I'm still dummying up parts. Rearset brackets are on. Rear sets are in place with threaded rod for now. Just seeing how it all lines up.
So, I put on the +2" RYCA shocks along with an 18" rear wheel to pick up the ass end of the bike. Chopped up and braced the swingarm (to make up for the metal removed).Putting it all back together, I figured I'd do a bit of head scratching on the belt tension.
With the longer shocks, there is a fair amount of swingarm droop. Smarter folks than me tell me that 10-15 degrees of droop is a good thing, so that doesn't bother me.
What bothered me was the change in belt tension as the swingarm moved. Eyeballing the shocks, it seems like they have about 1 1/2" of travel. Because they are set partway up the swingarm, that translates to more than that for actual wheel travel.
I took my trusty belt tension gauge, put a jack under the motor, and lifted the real wheel. With about 10 lbs of push the belt moves about 1/4- 3/8".
All well and good.
Then i removed the shocks and lifted the swingarm/wheel to where it would be when the shock compresses 1 1/2".
Yolks! The belt becomes REAL tight.
Worried about killing the belt and bearings.
The belt will become tightest when the centerline of the two pulleys and the swingarm pivot are all in a straight line.
I wasn't even there yet. Just raised the swingarm/wheel as much as they'd move with the shocks bottomed out.
So, I loosened the belt tension a bit with the S/A up. Just to where there was 1/8" of movement with 10 lbs of push.
Shocks back on, and the belt is pretty bloody loose. Like over 1/4" with almost no pressure. And over 1/2" with 10 lbs of push.
Hmm
Wondering what the happy place is between too tight and too loose?

Thanks Dave.
I tried checking it at 'level' then looking at it at full extension. Wahoo is it loose. That's why I check at what I thought full compression will be (lower than level).
I'm prob going to go with 1/4" of slack with 10 lbs at tightest point, and just deal with however loose it is when it is loose.
Just bolts on!

Try all that with a chain that has no stretch , gave up. Made struts to replace the shocks to hold swing arm so countershaft & s/a pivot & rear axle lined up adjusted chain then bought tensioner from Ryca, he said it wouldn't work , then modified it and mounted it to the rear set bracket , works perfect, love my little Miller wire welder !!

RYCA online parts store in the bobber parts section
Powell Peralta Editon chain tensioner
Uses a skateboard wheel should be wide enough for the belt too
I didn't take very many pic of the build but I have several of the tensioner mod , must have welded & cut it off 5 or 6 times to get it right
Send you some pics have to find then
Works great even under hard decel & braking which is where it really matters, was upset having to add the weight back on to the bike but it was worth it !

But in this case it was a must do

Still haven't weighed it but  I'm guessing in the 310 to 320 lbs range

I ride everything like I stole it and being pursued , if I started drilling everything stuff would be breaking , nothing would last

What I built is street legal t/sigs , mirrors , horn and I light as I could get it and still stand up to being abused daily

Ruttly,
Holy crap that was a lot of pics  

Seems like it worked out. Buell used a roller tensioner on their later bikes. Seems like a good idea. Not exactly small and pretty, but if having a lot of belt slack is an issue, this seems like a good solution.
Sent a note to RYCA. I'm sure they sell a lot of +2" shocks. Kinda doubt all the folks do a tensioner. Interested to her their answer.
Thanks for taking all the time to send the pics.
Right now I'm just jazzed that I got my dead ass in gear and finished the swingarm on Friday and installed it.
Have to order some stuff for the rear sets. And the foot brake lever is right on top of the header pipe  
Just bolts on!

Where did you find a drill bit long enough to drill the S/A pivot bolt ?

McMaster Carr catalog

What a cool search that turned out to be.

Something I used when I ran a warehouse was
the Thomas Registers

You can look up
Products
Or
Manufacturers
Or
SumthinelseIcantremembernow.