The derailleur broke near the hangar bolt whilst riding mid corner. It immediately caught in the chain and cassette causing the back wheel to lock, causing me to crash the bike. I get the bike maintained at Decathlon and the cassette, chain, front and rear derailleur were replaced less than 6 months ago, and I have done no more than 350 miles mostly on road during the lock-down. I see that another customer reported a break in the same place. This item is dangerously under-engineered and should be pulled from the shelves.
Worked with a 13-39 cassette, but the arm broke!
A sudden clean break of the arm next to the hanger bolt when changing between mid-range gears. I was not using great force on the pedals, and there were no signs of anything jamming. Was it metal fatigue?