High Speed Gearing

We are racing Vegas2Reno and I was wondering if any of you have experimented with the gearing for wide open fast stuff. Anybody else racing V2R on their yamaha? By the way this is for an 06yz450f.

I would think a 14/46 combo would be killer for that. It's basically wide open desert, right? You could even use the same length chain with that gearing. :thumbsup:

Stock gear ratio is 3.69, the 14/46 is 3.28. That'll stretch out 5th. :ride:

I was trying to do a search for some sort of "gearing tutorial". What does the gear ratio mean? What's the difference between 3.69 and 3.28? How do you get that #? Sorry for the questions, I haven't given gearing much thought, I just know you have to change it for whatever type of riding you are doing.

Idk about the aluminum frames but i know you can get a 16 tooth up front on my 400f

I own a 15 tooth and that with a stock 49 rear gets me up around 90 topped out.

There is a company called either specialty sprockets or sprocket specialists that will make you and custom toothed sprocket.

then you cuold run a very small rear, but you may have to modify the chain guide.

Also, I do not recomend going that fast offroad w/o a steering stabilizer, you might end up regreting it, after you wake up in the hosptal a couple days later.

I was trying to do a search for some sort of "gearing tutorial". What does the gear ratio mean? What's the difference between 3.69 and 3.28? How do you get that #? Sorry for the questions, I haven't given gearing much thought, I just know you have to change it for whatever type of riding you are doing.

You get the number by dividing the rear sprocket tooth count by the front sprocket tooth count.

14 front, 46 rear: 46/14=3.28

The higher ratio number, the lower your gearing will be at the rear wheel.

Also, I do not recomend going that fast offroad w/o a steering stabilizer, you might end up regreting it, after you wake up in the hosptal a couple days later.

I race alot of desert so have the GPR, desert tank, etc...

Idk about the aluminum frames but i know you can get a 16 tooth up front on my 400f

I own a 15 tooth and that with a stock 49 rear gets me up around 90 topped out.

There is a company called either specialty sprockets or sprocket specialists that will make you and custom toothed sprocket.

then you cuold run a very small rear, but you may have to modify the chain guide.

Ya....I would like to have the bike top out at 100+....not saying I will go that fast but it would be nice....so I can keep up with Hengeveld :thumbsup:

At the Duquoin Mile, we ran 15/36 for about 115mph('05 4 speed) Tdub

At the Duquoin Mile, we ran 15/36 for about 115mph('05 4 speed) Tdub

So with the 5 speed....does that mean we would get more top end

So with the 5 speed....does that mean we would get more top end

Depends...realize that it takes Hp to pull tall gearing for top speed. A 50hp bike might not be able to pull that gearing to achieve that top speed. Theoretically yes...5th is an overdrive so with identical gearing it should go that speed...BUT will the motor pull it? The 5 speed came with a lower final ratio than the previous yrs, so basically an '06 and the earlier years will approximately have the same top end with stock gearing. Tdub

Assuming the ability to reach the rev limit of 11,500 in top gear (questionable in some cases), and no tire slippage (never possible, even on pavement) the gearing works out like this:

A stock '03/'04 450 has a theoretical top speed of 89.4

The stock '06 has a theoretical top speed of 95.2 mph.

The suggested 14/46 would yield 109.3

More to the point, the higher gearing would yield 13% lower RPM at a given speed in 5th than with the stock gear, which could be quite important when running fast over a long distance.

As Tryce points out, ultimately the top speed issue becomes a question of whether you have the juice to pull the gearing. His 15/36 gives him 13 mph/1000 rpm, or 149 mph at 11,500. At his terminal speed of 115 on the mile, he would, without tire slippage, be turning just under 9,000. I'd guess 15 mph of wheel spin, which would bring the revs to right at 10K.

...And as the power starts to fall off at 9500/10K, no reason to gear any differently for high gear :thumbsup: Tdub

Who sells the smaller rear sprockets?

Im lookin for a 44 or smaller.

How heavy is the rider? He better be aerodynamic!

I bet mine will go fast with just 130lbs on it! :thumbsup:

It's been my experience that you can get them from many of the normal sources, but below the cataloged sizes, they are special order items. Tag Metals will make it for you, and often charges very little extra for it.

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