I don't know if this is the right place for this but I figure you are the right people to be asking.

Right now I have a GT Traffic 4.0 and everything is bone stock.

For the last month I have been visiting family back in America (I live in Japan) and have been riding an old Free Spirit road bike I picked up at a garage sale. I have discovered that I love the friction shifters and the drop bars.

I was thinking it would be cool to put drop bars on my GT with downtube friction shifters.

Currently the bike has indexed shifters and I was wondering if I would need to do anything special to put friction shifters or if that was even possible.

Is it as easy as just connecting the cables and doing some adjustments?

Pretty much cable attachment, and adjust. It's a lot easier to go from index to friction than the other way around (sometimes).

Short answer: dont do (try) it, too much hassle.

Long answer:
The drop bar wont exactly be a problem. You may need a new stem to accommodate however. As for your controls, you are looking at new brake levers and of course new shifters.

The problems start when trying to find drop bar brake levers with appropriate amount of cable pull, that will work with the V-brakes that you currently have on the bike.

As for the shifters, you will likely have to fab some type of downtube-mount system to hold the shifters. This wont be the easiest or prettiest. For hints on how to pull this off, check out some of the pictures from events such as krankworx or other jump/slopestyle events. Occasionally some riders will mount shifters to the down tube, to allow for bar spin tricks.

If it were me, I would forget about making the swap on your current bike and finding a new (to you) bike that already has the downtube shifters installed from the factory. Additionally, older bikes like you will be looking for will more than likely have drop bars on them already.

There is a slight lack of anywhere to put down tube shifters on your GT Traffic frame. as above, it's not worth it, too may parts to replace and fitting issues.

Also if you really want friction, you need to be looking at an old bike (15 years +), as most if not all road bikes made now are indexed with STI's (brifters) except the lowest end of the market ones. Would suggest you have a go with a bike with STI's, as correctly set up, they make riding a lot easier than with friction shifters

Thanks for the reply, I was worried that it would be a lot of hassle.

One more question: Would it be just as much hassle to go with brake/shifters like these with drop bars?

they will work just fine for you ,it what they are make for.

How do you figure it will work fine? Tarkin, it will not work fine as posted above you will need a lot of parts and $. For starters a road stem, the stem you have is 25.4mm you need a stem to mount road bars of 26mm or 31.8mm. Also cantilever short pull brakes or you will lock your wheels faster than you can say the eff word. So....
1. A stem that works on the bars you choose.
2. Bars
3. Bar end friction Shifters and levers or the Sora shifters you posted
4. Cantilever brake arms
5. Bar tape.
6. Cables

I have done it before and all you end up with is a race oriented trail bike more or less.

Yeah, that's what I was afraid of. The more I have been reading up the more I find that I will need to put on. Thanks for all the info.

So I appreaciate the information about changing shifters but I have another question.

I was thinking about trekking bars, like these, and when I talked to someone at the LBS they said that I would need grip shifters to go on the trekking bars.

Is that true? Or could my current set up (see first post) work fine?