Is there a difference in the tendency of the wheels to lock?

You answered correctly. On most vehicles, especially motorcycles and bicycles, the rear wheel tends to lock before the front wheel when braking. This is because when you brake, the weight of the vehicle shifts forward, increasing the load and grip on the front wheel while reducing it on the rear wheel. With less weight on the rear, it reaches its grip limit sooner and is more likely to lock up if you brake too hard. Understanding this helps you apply the right braking force to each wheel for maximum safety and control.