Originally Posted by
Street rider
Geometry is different, so they handle differently than one another. And while downhill bikes do take quite a bit of abuse, its usually in ways that BMX bikes don't, and the stresses on the frame are a lot different. Besides, the dropouts are smaller in diameter than a frame built for the streets/park, which won't hold up to the abuse as well either.
Yeah, obviously steel is better for taking a huge amounts of hits, but I was thinking alu might be fine for a bit smoother riding. I think the worst abuse for aluminum frame might be direct frame knocks, as it's softer than steel. Also, landing big jumps hard would probably eat up the rear dropouts.
Thanks for advice SR, I can always take the 20.8" steel frame out first and see what I'll use the bike for, then decide what to do regarding the frames.