Did the search... nothing really specifically relating to this item showed.

I did mount a 7 sp freewheel when I had my rear rim re-spoked. Works fine.. one can see the chain angle is
too sharp onto the outer 2 cogs... especially with the inner 40 being used. I wore the original BB out
back when.. had a good sealed bearing unit put in for a replacement.

Spindle width I assume is the issue.... this Schwinn Traveller is an '84... have no idea what width the
spindle/stem is now. How do I figure the width needed for this 7 on back? I'm at 130 mm width I believe
now for the rear.

I assume... you'd center the 4th cog in the freewheel.. the chainline straight back from the inside crank? Or.. how to figure this added width needed?

Had considered going to the triple.. but with the 14-34 on the rear.. 52/40 front.. wide range that works
for me. Which brings the next issue up: I'll need a new rear derailer to utilize the 34 cog... figure
going a index shifting rapid fire type.. which one/unit is well made, cost efficent and works well/durable?

Thanks!

I'd measure the current drive side spindle length and get one that 2-3 millimeters longer.

shimano deore is inexpensive. my last one lasted me 5 years of hard riding and little maintenance.

Ideally the middle rear cog should line up with the space between your two front chainrings. A millimeter or so one way or the other shouldn't matter.

I would think the spacing is 126 not 130. Also, no chainline expert am I, but the center point of your 7 speed freewheel is gonna line up pretty much the same as the original freewheel. I am kind of surprised the 7 speed wheel makes such a noticable difference. I would first check dish of the wheel; if your current chainline is centered toward the larger cogs rather than in the center of the freewheel, could be that moving some axle spacers around might be in order.

As to spindle length. I've had three different very good bike shops swap out bottom brackets on three older bikes because I can never get the fixed cups out. In each case, they used a spindle length that was too short, because very few mechanics, especially those under the age of 40, know that older spindles were not always symmetrical. The drive side was longer. Too compensate, you need a new symmetrical spindle that is usually 3-5 mm longer.

In a couple instances the bike shops insisted they had used the longest length available. It was never true. They used the longest they had at that moment.

Sheldon Brown has a great page that tells you how to figure out what spindle length you need. Ideally, your center chainring or the center of your two chainrings should line up with the center cog of your freewheel. But being off by a mm or 2 isn't a huge deal.