Originally Posted by
guy153
You get triple butted (or "dual zone butted" which I think is the same) on MTB downtubes quite often these days. It saves putting gussets on them, although personally I don't really see the point of gussets anyway.
Ooh, good point- and one I should have remembered since my gravel bike even uses a DZB downtube!
So to correct my earlier comment, besides the DZB downtube on a few offerings, modern steel bikes largely use DB tubing.