Originally Posted by
Midawi
The sound/grinding/resistance always happens at the same point in crank rotation, so maybe it is something in the bottom bracket... I just ordered the tools to take it apart and see if there is a problem. We'll see.
Check your chain tension aka check how tight your bike's chain is, with your crankset rotated to different positions.
Another thing about cheap bikes is the chainrings are not perfectly round or probably in your case with a crankset that has a welded on chainring, the chainring was welded on possibly slightly off-center.
Your chain from the sounds of what you describe, seems to be binding at high points of the chainring as a result of you tensioning your chain at a low point on the chainring.
Try finding the point of crank rotation where the chain is the tightest. Making note of that, loosen and retention your chain without moving the crankset position.