The difference of ball and bearing system for Indoor Cycle pedals JD-304.
There are a steel ball and a bearing system for the indoor cycle pedal. The main difference between them is that the axis is different, As the picture showed,

The steel ball bearing pedal (JD-304), the shaft by punch machine with ball bearing extended cup, It’s more suitable for home (household) use or light commercial bike with low frequency.
For the sealed bearing pedal (JD-304V), the shaft by CNC machine with both side use sealed bearing, the precision and load-bearing capacity of the bearing system is much higher. normally for the commercial cycle use.
No matter what kind of system you use, we strongly recommend that you regularly maintain and replace it to extend the service life of the equipment.