Singlespeed & Fixed Gear - Trying to figure out my gearing...

I recently got a Dawes SST AL as my commuter. I use it as a freewheel'd single speed, not fixed. The problem is that i feel like im spinning too much once im on a smooth open road. Its currently a 48:17 setup. Im debating getting a 16t freewheel but am worried it will make no worthwhile difference. Any opinions on the matter? moving from a 17t to a 16t freewheel?

Or should i just get like a 50t chainring? which will require a new chain as well. And which ring would you suggest? its just a budget bike. I prefer to spend the real dollars on my mtb.
thanks for any advice.

Changing the freewheel by one tooth will make quite a big difference. I think with a 48t chain ring, dropping a tooth on the freewheel is like 4 gear inches. http://software.bareknucklebrigade.com/rabbit.applet.html

check out that site and play around with different setups.

http://img133.imageshack.us/img133/2102/fixedgearingcharttr8.jpg

There will be a difference. Not huge but definitely noticeable.

Gear inches = Chainring tooth / Cog tooth x Tire diameter in inches.

Common tire sizes in inches.
700x23c = 26.275
700x25c = 26.375
700x28c= 26.575
700x32c= 27

Example: 44 / 17 x 26.275(23c) = 68.005.... round it to the nearest tenth and voila!

How much is "too much spinning" ??
With a 48-17 you'll be doing 25mph at 110rpm...
With a 48-16 you'll be doing 25mph at about 102rpm.

I bet he tops out at ~80rpm and feels too slow, so moving up a gear or two to higher his speed at ~80rpm.

I went up two teeth from my 16:48 to a 18:48. And it's a lot more comfortable, the switch was pretty big and I don't regret getting a 17t. You should be good jumping up a tooth.