ratios

Hi there, Just purchased a pre-built 80Cc motorized bicycle off craigslist. The lady whom I had bought it from had had about half a tank in it already, so I didn't put in the first tank. When It came time for me to put in the first tank, I went to the gas station and purchased a 1+ Gallon...

I've got my 49cc mounted on a bike with 26" tires. Currently I have the stock rear sprocket but am going to put on a 60T when it arrives (I'm 240lbs and we've got hills here...the current one is pretty weak for torque, pushing my bulk around). I was considering replacing the rear tire with...