Review on SHIMANO Altus Direct Mount 🚲 Rear Derailleur for Mountain Bikes - RDM310 by Carlos Henley

short version - catastrophic failure after about 40 km with damage to me and my bike! DO NOT BUY! Long Version - I bought this to replace the Altus A20 on my bike. After 30-40 miles this thing failed catastrophically damaging itself and my bike. I'm not sure what happened, but this thing jammed sooooo hard it bent backwards, fell on my head and bit into the spokes of my impeller. and the chain is somehow hanging on the outside of the derailleur frame. I wish I could take a picture of this jam, but I didn't think about it until I removed the item. After removing it I found that 2 small tabs were broken off next to the mounting screw, one on the washer was bent about 45d from where it should be (compared to my Altus A20 this tab is about half that wide which was also weak) the other tab that is built into the derailleur was knocked out but the other tab was no longer functional. Upon closer inspection, I noticed how warped the Derailer's frame was and that the teeth of one of the sprockets were already worn out. When I attempted to reinstall my old derailleur, I found that this catastrophic failure had actually bent the bracket on my bike! I'm sure some of the spokes are bent too, but haven't gotten around to fixing it yet. I have had a bike all my life and have always repaired and maintained it myself. I have NEVER had such an extreme part failure let alone a part getting stuck in a wheel and damaging the bike frame! I will be returning this obviously defective item, I have attached photos of the damage to my bike's rear derailleur and frame. DO NOT BUY THIS AGAIN!