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Old 08-02-2013, 09:45 PM
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maniac57 maniac57 is offline
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Join Date: Oct 2011
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Default Re: Buying a Used Bike? Things to check before you slap a motor on.

Originally Posted by comfortableshoes View Post
It was brought up in another thread that buying used bikes can be a carp shoot. Sometimes you get a deal and sometimes the deal turns into a nightmare as you strip it down and get into the innards. I started this thread so we can share our used bike hints and tips so we can all ride safely, even when we buy a used bike. All of the stuff I list below is in addition to making sure the engine will fit in the frame.

Things you can check my looking at a bike and frame:
#1 look for signs of obvious rust. Deep pitting in the paint can mean bigger issues hidden under the paint.
#2 Look for rust and corrosion around the rim and spokes. New rims can set you back a lot of dough.
#3 Look for scrapes and gouges in the paint. Deep scrapes and gouges can mean deeper damage to the frame that you can't see. Scrapes and gouges occur from the bike dragging on a rough surface, like being hit by a car or run over in the driveway. Look to see if the bike is missing the pedal on that same side that is a clear indication that the bike sustained heavy damage at some point.
#4 Look at the gear and cogs. Are they rounded over? Full of dirt and rust? Do you want to learn how to replace a cassette? No, you might want to skip a bike with a lot of junk in the gears.
#5 Spin the wheels are they straight and true or will you have to try your hand at truing them? Or pay for a bike shop to true them?

Things you should listen for:
#1 Grinding in the bottom bracket when you pedal. Are you capable of removing the bottom bracket and repacking it? No, move along. (This is a skill you should learn.)
#2 Listen to the hub. Do you hear grinding? Again, how do you feel about bearings and packing them with fresh grease? (This is something you should learn how to do anyway, but learn it on a hub that in good shape not one where you might need to order new bearings.)
#3 If possible shift the gears, how does the derailleur sound? Is it sloppy and loose? Do the gears sounds smooth or gritty? Do you want to replace the gears in them or do you want to ride right away? (An easy repair and not too expensive.)
#4 How do the grip shifters/ shifters work? Do they make solid clicks, do they roll smoothly?
#5 Spin the pedals. Do they sound gritty? You can lube them or buy new, but be aware this adds to the cost of the bike in the end.

Things you can feel:
#1 Gently press any areas of rust. Does it feel soft and spongy like it will give way at any minute? Unless you have skills in welding, run away, with a motor that rattle trap will kill you.
#2 Run your fingers over a few spokes. They SHOULD feel smooth. If they are rough they may be rusty. Sometimes the gritty feeling is just dirt. You need to be careful here, especially if motorizing.
#3 Squeeze the spokes. Are they loose and sloppy? Tight and happy?
#4 When you turn the handle bars how does it feel? Does it feel right or wrong? Is the tire all out of whack with the handle bar?
#5 The rear gears, if you run your fingers over them you can feel sand that you can't see.

If possible ride the bike. When I go to buy a used bike I take a mini compressor with me and even if the tires are rotten I'll pump them up for a quick ride. If the seller gets nervous when you do this, assure them you just want to make sure it's the right size for you. I like to see how a bike feels and handles before I buy it. I expect that the brakes won't work well, if at all and that the gears might be wonky. But I want to see if they will work and how much work I'm in for when I get it home. If they won't let me ride it I flip it over. Most of the time if they won't let me ride it I walk away. Usually they change their mind.
Riding the bike is a good way, even in a short distance to see if the bikes fit is right for you. Is the distance from the seat to handle bars good for you? Can you adjust the seat to a level for proper pedaling? Do the pedals rest at a comfortable position for cruising and not pedaling?

Things you can assume when you purchase a used bike and you are going to motorize it:

You will need to replace the following:
Brake pads
tires and tubes
pedal side chain

You will need to adjust the following:
shifting and derailleurs

Things you should check:
Alignment of the tire to handlebars, especially if the steering feels weird.
Hubs should be well lubed as should EVERYTHING else that needs it and you can get at with ease, or not ease. I use the tire change to check the nipples and condition of the interior rim. Seeing a lot of rust is not a good sign. Good rims and spokes keep you safe.

Obviously I'm a big proponent of buying a used bike. With the $150 you'll spend at Walmart you can get a full cromoly frame on a bike shop bike. Yes you will have to be patient and troll craiglist and other used sites in your area (Uncle Henry's in Maine, NH and some of MA.) You have to be willing to haggle a big, or pay their asking price. You also have to be willing to walk away if the bike is just not right for a build. But sometimes you will find a gem out there for the right price and when you get a motor on it you will be a happy camper.

Add your hints and tips!

(mods if I've put this in the wrong forum please move it.)
Great tips comfortableshoes!
All I would add is the following:

I like to pull the brakes and see if they release on their own easily. Run both shifters through the full range and check for rust on the cable that is exposed at the far end of the range. If the cables are rusty, you will need to replace them or risk breakage at the worst possible time. Even if you dis-assemble and oil them, they can still fail under strain once they get pitted.
Turn the bars 90 degrees and rock the bike back and forth. Look for slop in the steering head bearings and front hub. Hold the back end up and wiggle the rim to check for worn or sloppy bearings.
I true my own wheels so I also like to check several spoke nipple to see if they are rusted stuck or if they turn easily. Stuck nipples mean spoke replacements so I check before I make an offer. I've seen many bikes that looked great and yet required complete wheel rebuilding before the wheels could be trued due to stuck spokes. I check every other spoke on both sides of both save time.
It never hurts to deflate a tire and look under the rim strip, especially on steel rims.
If more is better, then too much is just enough.
If you can't afford it, build it yourself.
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