I have the same bike that I am in the process of modifying. I am actually cold forming the rear to fit 120mm wheels instead of going to 130mm because I already had a new set of 120mms laying around. I could use help though with the bottom bracket. How is it threaded and what size is it? I would like to replace it with a cartridge type bb but I am unsure what to replace the original with. I will also be doing the crank arms so the spindle type does not matter. A link to a compatible replacement would be appreciated.