600 ice gearing question

[1xr]

I don't know what to run for gears on the ice in 660, with my picked speed track.
21-40
21-41
22-40
22-41
Also does anyone know if all the above gear options, I can use a 70 pitch chain, I think thats my stock lenth chain.

 

[Srxspec]

Running the sled at 10,800 on the tach.

1:1 clutch ratio & MAX shift for a stock Yamaha uncut primary.

21-40 = 99 mph @ 1:1 & 104 mph @ max shift

21-41 = 96 mph @ 1:1 & 101 mph @ max shift

22-40 = 103 mph @ 1:1 & 109 mph @ max shift

22-41 = 101 mph @ 1:1 & 106 mph @ max shift

I'd run around that 1.9 area probably (close to 21-41) if running ice drags. I believe that would use a 68 link chain.

22-42 would use a 70 link chain and be good for 98 mph @ 1:1 and 103 mph @ max shift.

 

[Srxspec]

Here is a link to an interactive gearing chart I have put up in our section. You can determine the clutch rpm and then use that in the gearing portion and choose different gears.

http://www.ty4stroke.com/viewtopic.php?t=33188

 

[1xr]

Running the sled at 10,800 on the tach.

1:1 clutch ratio & MAX shift for a stock Yamaha uncut primary.

21-40 = 99 mph @ 1:1 & 104 mph @ max shift

21-41 = 96 mph @ 1:1 & 101 mph @ max shift

22-40 = 103 mph @ 1:1 & 109 mph @ max shift

22-41 = 101 mph @ 1:1 & 106 mph @ max shift

I'd run around that 1.9 area probably (close to 21-41) if running ice drags. I believe that would use a 68 link chain.

22-42 would use a 70 link chain and be good for 98 mph @ 1:1 and 103 mph @ max shift.

Thanks for the info, it will be helpful.
I was going to guess a 1:90 to start with and have nearly 100 without useing overdrive, I try not to use overdrive in 660.
Are the tachs out a few hundred too high at the top?
Will a stock apex run in the mid to high 90's in 660?