On a dirt or street bike the derailleur is the lowest point after the pedals. Every crooked landing hits it, and every hit bends the hanger a little, until one day it starts jumping between gears.
What I did
I drew the original cage in CAD, then a second version with the same pulley axles but five millimetres shorter and with a thicker wall at the lower bolt, where it bends. The difference in clearance is small on paper and enormous on the track.
Machining and testing
7075 aluminium, two setups, about forty minutes of machine time each. The first set has been on Sender for two months and is still straight. The next batch is anodised orange, because why not.
