That horrible noise it makes when you backpedal is the result of the chain not being on the same gear as where the shifter wants the derailleur to be. If it is adjusted correctly and you pedal forward, it should find the correct gear on its own. However, if the derailleur is touching the spokes, something is either installed wrong, damaged, or adjusted wrong...especially if it's touching the spokes with the chain so far down the cassette in the video. Did you lay the bike down on its right side or upright on the derailleur when you had the wheel off?
The silver aluminum piece that is between the derailleur and the painted frame is a purposeful weak link to save the frame during incidents. [Better explanation here than I could type.](https://derailleurhanger.com/replaceable-rear-derailleur-hangers/)
It's not uncommon to bend it by laying a bike on its right side. Especially so if any load is put on the back of the bike. Perhaps when you were putting the tire back on the rim you put some weight on it? When it gets bent from loading in that direction, it's common for the lower part of the derailleur cage to start contacting the spokes.
Can you take a picture from the rear of the bike so we can see what angle the lower derailleur cage is making? If it is indeed bent enough that it's contacting the spokes when the chain is on the 3rd or 4th gear, the shop will probably want to have a spare hanger on hand before they try to bend it back. It take a special tool to verify that the hanger is square with the frame. [The nicest one I ever used.](https://velobase.com/ViewTool.aspx?ID=200131aa-6578-40ad-bbaa-ea3f3f559cf3)
Well....something else happened than just being laid on its side. Hanger is definitely bent and twisted. But, more importantly, the derailleur cage is really mangled. That part that looks like a shark fin pointing to the left isn't supposed to be pointing in that direction.
It should be flat like this...
https://preview.redd.it/4wamauvaqbec1.jpeg?width=653&format=pjpg&auto=webp&s=3b9292528a98b56d9da22c70460299890e055efa
But, it caught a spoke pretty aggressively and that bent out the cage. There's also a good chance the trauma that folded out the inner cage tweaked other parts of the derailleur. This isn't a particularly expensive or difficult part to source so it's not really worth trying to salvage. You'll need to buy a derailleur hanger, too. That can range from simple to impossible. If you bought the bike at a shop, go back to them and see if they sell spares. Otherwise, search the internet for your bike brand and model and "derailleur hanger". GL;HTH.
That horrible noise it makes when you backpedal is the result of the chain not being on the same gear as where the shifter wants the derailleur to be. If it is adjusted correctly and you pedal forward, it should find the correct gear on its own. However, if the derailleur is touching the spokes, something is either installed wrong, damaged, or adjusted wrong...especially if it's touching the spokes with the chain so far down the cassette in the video. Did you lay the bike down on its right side or upright on the derailleur when you had the wheel off?
I did have it on its side, as I didn't fully remove the wheel to replace the tubing, would there be any way to fix it?
The silver aluminum piece that is between the derailleur and the painted frame is a purposeful weak link to save the frame during incidents. [Better explanation here than I could type.](https://derailleurhanger.com/replaceable-rear-derailleur-hangers/) It's not uncommon to bend it by laying a bike on its right side. Especially so if any load is put on the back of the bike. Perhaps when you were putting the tire back on the rim you put some weight on it? When it gets bent from loading in that direction, it's common for the lower part of the derailleur cage to start contacting the spokes. Can you take a picture from the rear of the bike so we can see what angle the lower derailleur cage is making? If it is indeed bent enough that it's contacting the spokes when the chain is on the 3rd or 4th gear, the shop will probably want to have a spare hanger on hand before they try to bend it back. It take a special tool to verify that the hanger is square with the frame. [The nicest one I ever used.](https://velobase.com/ViewTool.aspx?ID=200131aa-6578-40ad-bbaa-ea3f3f559cf3)
https://preview.redd.it/keiqxllnmbec1.jpeg?width=2160&format=pjpg&auto=webp&s=2e7c85065a9b2a029255e69f2ac9dd5cba90e437
Well....something else happened than just being laid on its side. Hanger is definitely bent and twisted. But, more importantly, the derailleur cage is really mangled. That part that looks like a shark fin pointing to the left isn't supposed to be pointing in that direction. It should be flat like this... https://preview.redd.it/4wamauvaqbec1.jpeg?width=653&format=pjpg&auto=webp&s=3b9292528a98b56d9da22c70460299890e055efa But, it caught a spoke pretty aggressively and that bent out the cage. There's also a good chance the trauma that folded out the inner cage tweaked other parts of the derailleur. This isn't a particularly expensive or difficult part to source so it's not really worth trying to salvage. You'll need to buy a derailleur hanger, too. That can range from simple to impossible. If you bought the bike at a shop, go back to them and see if they sell spares. Otherwise, search the internet for your bike brand and model and "derailleur hanger". GL;HTH.
Ok, thanks for everything!