Out for the 4th ride on my Norco Fluid HT+ and without any rock strikes or falls my shifting suddenly became Uber gritty and terrible sounding. Quick look back revealed my lower rear jockey wheel totally out of position and bent spider on the derailleur. Anyone else experienced this? I’m thinking it should be covered under warranty…

So it bent on its own just riding along ?

Yeah mech failures are hard to put through as a warranty job as said it did that all on it’s own? Nothing at all happened?

Just noticed this post and thought I would chip in while the rear mech experts are about, just had this happen for the 2nd time in a couple of months…

Both cases exactly the same, top jockey gets completely pulled off writing of the cage but leaving everything else in an OK condition, any thoughts as I am stumped other than bad luck (i.e. a rock strike) two times in a row?

No rock strikes. Bike not dropped. Done some small jumps / drops but nothing major. Very much trail riding so far. Just sounded like sudden chain drop / really grindy for no reason whilst riding

Should be obvious that it hasn’t been hit. I imagine it looks pristine apart from being broken!

Not a scratch on the derailleur. Sadly the same can’t now be said for the chainstay which has a lovely bare allow finish in key areas now.

B-screw not wound in enough? So the top jockey wheel isn’t clearing the bigger cogs properly. If that makes sense?

B screw would appear to be far enough in. Protrudes further than on my xt equivalent though. Problems happened on small cogs somewhere around the 16t range.

Chain too short, so it’s pulled too tight at bottom out?

Maybe I’m being thick, but what’s a derailleur spider? Do you mean the cage?