The marine grade 316 bolts seem strong enough, but not as strong of course as a 5/8" heavy bolt that was original. When this is all together properly, the bottom of the tire is resting on the four arms of the mount and that is where all the force is going. That hub and bolt is there to keep it from wandering off the mount.

After this part is done, I need to find a durable cover for the tire to keep debris from collecting up there and being ejected all down the road while driving. The OE covers seem pretty pricy and I doubt that vinyl is any better than after market vinyl. Thinking that canvas with a healthy dose of waterproofing would be the better material.

 

Look at Marine shops that make boat covers. They can make you a great cover, not that expensive either.

 

West Marine is probably the place to check for a cover I guess. Maybe ask some of the marinas.

Also there is a harder variety of stainless that the bolt place I found offers. Might consider that instead of 316.

 

The place I found for stainless fasteners is https://marineboltsupply.com and they offer 304 and 316.
From other research, it seems that 316 is as hard and as corrosion resistant as you can get in stainless, at least from regular suppliers. Their sales guy has to source me a bolt they don't carry, because all their 7" bolts have an unthreaded portion that is too long for what I need, unless I stack a bunch of washers under the Nordlocks. Guess I should check and see if he can get Nordlock washers too, since they are not in their catalogue.

 

for a cover, you might try covers & all ...thy can make custom covers for anything. I had them make covers for my seats and console on my boat. They stood up to Florida sun and heat better than anything else I have seen..... https://www.coversandall.com/all-products.html

 

Sounds like a real good option. What did they make yours out of? They already have a tire cover template. The elastic tie down does not sound like the best thing for a roof mount though. Might have to figure out a mod for that.
https://www.coversandall.com/custom-...re-covers.html

 

The fabric is called "Color Tuff."
They can give you an option just to have grommets without the elastic or nothing at all. They are very easy to work with on modifications or custom designs.

 

They don't give that grommet option on the page, but Color Tuff is an option. When it gets to that point, I can contact them directly and see what they can do.

Edit: Oh yea, they spell "tire" funny, lol.

They did get back about the grommets. Yes, they can add them and they need to be mentioned with spacing and position information in the Special Requests field.

 

Finally found this. I don't remember if I saw it back when I was hunting for the rack back in 2002ish but the prices he has listed look familiar.
http://www.angelfire.com/mt/offroadin/tech2.html