I'm just putting the polishing touches on my bike now (installed a chinese two stroke, 67 cc kit). The problem is that my commute to school (well actually back from it) involves a couple of hills which require full throttle to get enough HP to get up them. My understanding is that this is pretty bad during the break in period. I've been following a couple of the threads on expansion chambers and have a couple questions. First, would you reccomend an expansion chamber for the middle or upper end torque. Seems like as I'm going up the hill I tend to be in the mid RPM range. Second, as you answer the first question can you point me towards a cheap source of decent chambers of that type? Thanks in advance!