When I got the bike I knew nothing about servicing or working on it. I just had an idea that it would be a fun hobby and a nice way to get around a new area. At first things were great, accept for some adjustment issues (with the derailleurs and brake pull). After the miles started piling up, it became clear the bike was in need of a tune up. This is when I found out the difference between high end components and what my bike had. Trying to fine tune the hubs after you regrease the bearings is an art, this process is more difficult the further you get down the list. I couldn't find that happy medium between the wheels turning freely and not wobbling around on the axle. So I made the transition to sealed cartridge hubs and never looked back. Also, the drive train had a freewheel assembly, and over time my rear axle was becoming bent as a result of the power transferred from the cranks. As far as the frame becoming fatigued and failing, I never had a problem with that. Then again, I never took my bike down K2 either.
The bottom bracket was an un-mitigated nightmare, the proverbial can of worms if you will. The bearings were separated by a retainer ring which meant that the manufacture could get away with using less, which I didn't think was a huge deal. In fact I thought it was nice that the bearings were all held in place by a nifty ring so that I wouldn't lose any. After struggling with this messy operation, I finally repacked the bearings and thought my job was done. When I took it out for a ride, every thing was hunky dory for a few miles then the crank started to wobble back and forth as I applied my weight. Evidently in my infinite wisdom, I had not tuned the bottom bracket as well as I thought. The ride totally screwed up the bottom bracket. However this was not a huge deal because a sealed cartridge BB is fairly in-expensive. I can't blame the manufacturer for my BB woes because it was probably my fault in the end.