[Whiskey]

Originally Posted by Styrak

That's a car.

You're forgetting that the ball bearings in these are TINY are prone to failure. I just sold a buddy a 9mm bearing gearbox which I trust more, because the bearings and balls themself are huge compared to 6mm ones.

I'd still recommend solid metal bushings over bearings any day.

Yes very much like the crankshaft and rod bearings (there more of a bushing than bearing) in a motor, but they have a constant supply of oil from the oil pump to provide lubrication and help cool the bearings so they do not become warped, un like an AEG's bushings which will eventualy disperse the all the extra lubricant from the bushing journal to the point that only the remaining grease will provide lubrication for a certain period or untill it becomes too contaminated with dirt and metal shavings making it ineffective. There is not a huge aftermarket for 9mm bearings at the moment, but still bigger should be better, well as far as stock bearings go anyways. You should be able to damn near pull any spring you want with kanzen 7mm bearings let alone so it really comes down to the quality of the bearing used not always the size, i'd rather use 6mm kanzens over stock CA 7mm units. If you go bearings buy quality and you should be good to go (as with all aftermarket upgrade purchuses).