time, it is possible to do a tube replacement this at the roadside (typically you’ll need the right sized small spanner and a screwdriver in your saddle bag) and, of course you can always pull the tube out and patch it without removing the tube at all, but having a workshop and bike stand available makes life easier – especially if things have seized over time.
If you’d like to know more about drum brakes, Sheldon Brown has a great article on the full functionality at www.sheldonbrown.com/drum-brakes.html so do check it out.