Decathlon is known for its price-busting apparel, and the Rockriders are no exception. £20 gets you a pair of baggy shorts with two front-zippered pockets, some slightly stretchy front panels and a comfortable elasticised waist with drawstring, a key fob and reflective tags - though there's no gusseted crotch.
Overall quality is good and the material has a reassuringly durable feel. There's an integrated inner short with a basic but wide chamois, and well-positioned leg grippers. The shape isn't too baggy - they look like gym shorts. The only real downside is a loose cut at the front which balloons out a bit, and a lower cut at the back, which feels a bit like the shorts might be dropping down and exposing a builder's bum on the bike. Not ideal, so check the fit before you buy. The inseam is 11in.