It depends on the quality of the motor (materials used, construction technique) and how many poles it has. The 35k rule that people refer to should be the 230/poles rule IMHO. If I were to (attempt to) run my 8 pole motor over 30k, it'd overheat very quickly (if my ESC can even drive it beyond 30k...)

I don't know how many poles the Feigao motors have. Neu 1500 has 4 poles, Neu 1900 has 8. Ideal motor for our cars would have 6 or 8 poles due to gearing limitations. (difficult to gear for motor RPMs over 40k)

Don't forget ESCs have RPM limits too. Most will handle 250-300k/pole, but some much less. (BK controllers?)