Originally Posted by
noglider
Speaking of robustness, the derailleur hanging out as it does is one of the most vulnerable areas of a bike and could use a big improvement. I don't know how it could or should be done.
As evidenced by the scrapes on used RD's, usually on the bottom side/edges, not to mention bent hangers.
solution is a roll cage for RD's. I believe SRAM had a token one for their IGH. it's design looks like it was an after-thought. What did they think was going to happen on a MTB or low end bike for kids when they were called to the house while riding a bike?! Drop (DS) and run!