I assumed I would put the lower shock mount at roughly the same distance from the swingarm pivot behind the motor as the stock Sportster unit, as I was intending to use a swingarm of stock length. Now I just needed something to attach the bottom of the shocks to, something like say...a swingarm. The stock arm was out of the question, weight-wise. This frame is of an antique design wherein there are cast lug joints with tubes sweated into holes. Most likely oven-brazed, but I couldn't say for sure. The stock swingarm is of this design and somehow ends up with a lot more casting than tubing, so weight suffers greatly. One of the small design errors I will readily admit to on this project was my commitment to keep some of the classic "cast" personality of the swingarm. To do so, we retained the front 2 inches of the original swingarm, the pivot area, which houses twin tapered roller bearings. Whatever attached to the rear wheel and shocks would be married to the original cast pivot area.