2016, none of the above worked for me until i explicity set the 'type' in addition to the 'limit' for bodyparser, example:
var app = express();
var jsonParser = bodyParser.json({limit:1024*1024*20, type:'application/json'});
var urlencodedParser = bodyParser.urlencoded({ extended:true,limit:1024*1024*20,type:'application/x-www-form-urlencoded' })
app.use(jsonParser);
app.use(urlencodedParser);