Re: 1 inch spindle rating?
1" spindle axles can be 1,500 lbs, 2,000 lbs or more unusually 2,500 lbs rating.
99% of the ones I see are 2,000 lbs axles even though they have the 1,250 lbs hubs. That is just a standard size hub.
The loading is per hub so with two wheels you have 2 x 1,250 lbs capacity on the hubs.
The actual load rating is the weakest of the links - in this case almost certainly the axle which is probably 2,000 lbs.