Any anecdotal testing on 80/20 roller bearing load capacity?

[Nat X]

I want to build some sliding shelving. 80/20 will work great, but their rollers have no published load capacities, and when I emailed them they basically said they had no idea, but they didn't recommend putting more than 35 pounds on one of them. This seems incredibly silly as there's pretty much no way the $30 roller with the steel bearings has the same capacity as the $8 one with the bronze sleeve rubbing right against the plastic, but that's their script and they're not really interested in telling me where they source their bearings from so I can get more info.

So... anybody ever put more than 35 pounds of weight on one of these things and lived to tell about it?
https://8020.net/shop/40-2758.html

My plan is to distribute the weight across four per shelving unit, and I'm hoping I don't need to make that 6 or 8 as they aren't cheap. They will not be moved all that frequently, so most of the load will be static. 

 

[pixelated]

Not something I've worked with. But, I suspect that what the bearing can support may be less of an issue than what the flange of the T-slot can support. Offhand, it seems like 35 pounds on one wheel truck would be plenty, considering that the PSI load on the flange would be much higher, given the tiny contact area.

The bearing number should be marked on its flange someplace which should get you the load rating, assuming you had one in your hand.

 

[Nat X]

I'm waiting on delivery of one so I can pull the bearings and see if I'd need to swap them and/or re-cast the wheels themselves in something more rigid.

I was planning on running bolts straight through the extrusion rather than relying on the T-slot for attachment, but the contact area should be substantively greater in either case given the size of the plate the rollers are actually mounted to. Whether or not the bolts on the wheels can hold is another matter I suppose.

 

[Svar]

The bearing in the wheel is 6000Z (as you can see from the picture), which is 10x26x8 mm ball bearing. Its load ratings are: dynamic 4,620 N (1040 lbf) and  static 1,960 N (440 lbf). I would not be worried putting several hundred pounds on those assemblies.

 

[Nat X]

Well your eyes are clearly better than mine because I can't read that at all!

That's about what I figured--there's no way the $20 difference in price wasn't buying a lot more strength.

 

[Gregor]

Their limit might not stem from the bearing, but the roller on it (made from 'Nylon PA Glass Fiber Reinforced K222-D') which will concentrate the load onto a somewhat small area of it.

 

[Svar]

Their limit might not stem from the bearing, but the roller on it (made from 'Nylon PA Glass Fiber Reinforced K222-D') which will concentrate the load onto a somewhat small area of it.

I agree, bearing is not the weakest link. Still, nylon is often used in casters. It should handle 100+ lb per wheel of this size.

 

[Nat X]

I'm hoping it doesn't deform too much under load, but if not I can just buy one of the things and re-cast numerous copies in some Smooth-Cast 385 for roughly the same price (but a lot more effort).