These revised rollers for the Hydra Pro Mod work great but I found that the bolts that the bearing rides not being secure caused the bolt to shift and sometimes fall out when I relocated the position of the roller. I modified the roller to accept an M3 nut to secure the bolt to the bearing, making it attach securely to the roller. I also made the center of the roller solid since it no longer required a cavity for the bolt to sit inside, which should improve long-term durability.

Bill of Materials:

1. M3x6mm Hex Socket Head Cap Bolt/Screw (2 per roller)
2. M3 Nut (2 per roller)
3. 3x8x4mm Bearing (2 per roller)
4. Blue Threadlocker (optional but recommended) I prefer using a gel for easier application

Installation:

1. Insert bolt through the center of the bearing.
2. (OPTIONAL STEP) Thread nut on one turn and then use a toothpick or similar object to apply threadlocker on the open area of the M3 nut and wipe away the excess. It is important to apply the threadlocker using this method to avoid getting threadlocker on the bearing.
3. Tighten M3 nut onto M3 bolt
4. Use Allen Wrench to insert the bearing.
5. Check that the bolt spins freely. If not, use a pair of vise grips to remove the bearing assembly and check for any areas of interference.