The bottom bracket (where the pedals connect to the frame)- consists of loose bearings that run in bearing races, and usually has a cheap seal, (or no seal at all) to keep out moisture. Ride frequently in the rain, and the bearings rust out. Better bikes use a sealed cartridge This UN 55 is an inexpensive one, but it probably would cost CCM $3 to use it.
Same deal with the headset (where the fork attaches to the frame);
The entire wheel set (rims, hubs, spokes); The cheapest rims are made of chromed steel- Heavy, and they rust out. (This CCM has alloy rims, I believe, but the alloy composition varies) Typically, the spokes on these bikes are plated steel, rather than stainless. If the spoke nipples rust (and they always do, it seems), it makes it almost impossible to fix a "wobbly", or out of true wheel without replacing the spoke and nipple.
Shifters and derailleurs ; Poorly riveted together pivots on the derailleurs, or derailleurs that were left over from some other model bike, and then simply slapped on a different model, even though it only "sort of" has the same travel distance. Shifters that are mainly plastic and little lubrication.
So pretty much everything about this CCM is junky.
I've had to repair countless CCMs and similar 'dollar store' bikes, over the years. The kid's bikes (24" wheels and under) are even worse, with, amongst other horrors, one piece cranks or "pedal assemblies" that inevitably become loose.