1.25 inch hitch receiver on back of monty

[dpam]

Our 5th wheel came with a 1.25 inch receiver on the back of our 3150RL 5th wheel. I'd like to carry two bikes on a bike carrier that slides into the 1.25" receiver. Is this hitch strong enough to handle two bikes on a bike carrier. The hitch is bolted to the frame with two brackets that are welded to the frame and there are 3 bolts on each side holding the hitch. I'm wondering if this 1.25" set up is reliable enough, or whether I should scrap it and get a 2 inch hitch installed. Does anyone use a 1.25 inch hitch, and what are your thoughts?

I guess I should have stated that the bikes are 21 speed mountain bikes. They are not motorcycles. I don't have a store bought bike carrier. I'm using a cargo carrier that slides into a hitch receiver. I have attached two bicycle fork mounts to the cargo carrier floor, so I will be removing the front wheels and securing the bike forks to the fork mounts and using straps to hold down the rear part of the bikes.