5. Before we knew how long each tube needed to be, we had to decide on inner axleshafts. Nitro Gear & Axle is the official gear and axle of Ultimate Adventure. We went through the company’s listings of axleshafts to decide on an off-the-shelf set of a chromoly 15.96-inch Dodge short shaft and a 38.06-inch chromoly long side shaft from a ’94-’99 Dodge truck. With these known lengths we could determine how much tube to allow on either side.