So im thinking about ordering a performance exhaust as my first upgrade for speed...which one do ya'll recommend? Im new to motorbikes... http://speeddemon.ca/motorized-bicycles/parts/expansion-chamber-muffler-black.html or http://www.sickbikeparts.com/catalo...ducts_id=83&osCsid=bq87168lco01opqhfgde99s423 plus i currently own a thruster fixie (http://www.walmart.com/ip/Thruster-700c-Men-s-Fixie-Bike/17206771) it comes with an extra 18 tooth sprocket attached firmly to the rear axle so i was wondering if i could attach the motor chain to the 18 tooth instead of the stock sprocket that comes with the motor kit?? ( i know i would have to take off at a greater speed but it would be better than killing my spokes>) Thank you!!! very Much Appreciated!!!!