Why does the crank on our woom 2 and woom 3 bikes rotate together with the freewheel?

If you rest your woom 2 or woom 3 on a bike stand ready for maintenance or stand it on its saddle and handlebars and turn the rear wheel with the crank, you may find that the crank rotates with the rear wheel once you have released it. It may also be the case that the crank rotates when the wheel is pushed. This is because there is less friction in the bottom bracket than in the freewheel. As a result, the rear wheel moves the chain via the friction in the freewheel, causing the free-moving crank to start moving too. Don't worry, though, as the force of the friction tends to be minimal anyway. You wouldn't even be able to see this effect if the bottom bracket didn't run so smoothly.