i was riding today and i noticed the wheels all have a little play in them. Im just wondering if this is normal to be a little loose. like when i pick it off the ground the two front tires feel like they have a little more play in them than the back. please tell me its normal and the wheels arnt gonna fall off. the lug nuts are all tight by the way. is there a way to tighten the tires up or is this normal? thanks