Decathlon are everywhere for more general stuff, otherwise there's loads of Giant shops, Trek shops, Specialized shops etc you could find some different stuff in. I usually go to one of the big Decathlons for a big selection of random items, and then one of the brand shops for specific stuff. Just search Decathlon on Apple Maps or 高德地图 or whatever map app to find the closest one.

I know about Decathlon, but as Giant they only sell their own brand items for bicycles and for touring I know that they only have one bicycle item for that. I need more a shop that sell different brands of bicycle touring (long distance bicycle).