Inspecting and Test Riding A Bicycle Before Purchase

If you are buying the bicycle to ride it, as opposed to purchasing it for parts, you want to make sure that it is rideable, has no fatal flaws and you are aware of any needed repairs. 1- Check the frame - You can't easily repair a frame.  If the frame is damaged, don't buy the bike.  Visually inspect the frame for signs of damage from crashes.  Run you hands over the main tubes of the frame (seat tube, top tube and downtube) to see if there are any bumps or indentations.  If the frame is carbon, feel for cracks. If you find any cracks, don't buy the bike.  Look at the lugs and welds for cracks.  Again if there are any cracks, don't buy the bike.  Check that the fork is straight.  Check that the rear triangle is not bent  On steel frames, check the frame for rust.  Small patches of surface rust can be fixed, but significant rust should be avoided.  On steel and aluminum frames look for dents.  A steel frame with a dent is rideable.  An aluminum frame with a dent will have lost some of its strength.  However since the frame is the most difficult and expensive part of a bike to repair, if the frame is not good, pass on the bicycle 2 - Check the fork and headset - Visually check to make sure that the fork is straight.  Lift the front of the bike off the ground and pull on the fork to see if it is loose.  It should not move side to side.  To check the headset (the bearings that allow the handelbars to turn), lift the front wheel off the ground by holding the top tube of the bike.  If the headset is loose, the handlebar and wheel will flop to one side.  This is something that can be adjusted.  Put the bike back on the ground.  Apply the front brake and while holding the front wheel between your knees, try to shake the handlebar back and forth.  If the headset is loose, there will be some play in the handlebar and you may even hear clicking.  A loose headset needs to be repaired. 3 - Check the bottom bracket - The bottom bracket is the mechanism and bearings where the cranks (pedal arms) connect to the frame.  Grasp one of the crank arms and try to shake it back and forth.  There should not be any "play" in the bottom bracket. 4 -Check the wheels and tires- All spokes should be tight.  Touch each spoke to make sure none are loose.  Look at the hub and rim to make sure no spokes are missing.  Lift the front of the bike by the handlebars and spin the front wheel.  It should not wobble side to side and should not rub on the brake pads or the frame.  Do the same for the rear wheel.  If either wheel rubs, make sure the wheel is seated in the dropouts.  Loosen the quick release or axle nuts, repostion the wheel, tighten and spin again.  If it is still rubbing or if it wobbles, it needs to be trued.  Check the hub adjustments (the bearing in the center of each wheel) by grasping the wheel and trying to shake it side to side.  There should be no play in the hub. Check the tire pressure and look for dry rot, cuts or the tube extending out of the tire.  Even if a tire can be inflated, it still may need to be replaced.  Tires with cuts are more likely to get flats and tires with dry rot can pull off of the rim when cornering. 5 - Check the drive train and shifting - The pedals should turn smoothly.  Look for rust on the cables.  Rusted cables need to be replaced.  This is not an expensive repair.  Next, visually inspect the chain and gears for rust.  A rusty chain should be replaced, but it may be possible to clean it.  Check the chain for bad links.   This can be done by holding the bike and rotating the pedals backwards with your hand.  Watch the chain to see if it skips or if there are links that are not bending around the cogs.  Next you want to test the shifting.  Have someone lift the back of the bike so that the rear wheel is off of the ground..  Rotate the pedals with one hand and use the other hand to shift through the gears.  Check both the front and rear gears.  The chain should shift smoothly and should not skip gears or bounce out of a gear.  After shifting , the gear change should occur within a pedal revolution.   If the shifting is not smooth, a tune-up or minor adjustment may solve problem.  If the bike can't shift to all gears, more extensive repairs may be needed.   6- Check the brakes - The brake pads should grab the rims of the wheels firmly.  The brake lever should not "bottom out" against the handlerbars when squeezed. While appling the brakes lean on the bike and try to roll it forward.  The wheels should not be able to turn.  Look for breaks and splits in the cable housing.  Look for rust on the cables.  Check that the brake pads are not worn excessively, that they are securely attached and that they are rubbing the rim and not the tire.  Brake pads that rub the tire need to be adjusted immediately since this can lead to a blowout.  Replacing brake pads and cables are minor repairs, but you should aware if these repairs are needed prior to buying a bike.  For many used bikes, the brakes need to be adjusted, but new parts are not needed. 7 - Pre-test ride safety check - Complete all of the above checks.  If the head set, bottom bracket or hubs are loose, do not ride the bike.  If the brakes do not strongly grab the rims, preventing you from pushing the bike foward when applying the brakes, do not ride the bike.  If the bike has passed the inspection,  adjust the seat to the proper height and verify that the tires are inflated. 8 - Test Ride- Put the bike in a middle gear.  Ride slowly at first, just rolling .  Test the brakes.  If the brakes can not stop the bike when you are rolling slowly, do not continue riding.  If the brakes are good - continue riding, listening carefully for any noises or rubbing.  If any noises or rubbing are detected, get off the bike and verify the problem before continuing.  If there are no problems, begin to pedal and listen for noises from the bottom bracket.  Shift through the range of gears as you ride.   You already checked the gears during the inspection, but often problems will show up when riding due to the extra tension on the chain.  If the bike can shift to all gears and has passed all of the early checks, it is in good shape.