Before it all starts, I want to get this clear for everyone:IT'S NOT FOR EVERYDAY TRAIL USE, and I want to achive this simply by playing with the sprockets.
I'll give it a try once, to pass a 400yzf and a 400 scram with huge speed difference. I don't think it would be too much of a waste, since taking the stator cover is a "daily" maintenance, and changing sprockets is easy, and they don't cost an arm and a leg.
What size of sprockets should I use? And will I be able to pull such a big gearing?
Or does anyone know the primary reduction ratio. Using the formula from armyman, I could have an idea of my top speed...but I can't find the primary reduction (before the gears).
One important question...will the tires hold on, or will they explode from centrifugal "pressure"?
I just want to do this for fun. A one time try.

Thanks (see my mods right under)

 

You can try ...thats for sure.
I'm no drag racer...But I doubt you are going to achive this with just sprockets. The bearings might have trouble with that along with alot of things...including the suspension....I would use a street tire too. I think you might balloon a normal offroad tire.
Give it a try and let us know. Just don't kill yourself in the process.

Seems there are a bunch of guys in the forums that strickly drag thier bikes. I do not...so I'm just guessing.
good luck.

 

Never gonna happen Zorro! My mods must have really scared you...and we havn't even seen the results yet! I tell you what...since your low end power will suffer tremendously we could use the sling shot method: I will attach the yellow tow strap to your Shee, pull you with my amazing low to midrange and then when your powerband hits, you disconnect! That could actually be fun!

Seriously though...I can't wait to see the results!

 

fmf,
Thanks for caring ("don't kill yourself"), but, don't worry...before I do this, I will be sure the bike can handle it. And if the mods I have to do to play safe start costing a lot, then I'll forget it. Why do you think the suspension or bearings would have a hard time? I think they are supposed to turn fast easily...and the place I'm gonna try (if I do it) is flat with no bumps...just smooooth...so I wouldn't think the suspensions would break.
Just started thinking about it a little.
Assuming original top speed is +- 70mph, I have to double the gearing (original sprocket ratio is 2.9 -41/14-...I should get 30rear and 20 front(!) to have a 1.5 ratio, that would theorically double my top speed). I don't know what the biggest front sprocket for banshees is. Neither the smallest rear.
Street tires.mmmh. Don't know. 10" tires are crap tires...and I'm not even sure they can handle more than 100mph.
Please drag racers...advice!!
The tire explosion is the #1 problem. Don't wanna ride 100+mph on rims!!
The towing up to speed method sounds nice

 

It's going to take a lot more HP. I forget the exact amount, but the equation for speed/hp and drag coefficient when wanting to add more speed is like 2 times speed = 4 times HP

Sounds like it's time for a turbo.

 

Hi this is Dustin my dad and I drag race we just started last year my dad is runing 16 gear on front and stock on the back this year he is putting a 17 gear on the front I think that is as big as you can go on the front dont know about the back. The mods my dad had last year with the 16 gear on was Toomey T5s and a set of Vitos Super Stock pistons that's all he had last year and know he just bought a cool head with 21cc for trail riding and 18cc for drag racing and a hot rod crank. When he put Vitos Super Stock pistons in it gave him lots of power he could almost let the clutch out with out giving it gas with a 16 gear on and by the way he only had 95 psi. in each side it was supose to have 130 pis in each side. He ran all summer like that with a 16 gear.

 

You want 125 mph out of your quad? Try dropping it off a cliff. It will be cheaper than getting 130 hp out of it, which is what you'll need to go that fast.

 

Probably the easiest way to take your Banshee 125 mph is to hold on to the back of my R1. 125 mph is about the time I'm shifting out of 2nd gear!

Bart
www.members.home.net/bartkim

 

It is not possible with a stock motor. Even if you geared it right, you would not have the power to pull the gears. Speed is directly related to engine power. I cannot recall the exact formula, But you are required to have x amount of HP to be able to do y amount of mph..

 

I dont know man........pretty crazy

You would probably have to cut your case so you could fit such a gear and do other small stuff like that, plus your chain would be so long.

I wouldn't do it though, something could go wrong and you might end up dead. your steering would probably go out of whack and wobble and,,,, well just think about that, pretty sick.

I dont think it would be worth it even if you did manage to pull it off perfect..... but what if you didnt over such a thing like that. no worth the risk!