Hi, I am considering overhauling my five speed, department store bike to a singlespeed. I would greatly appreciate any serious advice for upgrades while keeping in mind the low cost of the bike itself. I am not looking to make the bike something it is not, I know that it is relatively inexpensive, and that my use of the bike would be for casual riding. That said, the bike does have a great frame and maintains speed rather well. Below is a list of potential improvements that I would consider. Frame is made in Japan. Research on the company reveals that Road King was a Canadian Catalog Company, that sold bikes similar to Schwinn.

Please keep in mind:

• I am taking this on as a project to learn more about bikes (beginner status)
• I won't benefit from suggestions regarding ditching the bike and starting new, that's not really the point of this project, time is not an issue
• I live in a city where bikes are stolen frequently, so balance of cost and benefit is important

Okay, list of possible improvements (what's necessary?)

• New Wheels: Rear wheel hub is too narrow, 5-speed shimano freewheel setup does not allow a simple solution. I can't use spacers like i could with a freehub, I believe (current wheels are stock, but straight). Current Wheels are 26x1 3/8". Spacing is 128/130 mm rear, 90mm front
  
• Bottom Bracket: Current bracket uses terrible, stuck, cottered cranks, crank itself has a slight wobble so I would like to swap the whole bottom bracket
  
• Pedals, Handlebars, Seat: Questionable on all acounts, worn pedals, saddle is what i call the "fanny seat", too wide, handlebars are stock
  
• Paint:I've put a bit of time looking into taking on the task of painting this, I know it is time consuming project but I actually have the bike completely disassembled now as I consider the other upgrades
  
• Fenders/Accessories: I already took off the chrome front and rear fenders, and huge kickstand.

I know there is a bit of work that could go into this. Obviously the simplest thing would be to loose the derailler and just utilize the smallest cog for the single speed. Goals here are to improve the ride, lighten everything as I have to carry this up and down 2 flights of stairs everytime I use it, and to transform to some degree an otherwise worn bike. Thanks in advance to all serious responses!!!

Oh, parts and brand suggestions are greatly appreciated! Especially for wheel suggestions. Painting advice or advice on all acounts is great.