Bicycle Safety Check
Even if you are not terribly mechanically inclined, you can perform a basic safety inspection on your bike to identify any potential mechanical or safety issues. Here are some tips to help you assess the condition of your bike, and spot any problems before they can cause real harm.
Wheels & Tires
Spin each wheel & make sure it turns freely, and that the rim isn’t rubbing against the brake pads (or the rotor, in case of disk brakes). Also make sure the tire isn’t rubbing any part of the frame, the brake pads or fender struts. If so, the wheel could be mis-seated in the dropouts. Loosen the quick release or axle nuts, reposition the wheel, tighten & spin again. If it is still rubbing, it may need an adjustment by a pro.
As each wheel spins slowly, check that it is free of bends, dinks or wobbles. Check also for loose & broken spokes. These problems require the attention of a bike mechanic.
Make sure the quick release skewers or axle nuts are firmly and securely fastened.
Check to see if the tires are inflated to correct pressure (embossed on the sidewall of the tire).
Brush off or pry out any debris embedded in the tire (you may be surprised to find good sized chunks of glass).
Examine each tire for holes, splits or dry-rot along the sidewalls. Replace tires if holes or splits are present.
Brakes
Squeeze the brake levers, and make sure the brake pads grip rims firmly before your brake levers "bottom out" against the handlebars. Lean on the bike and try to roll it forward as you engage the brakes.
Examine the brake pads to make sure they are securely attached, aligned with the rims, and not rubbing the rim or the tire. (If they are rubbing a tire, get it fixed immediately, or you may get a blow out).
Check also for uneven or excessive wear on the braking surface of the pads.
General
Let your bike drop from a height of about 8 inches and investigate any abnormal rattling noises.
Check for frayed, rusty or frozen cables.
Check the hub adjustments (the bearings in the center of each wheel). Grasp each wheel and try to shake it side to side. There should be no "play".
Check the bottom bracket adjustment (the bearings between the cranks of your bike). Grasp one of the crank arms and try to shake it side to side. Again, there should be no "play".
Check the headset adjustment (the bearings that allow your handlebars to turn). Holding the front wheel between your knees, squeeze the brake levers and shake the handlebar back and forth. You guessed it, there should be no "play".
If your inspection reveals anything that makes you uneasy, stop by Cosmic Bikes (or your preferred local bike shop) for an evaluation by a mechanic. Many problems can be addressed with a simple and inexpensive adjustment.