normally if u r not mechanic or specialist its hard to check it,just don buy those timing belt which from china,if others japan quality belt,the minimum can support 60,000km if original can go on 100,000km,but due to warm up ur ride n traffic jam,u have to minus about 10,000km n change it,coz at those situation ur engine still runing but ur meter wont show the mileage,orr others way,when u almost reach 50,000km then ask mechanic open the timing cover to c the belt condition :D