Electric bike power

[MetalMan]

Been doing some thinking/designing and parts locating for my bike. It looks like the cost is going to be ~$300 on top of the ESC and batteries that I have already. Here is a parts list:
http://img.photobucket.com/albums/v1...bike_parts.jpg

As I stated in a previous post, this bike needs some major reduction, 16:1 for 30mph. The largest "spur gear" (sprocket) on the wheel is a 28t, so I'll be using that. That sprocket will mate with an 8 tooth sprocket attached to the output of the reduction unit. A chain of the same size as stock will be ordered, and this chain should handle a larger load than the stock bike chain. So far, it has a reduction of 3:1.

On to the reduction unit. I would put some mod 2.5 gears (or something like that) in the reduction unit, but those gears are just too darn expensive and would require more precision alignment. From SDP-SI I found "ladder chains" and matching sprockets, so I found a combination (11t "pinion" and 54t "spur") that should work well. The 11t sprocket will go on the motor (requiring either a sleeve to convert the 12mm shaft to the 1/2" ID of the sprocket or a new shaft), and the 54t sprocket with hub will sit on a 1/2" diameter shaft, which will be supported by bearings. This unit will give a reduction of 4.19:1.

That's a total reduction of 14.5:1, which isn't exactly what I'm looking to get, but an extra couple MPH won't hurt. Anyone have any opinions/crticism on this setup?