The relative abundance of heritage architecture and mixed zoning in the former French Concession neighborhood (technically the Xuhui district) has left a legacy of nooks and crannies where a number of mom-and-pop noodle shops are able to withstand the test of time and pressures of a fast-changing economy. Luckily, enough noodle lovers are still craving the classics and will queue up to support their favorite local haunts. Our top five picks can get crowded, but if you avoid the main lunch rush from noon to 1 p.m., you shouldn’t have to fight (too hard) for a seat.