27 tooth pulley on a 883, 29 tooth pulley on a 1200. 883's come with a 27 because they don't have the power to pull a 29. Larger front= slower acceleration, more top end. Smaller front = quicker acceleration, less top end, all else being equal.

 

The gearing thing (883 vs 1200; 27 vs 29 tooth) presumes you can red-line in top gear. The bike in this dyno was taken to about 6500rpm easily...with the 27 tooth sprocket that was faster than a stock 29 tooth 1200.....

http://www.head-quarters.com/html/100_x_89.html

[IMG]local://upfiles/32069/59F3B9989F284A2EB6E9928E0FFCF70A.jpg[/IMG]

 

All things considered, the 883 gearing would be quicker off the line than a 1200 with the same mods. But in the end the 1200 with those same mods would be faster in the long run.
When you are building an engine you need to know if you are looking to be "fast" or "quick" before you even start. There's alot different approaches to each one. It all depends on how big your budget is.
In Sharley's case, he achieved both but judging by his dyno sheet, he had a sizeable budget to work with.

Edit: There is no doubt in my mind thatSharley'sbike would shock many a rider in a straight line race.

 

Dyno's are great for producing Hp & Torque numbers but don't really factor in rider load and headwind drag when you are talking about achieving max top speed in the real world.

 

Okay. Many good replies, lots to gleen, here is some more;

Ignition with rpm.
With the 45* V-twin engine you don't normaly see ignitinos with rpm over 7k. This is becausethe piston speed at the wall of the cylinder will be too much for any oil to keep it lubricated. The friction will kill the engine life.
Machines like the Vrod get arround this by having a much shorter stroke and larger bore. The bore keeps the HP up while the stroke drops the torque. The short stroke allows the rpm to get up to 9k+. Same with 4 cylinder jap bikes, bigger bore than stroke, higher rpm, less torque, not as quick off the line in a drag but higher top end speed.

The gearing:
The 883 & 1200 share the same primary drive & transmission. What changes is the front sprocket of the final drive. It is 27 teeth for 883 and 29 teeth for 1200. The 27 tooth is faster off the line but top end speed with a 6k rpm is only ~113 mph. The 29 tooth can get up to ~125 mph.

Cubic inches gives more power. Normaly both HP and Torque.
In order to feed bigger cubic inches you need a bigger intake, in order to get the exhaust out you need a properly designed exhaust system. In order to burn the air fuel mixture you need a good coil, wires and plug.

The attached pic compares a 26 tooth Baker front sprocket with a six speed transmission to a 27 tooth stock 883 sprocket with stock transmission, the black line to the very left is the fifth gear of a stock 1200.This is to show that with a 26 tooth front sprocket & Baker 6 speed tranny you will be able to beet a stock883 off the line and go a bit faster than a stock 1200. Stock bikes have rpm limits of between 5500 & 6000 depending on the year.

[IMG]local://upfiles/48626/C0F706397B97469494C01D0769B8AC98.jpg[/IMG]

To answer the question/subject of the post:

RPM + HP = SPEED

speed can be defined as fast off the line or top end speed depending on gearing.

 

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