You guys should borrow a page from the heli side. After the OS 50 SX-H and Hyper got the reputation for eating metal retainers, a lot of bearing suppliers started selling bearings with plastic retainers. VOILA! Problems mostly went away. OS finally caught on and began installing them as OEM. Tey still have problems with the OEM bearings but at least some of them can get more than 5-7 gallons through without destroying their engines. I have several different sizes of rear bearings with plastic retainers and some with stainless steel races. For those engines, problem solved!