Me and my bro decided to just get 15,m bearings and shim them.. Till he buys an alloy for the back wheel ten we will just change the china bearings for nsk ones so they don't jam and chew after a week of riding haha wheni was riding today my bike powered through 1st but after an hour and a haf it started going flat and quiet at the high end of 1st anyone have any ideas n why that's happening? Let it cool down alittkw ( 30 mins ) and it powered through 1st again no flat spots.. ?