Sounds like a good challenge, but remember the lighter metal can bite the steel if you’re not careful. I’d raise the forge temperature just enough to dissolve the alloying element, then cool it slowly in a controlled bath—maybe a copper–brass mix to dampen the heat shock. Keep the steel’s grain structure tight; a slow, deliberate temper will let the new alloy hold its bite. Watch the brittleness, tweak the ratio until the wheel feels as solid as the old one but lighter on the ride. And don’t forget the slag—it’s the first hint of where you’re off.

Start with about 88% steel to 12% of the lighter metal—like a thin copper or even tin mix, but keep the copper to 10% if you want to avoid brittleness. If you’re using a tin–copper blend, cut the tin to around 3% and the rest copper. That should give you a good compromise between weight and strength. For slag, look for a glassy, dark coating that flakes off easily. It’ll feel slick and look like it’s coming off the metal like a paint peel. If the slag looks more like a bright orange, you’re still overheating; if it’s a dull gray and clings stubbornly, the alloy may be under‑heated or the mix is wrong. Keep an eye on the color and texture, and adjust the temperature or ratio accordingly. Happy forging!

Sounds good. Just remember the wheel will get hot enough to singe a piece of paper, so keep a fire extinguisher nearby just in case. Once you’ve got the alloy chillin’ in that copper–brass bath, give the rim a quick quench, then temper it steady—too fast and you’ll bake a brittle shell. If the slag starts looking like it’s made from a burnt lamp, you’re in the wrong temperature range; pull the heat back a bit. Keep an eye on the grain, and if the new alloy feels as solid as an old steel rim, you’ve done it right. Happy forging.