SAT Motorsports rigid attempt.

[JamesS]

I recently came across a bike that was partially 'assembled'.
The guy got a buncha parts off the internet and tried to build a chopper around an SAT frame.
He seemed to have a little game as the handlebars have been fabbed and will most likely be used. However he had little knowledge of the wide tire bike genre.
This was evident in the rear 250mm tire/wheel bing offset to the left as he tried to line up the final drive sprockets.
He then passed away , his family having no idea what to do with the bike.
So I go it for a good price , tons of parts , an extra engine and a buttload of engineering problems.


Looks pretty good! However these parts are very loosely assembled.

I began by disassembling the bike and checking the frame. There were some anomolys in the frame , none to tough to over come. Buddy had installed a .25" spacer between the engine and inner primary plate , this was going the wrong way.
I have built a lot of custom choppers so procedure is familiar to me. Centering the rear wheel , I saw that the sprockets were around .600" out of line. Checking parts and manufacturer sites I came to the conclusion that the stock trans mounting plate was not going to work. An offset plate , in conjunction with a PBI 1.31" offset sprocket will get things lined up.


I have a little experience with the wide tire stuff , but not as far as suppliers go.
Is there a trans mounting plate that moves the trans to the right?

[Shovel52]

Obtaining a plate would be no problem, but what would that do to the other side of the bike when you move the trans? They have double link chains you can research. Will adding another chain width clear all that? then experiment with some shims?
kind of hard to tell since your pic. is on an angle......muck I didn't read your post, I guess if you used an off set plate , you could offset the primary with it..

[STEINBVG]

RSD TYPICALLY USED STARTING AT 250 TIRE.

IT WAS DEVELOPED SO THE ENGINE AND TRANSMISSION HAVE NO OFFSETS AND ARE IN STOCK POSITION RELATING TO THE FRAME AND EACH OTHER WHEN YOU GO WITH VERY FAT TIRES. SO THE BIKE BALANCES CORRECTLY.
I DON'T BELIEVE THERE'S AN OFFSET TRANSMISSION PLATE TO THE RIGHT, BUT I'M PRETTY SURE IT CAN BE DESIGNED, OR EVEN PERHAPS RE DRILLED FROM A STOCK ZERO OFFSET PLATE. BUT WHY?

THE PRIMARY MUST CONNECT TRANY AND MOTOR W/O ANY ADDITIONAL SPACERS, HOWEVER, DEPENDING ON A MANUFACTURER OF OPEN BELT, YOU MAY NEED TO USE A BIT OFFSET MOTOR PULLEY TO COMPENSATE FOR THE THICKNESS AND MACHINING OF THE MOTOR PLATE- TO ALIGN IT WITH THE CLUTCH BASKET.[ I BELIEVE I USED .5 OFFSET WITH RIVERA BRUTO IV, BECAUSE OF THEIR THICKNESS[ MOTOR PLATE WAS ZERO OFFSET]

NOW.
THE REST OF ALIGNMENT IS BETWEEN THE TRANSMISSION SPROCKET AND THE WHEEL SPROCKET.
TYPICALLY THE RSD TRANY SPROCKET RUNS UP TO 1.5" OFFSET, WITH BIG OFFSETS IN INCREMENTS OF .25[ MOTORWAY ENGINEERING, VULCAN]. MIND YOU THE LSD BIGGEST OFFSET SPROCKET IS 0.9, TO FIT INSIDE OF THE CAVITY AND SOME FIT BETTER THAN OTHERS.

THE REAR SPROCKET ON THE WHEEL CAN BE SPACED AND SHIMMED IN SMALLER INCREMENTS- SO BETWEEN THE 2 YOU CAN ACHIEVE A PERFECTION[ INDEED THE WHEEL IS CENTERED AND YOU ALLOW THE CHAIN CLEARANCE FROM THE TIRE].

HOWEVER, THE THICK SPROCKET ON TRANY WILL NOT FIT WITH THE CLUTCH ACTUATOR- THAT ONE WOULD NEED TO BE SPACED OUT. IT HAS 3 MOUNTING BOLTS, 3 INDIVIDUAL 5/16 ID , I BELIEVE, SPACERS OF APPROPRIATE LENGTH FOR EACH BOLT WILL DO BECAUSE OF THE AXIS OF THE JOB IT DOES. NO NEE FOR FANCY MACHINING.

IF THE RSD FINAL CHAIN IS INSIDE THE FRAME- YOU SHOULD BARELY NEED ANY TRANY SPROCKET OFFSET, ESPECIALLY WITH A 'PUNY' 250 TIRE.

HOWEVER, IF THE CHAIN RUNS OUTSIDE THE FRAME, LIKE IN MY CASE- I HAD TO USE 1.5 " OFFSET SPROCKET. AND THE WHEEL HUB IS VERY EXTENDED FOR THE REAR SPROCKET.

[JamesS]

Thanks for the responses guys.
Please read the posts as to alleviate misunderstanding.
Thanks for the wide tire history recap too, I lived that era in the chopper shops I worked in. My inexperience due to the fact that the proprietors of said shops wouldnt allow the WT stupidity in their shops. I , we , all watched the drivetrain get pushed to the left into very dangerous territory , first offsetting the primary and tranny and then the real stupidity of offsetting the engine ,, primary and trans to the left. Some guys wiped out , experienced riders were having trouble with these silly bikes. All to put a wide tire onto a chassis that really couldnt use it.
I ride a 2006 VRSCR Street Rod , the fastest , most powerful Harley ever built. It has a 180mm tire and I use almost all of it as an aggressive rider .Really aggressive.
Sport bikes only have 200mm tires cuz' thats all you need.
I would not have bought this chopper if it was left offset silliness.

Back to the problems at hand.
The pic above shows the 1/2" rod used to lie up the sprockets.
Inside of the rod - outside of the pictured sprocket is approx: .600"
Sprocket is 1.06" off set.
As stated above for some reason the guy put a .25" spacer between the inner primary plate and the engine. Removing this would be .600" minus .25" is: .350" (remaining required offset)
Change the pictured sprocket for PDI's 1.310" offset sprocket would be a gain of .25".
So with the sprocket and removal of the spacer tyhat would give me .5" coming back to the right. I think between .5" - .6 " a diff of .100" can be worked out with spacers or removal of the face of the hub.

I will also check the suppliers mentioned above for an even more offset sprocket if available. ++ I checked. Vulcan has a 1.5" offset sprocket that will help.

The hydraulic clutch can be spaced accordingly but I would cut a one piece spacer if possible.

The math indicates that the lineup of the final drive chain is possible.

[STEINBVG]

Oh there,s no misunderstanding.

I,m really glad you have all figured out.

Keep us posted , preferably with the pictures of your inevitable progress.

Good luck.

[JamesS]

Thanks.
As I said the assy done was not of a finished caliber.
There is no 5th mount for the trans , pretty crucial for this type of drive train.
I'm guessing this was left off until tire size was sorted , regarding the final placement of the trans. The frame has been prematurely painted and there are a number of other mounts to be fabbed and attached , I was hoping to save the paint but there are too many missing mounts.
Where the large bolt in the center of the pic there should be a mount to the frame.: