The knocking could be from loose brake pads, loose wheel nuts, tie rod ends, or ball joints. Depending on the severity of the "knock" ( Pads usually "clack") If the knock is from the back the same applies (kinda)
Worn Ball Joint
one possible cause is struts can be weak causing tire to hop up and down when hitting a bump in the road!! And also tire could be out of balance.
When you hit the bump and you have the brakes applied, the tire will lock up when the tire is air-born for a moment.
A bubble on a tire is caused by damage to the tire. It looks like a bump on the tire and should be replaced.
What would cause a grinding noise after a tire is replaced and the brakes are not worn?
Your rear tire could be making a knocking sound for a number of reasons. You could have a damaged strut or axle that needs replacing.?æ
Tie rod
Tire out of balance is the most common cause.
Because it just does. That's why.
you could have a wire broke in the tire
Failed steering stabilizer shock, loose tie rod, bent steering component, slipped belt in a tire, etc.
more common is when a steel belt on one of the front tires has broken that then makes a little bump on the servace of the tire. run you hand over the surface of the tire and you will find a bump. that will be the bad tire. General Tire is known for that problem form what Ive seen. it could also be a loose balljoint, this could be very dangerous depending on how bad it is, you can lose a wheel causing you to lose control of your vehicle. Or it could just need a wheel alinement or a wheel balance.