Hi,
I have a kfx 450r. I have recently purchased a " combo" chain/ sprocket from Sidewinder racing. I am relativly happy with them. I find that they work well together and I am satisfied with my top speed. I am currently using 15 tooth front and 33 tooth rear. I also have sidewinder top of the line chain. All my shifts are quite smooth. I am debating whether or not to go a step further. What I mean is that I am considering getting a new rear sprocket hub and installing something like a 27 tooth rear sprocket. Has anyone attempted this? Your all going to say that your grandmothers will be able to beat me to 60 miles an hour, and they will probably come close, but I 'm really keep on gettiing some serious speed. Has anyone experimented with this?

 

Why do you want to go that fast? The bikes suspension isnt good and handleling sucks at that high of a speed. Your bike was built to accelerate fast to 60, not go 120m.p.h

 

I am amzed that you havn't tried it too. I have posted this question on other sites and people seem to think that top speed isn't important. I don't find it that important to get to 60 in 5 seconds. 6,5 is fine for me ( just an example) but I want to be able to drive 70 miles per hour without being at red line. In my county atv are road legal. I drive it quyite a bit at 65-70 miles per hour. With my new set of sprockets I can drive withoput burning out the engine. It's quie fun too. For your information I don't think I am going to pursue ( just yet) my goal of being able to get to 95 miles per hour. There are two reason 1) I don't think there are tires that can handle it 2) I cannot find a rear sprocket hub that will allow to install something like a 27 tooth sprocket.

What kick can I get out of my atv if I do a big 3 modification and I realize I get wheel spin all the way to 60 miles per hour.. What's the point in doing something like that if you cannot use the power? I personally find that all the atv should be gear much higher.

 

Well if ll you do is road ride it yeah i guess its ok do put sprockets like that on it. Butr i wouldnt go any higher. nor do i think that they need to come geared any higher from the factory. My yfz is just fine. It was built to be fast from 0-60 and have great acceleration not go 85.
Plus if you know how to ride it you won't spin all the way to 60. Especially on blacktop.

 

i dont think the speed is going to be a big issue i wonder how the transmisson would hold up

 

One of the rerasons you probablt never minded your gearing is that the stock gears on the YZF are higher than mine. I have a friend in town that has a YZF. The only time i get some distance on him is at the start after that he's gone. His accelerations past 50 km/h ( 31 miles per hour) and top speed are much better than the KFX. Alot of people feel that the KFX is geared too low. To be total honest, I should have done much more " homework" on the diffrent atv's. If I could go back in time I would not have bought a KFX. They look good , handlle fine, are quite torky in the midrange. But that's all they have. I think they are the bottom end of the 450 cc atv.

 

how can a 15 tooth front sprocket and a 33 tooth rear sprocket affect the transmission. Funny you mention that because I think I have a problem with my clutch.

 

If its geared too high that could strain your clutch. But i wouldnt think it would hurt your tranny. GOOGLE KFX450 TRANNY and see if there are any problems with them.
Also try
<u> http://www.kfx450central.com/[/U
they have good info on them.

 

If that is what you want to do go for it you can always go to a bigger front sprocket it is allot cheaper and you can also invest in larger back tires this will help your top end speed just make sure you don't go to high in your gearing or your bike won't be able to pull the gearing in top gear. And it will make your bike a slug. I would do my homework on the rite gearing and tire size for your motor combo and hopefully you find something that works for you.
On my Busa bike it cost me allot of money to find the rite setup to run but hey it is geared to do around 150 MPH and it comes out of the hole like a rocket. Gotta Love it :0)