Decathlon are huge, very successful across Europe and getting that way in the UK too I think. They could do with making stronger bikes though but then maybe that is part of their price advantage, buying lighter weaker frames means the final weight of the bike can be competitive even if many of the components are low end. I've seen bike reviews where they have stated a preference for a btwin bike because its 1/2kg less than a competing bike of similar components but the rider weight capacity was over 35kg less. About 88kg vs 125kg. Even if I weighed 80kg I'd rather have the extra safety margin unless I was a really competitive cyclist.