hello. i need to know a proper 1/8 mile gearing set up. the tire in the back is 11/6-5,
chances are the same types of people will answer in this thread, as in the other and with the same questions for you...
http://www.oldminibikes.com/forum/general-minibike-talk/87034-drag-bike.html
a proper gear set up for one (lets say a 40 hp motor), would be different than a set up for another (say 20 hp). i am more familiar with "big" cars, but would be the same principal. some of those higher hp/tq bikes can do 90 mph in the 1/8th... that gearing would prob be different than something with much less torque.
what is your goal? proper gear set up for what (top speed, time)? also there is a section somewhere on the forum, "la drag bikes" or something like that... they talk about that kind of stuff and motors etc... they are pretty competitive though, so dont know that they put much out there are far as the gears they use etc.... but may be worth it for you to spend a few days going through that thread... if you search, there are a ton of threads, with a persons setup and how fast their bike was etc.
i dont know what "fast" is for you, but to go pretty fast in the 1/8th you will need some power/torque. you can use the speed calculator i posted in your other thread to gauge what you will top out at (but who knows when you will top out, could run out of room, before that point)... but to put that power to use in the 1/8th you will need some good power/torque... there are guys with 40 hp motors that do real well in the 1/8th. im trying to keep myself from building anything that drastic for a minibike, as i have a race car to build... and that stuff gets pretty pricey! I have around $1000 in a motor i built for a mini bike project and im not even sure that will be "fast enough" in the 1/8th... for that reason, i dont try to gauge fast, i try to gauge FUN...
in the other thread you said you had a stock ungoverned clone? 7-9hp? if your bike tops out before the 1/8th, with that 12t/70t combo you have, then change the gearing until it tops out right at the 1/8 mile line or just beyond... (either go up teeth on the clutch, or go down teeth on the rear).
if you do not have proper parts in your engine, then I would not be running it hard at all... or changing gearing, etc.
all just my opinion