Jim, I did a quick "low sprocket/low pivot" model in some of Tony Foale's software. I took the default settings for a simple "damper near the axle" model rear suspension with 133mm of travel. The rear ride height is shown as 830mm and the CG height as 650mm. That shows that 1G acceleration without anti-squat being considered. That changed rear ride height to 764mm and CG height to 618.5mm. Factoring in the anti-squat on that default model had rear RH at 790 and CG at 630 so you can see it kept the bike from squatting so much.
I then dropped the pivot 100mm and the sprocket height 130mm to keep a somewhat similar relationship of the chain. For this version the RRH is 830 and the CG is 650mm (no change). With the 1G accel no anti-squat is 764mm and 619, with anti-squat 777 and 624.
Even though the rear now squats an additional 13mm the CG doesn't drop as much because the front is presumed to stay topped out under acceleration.
830-777= 53mm, and again, this is from a "full droop" reference position.
I have little doubt but that juggling the pivot/sprocket locations might be able to improve things for either model, though the caveat with the anti-squat is that "improved" doesn't always mean the same thing to all people/uses. GP bikes often have adjustable pivots and they use that because the squat geometry will vary with sprocket size changes. But I don't think they normally change more than +/1 1-2mm at most once they find a relatively sweet setting.
To get a similar chart on the wheel rate the low pivot damper needs to have the top mount moved about 50mm forward, which is some but not a huge amount.
You are thinking of Horst Leitner's ATK sprockets, and that does actually reduce the variance in squat geometry a significant amount on a long travel dirt bike. There's less variance to cause problems on short travel so the net change there from the ATK is not as great
A commuter bike with 8 BHP that never exceeds 45mph can probably work adequately with an amazingly wide range of settings. You could even go with a hard tail, eliminating chain geometry concerns, and use a cushy seat instead.
My concern is for people who start hacking away when they have little to no idea that what they are proposing to do has any effect at all. A crash at 45mph can still put you in the hospital or morgue. The 8 BHP engine may not have enough torque to cause significant loss of ground clearance even with hugely pro-squat geometry, but it is always good to do some research first and try to get at least a mid-level "OK" design. If you've made things so the bike can't ground when leaned over at full bump, you could still have problems if the pro-squat bottoms out the suspension while leaned over and the suddenly infinite wheel rate causes a loss of traction.
beatr911, keep in mind that it was just a few laps on a different bike. The track is very short so a lap is about 1 minute. I looked through some old emails and found these comments where Arthur said "BTW, Emo thanked me for the spin on the bike, and said he could easily get 5 seconds a lap with minor changes. I believe him; he's a seriously quick rider. He wasn't specific about what these changes were. I will ask next time, especially if I can get another rider to test it." and "Given that proper racer Emo can do a 1 minute lap on my bike 5 seconds quicker than I can" and "I thought when other guys said they were impressed at my being "only" 5 seconds off Emo's time that they were just being polite. . . " but 5 seconds off the fast guy's time was respectable. So the fast guy hops on, reels off a respectable time, and says he could get another 5 seconds off.
Arthur's Kawasaki has a stock engine and doesn't run super-sticky tires as Arthur isn't interested in putting the money in it, he'd rather spend it on more track time. Other than the FF riding position the only real chassis change is the swing arm extension, so it probably is safe to say it will have performance much like a stock EX500.
The important thing IMO is that Arthur's bike shows that an FF riding position doesn't necessarily preclude riding in a respectably sporting fashion. And having a respected "fast guy" go out and come in saying he'd like to ride it some more adds some street cred to offset those who'd dismiss it out of hand.
One of the FFers was doing a Yamaha TMax with a Hossack FFE on it:
http://www.bikeweb.com/image/tid/101
And with that, I'm back to the garage to see if I can get things mocked up with wheels and the new cellulose composite chassis parts.
cheers,
Michael