can i ask where you got most of the parts? axle bearings and brackets look like northern tool. i want to make as much of this as i can. All gokart parts. I buy all my gokart stuff from
www.bmikarts.com . Best prices I can find and has everything. Don't get to caught up in the stuff they list as "drift trike" parts. Its all gokart stuff, thats just marketing in action. Check out their clearance page, I've snagged some great deals there.
I'd love to find the dimensions and tooth count and make my own sprocket too. Where do I start with this though? I use a program called Sprocketeer. You can download it here
http://www.idleamusements.com/?page_id=54 . It awesome for making your own sprockets. Problem is getting the axle hole completely centered, cutting a good keyway and cutting a good hole with plasma. I bought all my sprockets for these reasons. I would suggest doing the same.
I'd like to piece it all together after the frame but how will i know if the frame is too short or too wide for the axle and wheels etc. I bought my axle and wheels first and then built the frame for this reason.
Also what angle do the front forks go on? I eyeballed it and guessed

. They ended up at 52 degrees. This is directly related to how big your front tire is and how high you build the neck. So yours will probably be completely different. Not sure what is technically "correct". I was more worried about the way it looked than the way it worked (fortunately it worked too

) . Tire to foot peg clearance is the most important concern since you have to turn the bars completely sideways to slide through a corner. 2 wheel motorcycle steering angle or "rake and trail" is interesting stuff, if your interested.... If you want to learn more about it, here's a good explanation
http://chopperhandbook.com/rake.htm.
I just happen to have some 1.25" square stock laying around. 16 feet of it. I think that's enough for most of the frame. The two main frame tubes are long, I think you'll need more to finish it.
where do you get the tires? Gokart rear tires and wheels. What makes it a drift trike is shoving a giant piece of PVC tubing around the rear tires before you air them up. The ID of the PVC has to match or be a little bigger than the OD of the tire. Basically your just sliding around on PVC, the tire just holds it in place once its aired up.
fat tire? I bought a fat tire Mongoose mountain bike off Craigslist for $75 and then starting cutting! The more important things you'll need for the neck are the cups and bearings, so be careful taking the bike apart, the bearings are just sitting in the cups on cheap bikes. They are not sealed and will fall out everywhere. Most people use the bike neck but I had some 1.5" tube that fit the cups and bearings perfectly so I fab'd my own neck. I think it was .065 wall but that will depend on what bike you end up using.
seat? Tractor seat baby!!!

from tractor supply. Nothing more comfortable than your grandpa's tractor seat. Tractor supply sells this one with the cover. Works perfect and looks pretty darn good (doesn't look like a tractor seat!)
as you can tell this is me jumping wayyyy out of my comfort zone on this one. Thats how you learn! "Measure twice, cut once" and always mock everything up with tack welds. I've knocked more tack weld apart to change stuff than I'd like to remember.
Tons of DIY drift trikes on the WWW. I looked at hundreds before tackling mine.
Have fun! Post pics!