Niels, only the smaller and cheaper line-trimmers (such as Ryobi for example) have cantilevered crankshafts. The serious machines sold under major brands have two main bearings. Cantilevered crankshaft machines are commonly called "half crank" and machines with two main bearings are known as "full crank". I have not seen a half crank machine larger than 31 cc displacement.
You can usually recognise whether a trimmer or other small garden machine is full or half crank just by observing where the pull-start is located. If it is a full crank machine the starter is usually the topmost part of the machine, right on the top end of the engine. For a half crank machine the starter is necessarily at the other end of the engine, just above the clutch (if it has one) or the top of the drive shaft. This is because the half crank machine does not have a crankshaft at the top of the engine to attach the starter to: both flywheel and starter have to be on the bottom of the engine, and the bottom of the engine has to be adjacent to the top of the drive shaft.
