Alright so I've been riding arround madrid for a few days now and it's pretty difficult and cool. . . but today while I was decending this one hill, I heard this huge bang! then my bike suddenly started to slow down without me even trying (think a blown tire). So I jumped off the bike and looked at my rear tire and noticed my chain had a TON of slack. That led me to conclude that my nut had just came loose and my wheel just moved up in the dropout. NOPE not the case, so as I pull out my wrench to tighten the nuts I notice that the locking nut (the grooved one on the inside) just wasn't there! This is great because nuts are like the only extra part that I didn't bring

So enough with the story, I have a question. Where the fing hell do I get one of these? It's an IRO/Forumla hub and I really don't want to get the wrong one and have it break or mess up the spacing or chainline. So where can I get one where it wouldn't cost a buhzillion dollars for shipping? Any help would be worth its weight in gold. Thanks!