To pick the right size bicycle, you want to measure your height, and specifically your inseam (inside leg), in proportion to the size of the bike frame. The inseam measurement determines the seat height, or the “stack.” Next, you must calculate the “reach,” which is the horizontal distance between the bottom of the frame and the head of the bike -- or, in layman’s terms, the distance between seat and handlebars.
Keychain style flashlight or headlamp, LED type, not incandescent:   The keychain style is tiny and lightweight, the headlamp style is a bit bulkier but easier to use.    You can get these for a couple of bucks or less at the local big box hardware store.  The LED ones are lighter, more durable and last considerably longer.   Very useful if you need to make a repair after dark!  I keep a keychain style one as a backup as I normally have a headlamp in my backpack.
It’s both surprising, and not, if you think about it. The way I’ve usually seen it happen is first the rear tire goes flat, then the front one. My theory is that both tires went through the same pile of glass/thorns/metal bits and they both picked up junk. the reason for the flat occurring on the back first is because there’s more weight on that tire, so the offending article works its way through the tread more quickly.
Man, if you're starting out and you know you'll need several components for a bag... just get this. It will save you so much time picking everything out that even if you balk at the price (amazing value, by the way) I bet that if you did the math using your hourly wage and the time spent picking everything out and making sure it fits... you'd save a lot of money and a lot of irritation if you just got this. Just get this.
I brought my bike into Kyle's shop to fix the noise in my rear wheel. The mechanic suggested that I need to overhauled the rear hub for $30. The next day the noise came back even worst. I brought it back to the shop and they said it was the freewheel driver not the hub that needed to be work on and it would cost me extra $30 to overhauled it again plus the part to fix it. At this point I walked out of the shop and took my bike to David's world. The mechanic at David's world took a quick look at the rear hub and indicated that the axle was put back too tight when Kyle's mechanics were working on it and further identify the issue. I ended up paying David's world the $30 plus part to fix my bike, but the major different is that David's World has 30 Days services warranty claim. If you have any issue with your bike within the 30 days the service was performed you can bring it back and they will fix it no question ask.
Many bikes, including older models and track bikes, have bolts attaching the wheels to the frame instead of quick-release levers. If your wheels are bolted on, in most cases you’ll need a 15 mm wrench to remove it. We didn’t test wrenches, because there aren’t that many tiny 15 mm wrenches, but the GearWrench 15mm 12-Point Stubby Combination Wrench is perfect for stuffing into a flat kit and Amazon reviewers seem to think the same. Our experts also recommended the Surly Jethro Tule, but it’s expensive and harder to find.
Friction gear systems are a lot simpler to adjust, because the movement of the derailer cable can be modulated as you ride, every time you change the gear- they require less cycle maintenance. Modern index shifting systems are a little more complicated because each ‘click’ must release the exact right amount of cable to allow the derailer to move the correct distance to move the chain from one gear to another. Setting up and adjusting a derailer is not difficult and requires only basic tools, but there is a methodical procedure to follow.