Hello Robbi,
You need an special tool that fits in the big chainwheel. Turn the wheel so that you an see the two holes in the back of the wheel trough the front holes. Then you can turn it lose lift yhe wheel with the tool upwards to tighten the chain. The tool is like an wrench to change an disk fron an Angle grinder but the pens are longer. Succes
ransomes friend from holland
April 2009