So I figured this would be a good place to start. I want to start biking. I'm 5'7 and some about a 31" inseam. I can get a good deal on a 2006 Roubaix SL frame with a sadle, seat spot, fork and a double crank set. Is there anyway someone could advise me of somewhat cheaper components to finish it fairly cheap. Im in college and dont roll on gold rims Im new to the whole thing!!!
BUT Im good with mechanics though new to bicycles..
The idea behind this is I figured I could get a much better bike used than if I bought a new one for the same price (similar to cars right )

So I need a handlebar:
rims
Cassette
front, back derailleur
Shifter,
breaks | seems these two are combined often
chain

What confuses me is the difference between certain things!

Looking at the Sora line (heard its best bang for bucks in the lower end)

For example
https://bike.shimano.com/publish/cont...e-rd_road.html
https://bike.shimano.com/publish/cont...e-rd_road.html

Maximum Sprocket |
Minimum Sprocket | What is that?

These two have a different front maximum difference and capacity, what are these?

What is the difference between a brazed-on and a band mounting of the front derailleur??

I know that is a lot of question and information. But I like to build my knowledge... any help will be greatly appreciated

oh and pedal but will talk about this later..

Piecing together a bike is absolutely the most expensive way to get yourself one. If you're on a budget, you should buy a complete bike that is fully specced with parts you'll be happy with.

Cambria Bikes is selling the Ultegra rear derailleur for a steal.

For shifters and front derailleur, Tiagra and the best bang for the buck in the lower end.

A cheap low end cassette will do. The difference between low and high end cassettes is mainly in weight. Make sure all your components are for the same number of cogs.

Look at some dual pivot Tektro brakes.

GS and SS are different derailleur cage lengths. A longer cage lets you have a wider gear ratio. Get the long cage version.

Go to your local bike coop and get some free handlebars and $50 dollar wheels.

what's your budget?
I assume this is for commuting/errands purposes.

Work out/ interest in the sport doing it as a hobby but somewhat seriously.. do something with myself..
several friends are biking I d like to do it too. Ive had a interest for a while actually

You will be far better off buying a complete bike. If you had a good knowledge base on bikes, you could probably build up the frame for a decent price. As you are just starting out, it will most likely lead to frustration and higher cost.

Are you going new? Like stated, this will cost you. Look for a donor bike on craigslist. If you are at college, check with your maintenace dept and see if they have any abandoned bikes. You may also have a bike kitchen in your area. It will give you access to tools and small parts. Goodluck.

A good component for the money, so good in fact I know people that race on this stuff, is the Shimano 105 group. Their inexpensive and very reliable.

Some of the cheapest costing rims yet still very good are Sun rims.

Handlebars can be had cheaply as long as you don't go with some carbon fiber bar which would be crazy to do when you could spend that money instead on better wheels which is where you feel a noticeable performance difference vs lighter bars.

And piecing a bike together is more expensive then buying the whole group as a whole, BUT if you don't have the cash and your only way to buy a group is to put it on a credit card then you lost the savings anyways with paying high interest. So buying one component at a time as you can afford it is not a bad idea entirely. You can do the same thing with tools, as you buy a component and you need specialized tool(s) to do the job then you just buy that tool(s).

+10 Piecing together a bike only makes sense when you already have a stash of parts. Since you don't, it will be a lot cheaper to just buy a complete bike (used of course). Since you brought up cars, this is very similar to a car. Imagine buying a frame, and building up a car from that. Buy an engine, transmission, all the body work, interior, etc.... Well, its the same with bikes.

I can tell you don't restore cars, I know lots of people who have done that which you speak of.

And I bet the total cost for a car they restore is significantly less than had they gone out and bought a used Ford Focus. If the OP wanted to restore a vintage Paramount I could see the point. But getting a basic, serviceable bike that way, especially for a novice, is not cost-effective.