Originally Posted by
DX-MAN
The Huffy looks like the old-style friction shifter equipment; unless the derailleurs are FROZEN/rusted, there should be no issue. Just make sure the cable tension is right, and the limit screws let the unit move as far as it needs to for all gears. Use a light oil on the derailleur pivots. A derailleur is pretty much a "slave" device, it only does what the shifter tells it to.
Your Murray needs a new crank; one-piece cranks are pretty much standard on bikes under $100 new, all over. Google "one-piece cranksets for sale".
The rear derailleur just doesn't seem to spring back outward properly, I'm not sure what the problem is(the cable may need replaced but I'm not sure that it's causing this problem, I will check for rust)
The front derailleur is frozen up but doesn't have a lick of rust on it. It feels to me, who is a Newb, as if the spring inside is too tight.
And as far as the price, lowest is best for me.