I have two Tee-Dubs that I picked up several months ago, both 2003s in near perfect shape, and each had only 250 miles on them. I bought two so I could take another person with me and teach my wife and 13 year-old boy how to ride. I decided to go to the dark side by putting a 52 tooth rear sprocket on one and a 55 tooth on the other (for those learning). Since I do some in-town street riding, I'd like to try doing a dual sprocket using my TW with the 52 tooth and add a 48 tooth. It seems like a simple job, but just wanted to get some tips from the experts in this forum, such as what to use for proper spacing for the chain, whether a recessed sprocket is required, safety concerns, and whether or not I need to get new hardware (nuts & bolts). I've seen several posts on dual sprockets with pics, but haven't seen a step-by-step guide. Any help is appreciated. Thanks!