I've pretty much run every rim forged aluminum, cast, spun, and also steel.
- Cast Aluminum: No thanks, they don't give and are unforgiving. Even if you don't break it, scraping it on rocks will eventually create leaks or you may just crack it. Of course worst case would be to bust one.
- Spun Aluminum: They are Ok and can bend to some extent before they break. They also can be hammered on to get you off the trail but be careful, not too much or it will break. You still have the issue of scraping against a rock and creating a leak.
- Forged Aluminum: Very strong and you can beat on them all day long, again you still have single issue of scraping against rock due to aluminum being a somewhat soft material.
- Steel Rim: Very strong rim, can take a beating and keep right on going. They do well against the rocks when scraping against them, if you can scrape them up enough to create a leak a couple good swings with a hammer will seal it and get you off the trail. If you bend one you can hammer it back without any worries of breaking it or cracking.
I am sold on steel, all around strongest and most workable setup on the trail plus they are cheaper to buy when you do damage one beyond repair.
