Sometimes I get so focused on one thing that I forget about the other parts of the project temporarily. But it is important to be sure that the rear end of the cart will work well with the front end that we spent a lot of time getting just right. There are a number of ways to set up the drive train on a rear wheel drive vehicle. I don't believe I have seen a front wheel drive go cart yet. You can go with a solid axle design, rear swing arms, trailing swing arms or possibly a combination. You may ask which drive train design is the best? I may ask which type of coffee maker is best? It depends on personal preference, cost, as well as performance considerations. Do we want to go fast or are we more concerned with torque and climbing ability. If you asked a kid, "what is the most important aspect of a go cart?", what do you think they would say? When I was a kid I would say what is an aspect. Most kids would say it's gotta be fast. I don't mean to disappoint you but speed is not one of the considerations for this project. This will be a rather slow beginner cart. I want it to ride very smoothly and have enough power to do a little climbing. If you ask me about the most important aspect of any vehicle I will say the brakes. Speed without brakes is kind of like neglecting to carry enough fuel in an air plane for the trip across the ocean just to increase the travel speed.
I have decided to go with an independent swing axle design. The first thing to do is determine how long the swing axles need to be. There are a number of design considerations for the drive system. They include,
1. Track width ( How wide between tires)
2. Drive sprocket size
3. Axel Bearings
4. Flexible Drive joints ( u-joints or cv joints)
5. Axel length.

This may sound a little involved but like anything else it is not that complicated if you break it down to one thing at a time. According to the CAD program there should be enough room for everything to fit and have an overall width of 52" from outside of wheels. The following photos show the swing axle design. This is the overall dimensions of the swing axle.

This next photo shows where the swing axle fits in the rear of the cart.

The next photo shows an item that has been used in lightweight power transfer applications ever since mankind switched from square to round wheels. It is called an Azusa Bearing Hanger kit. It consists of a bearing that floats inside of a flangete which is bolted to the hanger. The hanger is welded to the frame at the appropriate location and holds the axle in place so it can turn the back wheel. They come in all sorts of sizes and configurations to suit most any set up. Granted they are not designed for automotive drives but they work quite well for go carts. I am not sure if they are named after some inventor or if someone said Hey, lets named this something that is hard to pronounce. It is very simple and very functional. I love it!

Earlier I spoke about fixturing as a way to produce accurate and consistent parts. The front suspension components were more or less free handed using chipboard patterns because any inaccuracy could be adjusted. The rear end will not be quite as forgiving so we will first build a fixture that will hold the parts in place until we can tack them together. Both swing arms will be exactly the same so building a fixture will ensure that both sides will be identical. The swing arms will consist of 3/4" tube for the arms, Azusa bearing hanger,1" Schedule 80 pipe for the pivot bearing housing and nylon pivot bearing inserts. Here is a picture of the fixture set up to hold everything in place.

The pieces are held in place using C clamps until everything is tacked together. The bearing hanger is welded to the outside and the 1" heavy wall pipe is welded to the other end. I got a little ahead and of myself and cut the center portion of the bearing holder before taking a picture of it. You will want to leave it whole until the arms are completely welded so that nothing will move out of place. You will find that parts tend to squirm around when you apply four or five thousand degrees F. of heat.