1. It is NOT cheaper than just buying a bike.

2. You don't have the right tools.

3. There is standardization, but only sometimes.

4. It's completely worth it.

As I've mentioned, I built one of my bikes ( Amelia ) myself. Now, when I say "built," I don't mean I got out a welding torch and some steel pipes. That can be done, but it's well beyond my abilities. I assembled her. I had a very clear vision of the bike I wanted and I knew that the only way to get that was to do it myself. So I did my research, hand-picked every single part, and then put it all together (with a bit of help from my local bike shops on a few of the more complicated tasks). In the end, I got exactly the bike I wanted and it was an incredible learning experience. That said, there are a few things I learned in the process that would have been nice to know when I started.When I began, I figured that I could save some money doing it all myself versus just buying a fully assembled bike. That wasn'tI did it, but I thought it would be a nice perk. I was wrong.My assumption was that, since the assembly is factored into the price of a retail bike, removing that step would reduce the cost. However, I didn't think of the flip-side: parts. Major bicycle manufacturers like Giant and Trek can buy components wholesale and get far better deals than you or I buying a single derailleur.I was extremely fortunate, because my bike was a graduation present from my parents. I researched the components I wanted, and they bought them for me. It was an amazing present because I could not have paid for it all myself. However, I did have a budget to work with.This was harder than I expected. It wasn't even the frame that cost the most money, it was the little things. The derailleur, crankset, wheels, tires - those are what added up surprisingly quickly. However, doing my research and shopping around enabled me to only goover-budget, while still buying quality components.One of the great things about bikes is that about 80% of mechanical problems can be solved with a set of Allen wrenches, a screwdriver, and some chain lube. One good bike-specific multi-tool will have nearly everything you'll need to keep your bike rolling smoothly.The keyword is "nearly." Bikes are wonderfully simple, from a mechanical point of view, and the tools needed reflects this. However, there are some unique tools that youwill have if you've already built a bike. For example, to make sure your cassette (the rear gears, in non-bike-speak) is tightened and won't come flying off in the middle of a ride, you need one of these:It's a cassette tool. It's not expensive or hard to find, but there are numerous versions available based on what type of cassette you have on your bike, so you need to make sure to get the right size, or it won't fit. Which brings me to my next point:Something I love about bicycles is that they are fairly simple, mechanically-speaking. Because of this, hundreds, if not thousands, of different companies across the world have created their own bicycles over the years. The problem is, this has led to a vast array of components and sizes being available, none of which are compatible. When searching for drivetrain components, I learned that there are three primary brands/formats: Shimano, Campagnolo, and SRAM, none of which work with parts designed for another company's format. To make the choice harder, no one version is objectivelythan the others, so it basically comes down to which one meets your needs for the best price, and which name you like best.There are also factors like the circumferences of the tubes that make up the bicycle frame. This size determines the specifications of numerous other components you have to get, so it's very important to know it when buying other parts, or nothing will fit. It's basically a rabbit-hole of specifications and sizings, all of which are metric.In spite of the headaches caused by trying to stay in-budget and making sure everything I found actually fit together, it was a great experience. The hunt for parts was fun - I knew exactly what I wanted, and finding the exact right parts was like putting together a puzzle. Also, it made me confident that I have the tools and knowledge necessary to fix and maintain by bikes.More than anything, working hard to create my bicycle made me appreciate her far more than if I had purchased her from a bike shop. I know each and every part on my bike, because I hand-picked them all. The end result was the nicest bike I've ever ridden, let alone owned - a touring/commuting steed with a vintage feel, named Amelia. She's one of a kind, and she was made for me.