So does anyone know why the fixed side has smaller ball bearings than the free side? I got that the dust covers are different sizes because of the lockring threadings, but it seems it'd be cheaper to have the same size ball bearings on either side. Anyone know what the purpose of this is? Is it common to have different sized ball bearings in the same hub?

because they ******** suck. I have no other information to share.

it's not common, and it's not normal.
those hubs are notorius for being horrible and cheap and stripping threads if you look at them wrong.

on the upside, you can rebuild them, and when the lockring threads on mine stripped (coming down a big hill) i just j-b welded the lockring back on and went on riding.

ymmv.

These are just cheap and nasty hubs period. You may be able to get good service out of a pair but your chances are about 1/10.

I think Suzue are either:

Lazy - Cause they don't want to make any more than they have to of their good ProMax hubs. If people start realising that they actually do make good hubs, then they'll have to work a little harder, maybe stay later at work some evenings.

Cruel - They knowingly make a crud product just to laugh at all our pictures of crashes and grumpy faced people walking 10 miles home cause their threads stripped.

or

Fixie snobs - You make an affordable product thats awful. Fixie newcomers bowl up to try it out, spend what seems like a ton of money to convert their bike to a fixie. Pedal off, try a cool skid or even stopping without a brake. Strip the threads and have to resort to just running a singlespeed and thus hate fixed gears.

Can't fathom else why they haven't withdrawn or redesigned their product in the light of years of terrible customer feedback.

i personally haven't had a problem with the suzue jr's on one of my bikes aside from having to repack the bearings every so often and a bent axle when i popped a pothole pretty good. but yeah, you might as well spend a couple more bucks and get iro's/formulas/whatever. cartridge bearings are your friend.

edit - i should mention that i run brakeless (skips/skids galore) and beat the crap out of everything i own. i've also had these hubs for a little over 2 years.

you know, as much as people share Suzue horror stories, i think they do serve an okay purpose. my first wheel was a suzue hub, and it never died on me (i didn't ride it particularly hard, either, which says something), but it was an affordable way for me to realize that riding fixed was the absolute shiznasticism and that i wanted to stick with it and put down a bit more money for something that was going to last me through year-round commutes in new england.

Alright, I half expected this to happen. Yes I know the hubs suck. No mine has not stripped yet. Yes I have a brake. Yes I'll probably upgrade to a better wheel eventually.

I was just wondering about the sizes of the ball bearings.

There are smaller bearing on the fixed side because the lockring threading reduces the diameter of where the bearings go.