Second Hand Tandem Bikes

Obviously, the frame of a used tandem bike has to be appropriate for both riders. This is the most important consideration. Once you've got the hang of mounting and pedalling the tandem bike together, gears and braking are the next two important features of second hand tandem bikes to bear in mind.
In essence, the process of gear changing is no different on a tandem bike than with a solo bike. However, because much more power is running through the drive train (as there are two people pedalling), changing gear over the front rings needs a fair amount of skill and finesse. Too much pressure, and the chain can snap, come off - or at the very least, a tooth on the chain ring can be damaged. Therefore, the two riders need to be in sync and the rider to the back of the tandem needs to direct the lead rider to ensure a smooth and trouble-free gear change. Changing gears over the rear cogs does not require as much coordination. Tandems that are fitted with Rohloff gears can be particularly useful as the changing of the gears occurs through the rear hub.
In terms of brakes, there are several different options available on second hand tandem bikes. Cable pull disc brakes are easy to adjust and easy to replace. They are also beneficial as disc brakes don't create heat on the rims. They can be fitted on the rear of a tandem bike which creates a lot of braking power. They can also be fitted at the front.
Older used tandem bikes may come with drag brakes. They are great for reducing speed but are not as powerful as modern disc brakes.
Hydraulic brakes are a staple of mountain bikes can also be found on some second hand tandem bikes. They offer control and a greater amount of sensitivity and are very powerful too.