You throw slicks on a hybrid mountain bike (i use 1.5 width) and it’s a fast awesome machine, even on base models. First thing i did with my new bike was remove the wide tyres. The extra weight of suspension forks is pretty negligible these days(when i did messenger work in college i removed my suspension forks, barely noticed the difference). The mountain bikes you see guys riding are hybrids; downhill or cross country bikes are totally different. Agreed though: the roads in Chengdu are generally very good, and there are basically no hills, so fixed gear is fine…..