I purchased my first fixed gear bike on ebay. And boy do I love the feel of it. But the problems I have met with this bike are pretty numbered. Basically, I have a little bit of "dead space" when I peddle. That is - there is a little bit of movement where my peddles can wobble but my back tire can not, and it is driving me crazy. One friend suggested it is because my "bottom bracket" is loose. Would my bottom bracket affect that? If so how much would a shop charge me to tighten my bottom bracket? It also my be that my chain sags a bit even when I have my wheel pulled all the way back. Lastly, it might b e that I don't have a lockring on my bike. Infact, being the neophyte I am, I didn't even know what a lockring was until my cog fell off my bike (I am in the order of getting one now). So please help me, why do my peddles ahve deadspace? Sorry for junking up your forum with petty questions but I truly want to enjoy my fixed-gear bike to the maximum and I did a fair bit of googling before posting. Thanks.