Hello! I have an Abu Garcia Revo STX-30 spinning reel and I was wondering if somebody could help me find the correct size bearings I’d need for replacement? The stock bearings keep getting grease intrusion and slowing up the reel.
 There is one under the reduction gear, one on the pinion, two on the drive gear. I don’t remember if there’s one in the oscillation gear and there’s a plastic bearing holder at the top of the pinion that has one too. Or even if there’s a set of every bearing in the reel. As long as they’re sealed I don’t mind if they’re not ceramic. I disassembled the entire reel, degreased everything. Oil in the bearings, grease on the gears. I believe the reduction gear bearing is the one that really needs the replacing but the two on the drive gear and one on the pinion would probably help a ton too.

What do you mean by a spinning reel being slowed down? What is grease intrusion on bearings that are often grease packed? If you want a more free feeling, just flush the bearings and oil them with Tsi321. I lube them in a bath of 80w140 gear oil as a compromise between light oil and grease packed. I don’t think changing the bearings will give you what you’re looking for. 

I agree with DVT, but if you really want to know each bearing size and change them, a cheap digital caliper would do the job perfectly.

measure inside id then outside od then thickness in that order.good micrometers help.