First of all, breaks, chaincases and chainrings are the most in need of grease. Likewise, the rear suspension system demands proper greasing. Besides, the MTB chains can also be greased or lubed. The brakes, stair axles and rim ribbons also need greasing and oiling for proper functioning. However, it is recommended to avoid using spray lubricants, especially on the chains link. Such types can easily contaminate other parts of the bike. Instead, look for professional advice on the best lubricants for different parts of your bike.