Personally, I like the look of the second bike. Overall it seems to be almost solely a road bike, whereas the first bike can be used for bike paths as well. I'd mostly be riding it on roads (asphalt) but I'd like the option for bike paths also. From what I've read, disk breaks are generally more reliable than rim brakes. Bike 2 also has no front suspension.
Basically I need you guys to give me a reason to get the bike that I feel looks better over the bike that seems to have better specs.
Are the specs between the bikes negligible or is Bike 1 significantly better suited for my needs?
If most of your riding will be on dirt roads and paths, get the Transeo. If most of your riding will be on pavement, get the Tachyon, and don't let the thinner tires and lack of a front shock keep you off the dirt roads and paths should the need or desire arise. There is no rule that says you need fat tires and a shock fork to ride easy dirt. I do it on road bikes all the time.
At 5'9" you should be looking at medium sized (~17.5 inches) frames.
