Originally Posted by
jaydotosh
I'll do what you said as soon as I get home today; the chain tension issue you raised was probably caused by me pedalling gently (with my hand of course) while the bike was upside down. I was doing this just to remove all the grime and dirt that was collected thanks to the lubricant I was using (motor oil).
Chain tension is determined by length and in this photo, the derailleur cage is rotated all the way back and not under much tension:
The red pulley should actually be at a 45-degree angle (closer to the ground) relative to the other one. If you're not in the granny-ring up front, then you need to remove 2-4 links from the chain as it's too long and slack.
Originally Posted by
jaydotosh
P.S. which component needs to be bent? Is it the metal body of the red pulley?
Sorry, typo on my part. It's most likely the derailleur hanger-bracket that's bent. But typically all the parts between the pulley-cage to hanger gets bent. Start with this photo:
Rotate the pulley-cage so that it's vertical, then pull outward to bend back into proper position. The two pulleys should be inline vertically, the lower one is currently bent inwards.