There are a whole host of reasons to NOT purchase bicycles from Wal-Mart. Poor assembly and substandard parts are at the top of that list. When it came time to purchase mine, I managed to find a $700 bike Wal-Mart was selling for $200. At the time, I wasn't sure I would be able to get back into cycling after so many years away from the sport, and didn't want to throw cash away on an item I would never use. Additionally, I figured it would be more cost-effective to slowly replace those substandard parts over time rather than suffer the up-front cost of a well-made bike. That last part has served me well.
Newton Bike Shop is only 4-miles from my house, so I am able to both ride it and walk it when I have it worked on. Upon purchasing the Wal-Mart bike, I had them tune it before I took it out, and they have slowly replaced parts as required. Its actually a pretty decent bike now.
But my mountain bike is another story altogether.
I keep my mountain bike in Pawnee Rock, and while its the same brand as my road bike, it was put together by some random Wal-Mart associate and I cannot walk the 12-miles to the local bike shop in Great Bend. Even if the mountain bike did have a quick-release front tire like my road bike (it doesn't) Newton tune-up's are two-thirds the cost of the ones in Great Bend. Needless to say, the bike couldn't utilize all 21-gears, which wouldn't be a problem in smooth-as-glass Newton, but a necessity on the dirt road grades here.
But when a marked "road" (with a street sign and everything) ended at a tree, I had to traverse part of a recently razed wheat field to hop onto the perpendicular road home, which caused both my tires to go flat two miles from home.
Newton Bike Shop sold me some Stan's (like Slime but better) for the innertubes, and Kevlar lining for the tires. So while I had both tires off, I tuned the bike myself. This required much cursing and gnashing of teeth for the front and rear derailleur, and a steep learning curve through trial-and-error on the V-brakes. But I am pleased to say, the wheels now roll smoothly with no rubbing, and I can utilize all the gears.
Unfortunately this took so long it replaced my riding time today, but I'll be ready tomorrow!