I got a used Mongoose BMX for my son. I know when I was younger Mongoose was halfway decent. But now they kinda stink. Putting that lightly!
Anyway the bike rode well at first, then after a flat tire and innertube change he would start riding and the rear free wheel or sprocket would spin but not the rear tire so my son keeps wrecking the bike! I've tried adding some lube to it and that worked for about a minute!now same issue? What can I do? No extra noises or anything like that.