optimal chain and sprocket setup question

[organ donor]

i have a 94 M900 that is in dire need of a new set of sprockets and i was just wondering what is the optimal setup for cruising twisty roads at around the speed limit (not what the yellow signs suggest but actually the legal maximum).  currently have 15/40 setup, running about 4.2k at 70mph. also, has anyone dealt with SOAP (Sum of All Parts)?  they have many sprockets available on ebay and the prices seem good just kinda new to all of this and i'm a poor broke bastard lol.

oh yeah, guess i should mention that the motor is pretty much bone stock.

[Slide Panda]

Optimal is really a preference issue. Stock gearing is 15/39 - many folks like something around 15/42 or there about. If you want more torquey grunt, then you might even go 43 or 44. I've got a FI 900, and run 15/42 which I find pretty good.

If you want to play with nubmers:
http://www.gearingcommander.com/

[Speeddog]

In 6th gear, you're within about 0.1% of the gearing that I have in my S4. 

My primary gear is a 1.84, yours is a 2.00.
I'm running 15/39 sprockets.
I like my bikes geared tall, biased toward highway running.
I can live with my first gear, pretty flat around here.

You've got the wide ratio trans, and I don't, so your first gear is lower than mine.

I'd leave it at that or go up to a 41 to get a little more driveline durability.

[organ donor]

thanks guys, that's exactly the sort of info i was lookin for,  love the gearing program