Bike won't shift into 2 largest rear cogs (lowest gears) I replaced the rear derailer on my bike after Schwinn sent it to me. The old one had a bent piece.

I can't shift onto the largest 2 rear gears. I set the shifter to the lowest setting, but the chain won't shift onto either of the 2 largest gears.. It looks like the rear derailer isn't aligned straight with the rest of the bike.

In comparing to another similar bike I have that works fine, I can see that the rear derailer on the properly working bike is perfectly aligned compared to the gears.


                
            

Update : I just fixed this (thanks to the suggestions) by tightening the tension cable and also by loosening the H Screw (assuming that is what it is called)...it works perfect now..

update 2 : This question seemed to have got a few views and so updating with some additional information.

The first video sent to Pacific cycles

                
            

They were awesome and sent the derailleur (I did not know what this part was called earlier) to me and I put in the new derailleur and then asked this question on stack

                
            

I sent the question above to Pacific cycles also and they also replied

with the help of folks here and Pacific cycles I was able to fix this
Luckily in my case it was a simple issue


                
            

Thanks,
I didn't see the video but if your talking about the last 2 lower gears you may need to loose the tension cable. if its the top 2 big gears then you may need to tighten.

make sure you derailleur is installed correctly. make sure the last pulley lines up at all cogs especially the biggest one, using your hand and pushing this up and down the cassette, make sure it clears.

try to unbolt the cable, back out on the gears with shifter and back out the fine tune barrel adjuster located on cable/derailleur. pedal, then chain should drop to last small cog. then pull cable hand tight and screw bolt back on cable. make any fine tuning with the barrel adjuster when shifting up.

those are some tips from what I would assume...maybe others can help :)