Most of the time one single tooth on the clutch bell is about 2 teeth on the spur gear, About it's not always that way though

So the gear ratio of that would be absolutely crazy as long as the Pinion gear would remain the same. But if you change the pinion gear size then the speed could actually stay the same as long a syou made the right adjustment to the size, also the tire size also determins overal speed. The smaller the tire the faster you'll accelerate but the slower the overall top speed will be. But the larger the tire the smaller the acceleration will be but the faster overal top speed you will have.

There's a lot that determines overall speed, rollout is the best way to determine your speed. Actually if you know your exact engine's max rpm's or rpm's at a certain point in time you can tell exactly how fast your going that particular moment in time.......... Pretty cool actually