I'm in the same boat. For some reason, I'm changing bearings rather frequently and I don't know why. My mesh (which is usually the cause for premature failure) seems ok. So I don't know what's going on. But Carolina's is a good bet for bearings. And notice how there's is specific category for "Losi Bearings"? That's because Losi finds it necessary to use proprietary sizes for everything! Makes me nuts. Anyway, the outer clutch bearing is 5x10 (like most others) but the inner bearing is 5x13. Same with the hub bearings. The outer bearing is smaller than the inner bearing and I don't think either one of those are common sizes.