Fixing a botched swingarm swap

What is the widest rear tire i can put on the stock '78 (B2) rim (16x3) and not have to move the sprocket in order for the chain to clear the tire?

I bought a '78 KZ1000 B2 that came with a botched GS swingarm swap that I need to fix. I know from reading several discussions here that I have several steps to go through before I get everything right but I thought I would start with this one question because it could help me understand my options in dealing with the rear tire width and simplify one part of the equation.

Here is what I am starting with:
GS1100 Swingarm that looks like it is from the early 80's. It is aluminum.
The GS axle. All of the KZ spacers plus a couple of washers.
A KZ mag 16x3 rim.
The wrong sprocket carrier - I think it is from a later model that is not as wide as the B2's
A sprocket that has had a smaller sprocket welded to it as a spacer
The rear and front sprockets are not aligned. The rear needs to be pushed outboard about the thickness of the rear sprocket plus 1/16th of an inch.
A 150 rear tire
A 630 chain
The chain rubs the tire
An aluminum caliper bracket made out of a single flat piece of plat aluminum.
A Performance Machine caliper
The caliper and bracket were not mounted perfectly and so rubs the disc with a noticeable drag when pushing the bike.

Thanks

Pictures would help. What are you trying to do? Restore to original or just get it running right?
In theory you could put anysize tyre on it,shove the whole lot over to the right and have it line up with the sprocket. Some people have no problem with running an off center wheel Apparently Harley does it (not a great recommendation) Some Japanese cruisers do it and what surprised me was that Kawasaki do it with the ZRX.
The GS swingarm is a common swap and you should be able to sort it. I think someone said to me that 140 is the biggest tyre you can get in it.
Other than that you could source an original swingarm ,sprocket carrier and brake caliper mount and put it back to the way it was. With and original size tyre. I think the 630 chain is OK. Again pictures would help.

like davido said pic's would help.
shooting from the hip,tho how about spacing the rear sprocket out to align the chain???
i believe a 150 will fit and function in that arm,although too wide for the wheel.

hth,
leon

On my '73 Z1-900, I use a 166 mm wide Avon radial rear tire on an Excel 4.25" wide aluminum rim, but I needed to use a 1/4" offset countershaft sprocket and I also had to offset the rear sprocket in the rear hub to match. It was works wonderfully.

just trying to get it running right with the GS swing-arm and PM brake.

I was planning my first move to be getting a stock carrier and sprocket and see if I can get the chain to clear the 150mm tire. I would downsize the tire if necessary to avoid offsetting sprockets or moving the tire over to the right. If what you heard is correct, I'll need to go down to at least 140mm. This might be best anyway if a 150 is too wide for safety like I have heard and davico might be implying - I have also heard this is fine, however.

Here are more pics

Nice, BohicaBob. What swingarm are you using?

One specific question I have is, by how much is the swingarm supposed to "squeeze" together when I tighten the castle nut on the axle? This will help me get the spacers correct on the outside of the caliper bracket and on the out side of the hub on the left. E.g., Do the ends of the swingarm squeeze together enough to get the shocks straight up and down? Or, are we talking something like no more than half and inch?

Thanks

The swing arm should not "squeeze together" at all as far as the eye can tell. The spacers, etc. should take up all the space between the two arms with no noticeable slack, and tightening the axle nut should simply lock the axle and adjusters in place so they do not move. If you need the arms to squeeze in more than 1/16" something is wrong and should be corrected. Ed

ed is correct.
everything(spacers,inner bearing races,inner bushing,adjusters)should all stack on the axle with no gaps. to create a slip fit into the axle plates
you can space out the upper shock mounts to get em straightened out.


hth,

leon

thanks ed and leon. that helped alot.

Back on the road again. Thanks for the help!