Commuting - Garage Sale Bike - Fixing it up

Hey guys, new biker here. I am actually hoping to purchase a new Giant Carbon OCR3 soon (Half price), but am going garage sale shopping tommorow to try and find an old road bike for commuting - basically times where I will lock up the bike.

My question is: What parts will most likely need replacing? Obviously all cases are a little different, but what are the parts I should look at the most?

All help would be appreciated - Thanks in advance.

I find that pedals, tires, and chains are the most likely things to be replaced on garage sale bikes. Since those are cheap-o items it shouldn't worry you too much. It's also a good idea to repack bearings too, since a lot of people leave their bikes in their backyards/or have ridden them so infrequently that the grease has solidified.

I tell you my build process ... bear with me

1971 10 speed = 25 bucks

Wider handlebars = 15$

Seatpost (Too short) = 15$

Bottom Bracket (destroyed) = 35$

Wheels and Tires = (tires and wheels were at least 15 years old) = 100 $ Craigslist - Thanks phillybill!

Crankset (170: too short ) = Excellent shape junk special 20 dollars form LBS.

Pedals = 50 $ clipless

Shoes = 80 buck ... I have them on right now ... mtb racing pedals. That comfortable.

Helmet = go crazy! ...is your mellon

Gloves = 15$ Target batter gloves.

Eye protection = 10$ Home depot clear plastic. Shatterproof. Stones fly fast, so bugs do :D

Clothing is a matter of opinion, but try riding with jeans and enjoy a itchy crotch.

The frame's the most important. Check for cracks, rust inside and out. To check inside, remove the seatpost and look inside. Bring a wrench and flashlight. While you're looking, might as well be picky. If you like lugged steel frames, look around a bit. Don't pick up a Walmart cheapo bike if you can avoid it. Pick up the bike to figure the weight.

Also, check the wheels for trueness, and take a look at the components and what level they are (low, mid or high end Shimano/Campy/Suntour). Check for fender and rack braze-ons.

As for replacement, that'll depend on the condition, but as mentioned, figure on replacing the cassette and chain and tires and tubes. You may want to lube and re-pack the bottom bracket and hubs.

If you can find one with aluminum wheel rims, they'll provide much better stopping grip for your brake pads when they're wet, compared to chromed steel. Also, don't buy one that's not the right size for you... stand over the frame and you want something like 1-2 inches of body clearance over the top of the frame.

Check the bottom bracket, not everyone takes care of it, and often gets wet, or stays wet. I do a bar change, and cable change. I don't swap out a chain until I've busted it. I've had good luck with chains. I repack all bearings, the BB the HS. I've been leaving wheels out of that repacking as I usually have a fixed gear wheel set ready to go.
Having said all this, I need to follow my own suggestions, I just picked up an old 3 speed, that needs all the above.

... dispose bottom braket

Check to make sure the seatpost isn't seized.