what is the best way to be sure the rear wheel on Ironhead is align after rear wheel removal?

 

I use a razor blade and count the number of threads protruding from the rear axel adjusters on each side, ensuring that they are the same. This is the technique in the factory service manual.

 

also straight edge from rear tire to front tire--ck. both sides

 

+1

hold it up as close to the axles as you can get so it touches the inside and outside of both the front and rear wheel. Make sure it touches all 4 points and from both sides. Also check your chain for tension; at least 1/2" of play at the tightest point in the chain.

 

Local indie uses a 6' or 8' fluorescent tube.

 

You must be kidding.
What if......
They have become mismatched at some point in the history of the vehicle.
One is bent.
An idiot former owner cut one off for whatever ridiculous reason.
You simply have different nuts on them.

Mick, mick, mick.
Centre of swingarm to centre of axle is the only reliable way.

 

In no way does that square the rear wheel.
The wheel must already be square to even think about beginning that part.

 

Wow.
Just like NASA builds a rocket.

 

[Not bent, not cut off, same nuts, and you cannot access the left end of the swingarm pivot bolt for accurate measurement.

Measuring by the rear axel adjusters is the method given in the factory service manual, and it is the usual method that has been used for decades.

 

'Mick, mick, mick.
Centre of swingarm to centre of axle is the only reliable way.'

the assumption has been made that the wheel has been returned to the bike the same as it came off with all spacers in the original places so the wheel is centered on the axle.

Fluorescent tubes are a reliable yet inexpensive straight edge that would allow you to easily see and make the required adjustments.

The goal is to have the straight edge touching the front and back edge of both front and rear wheels at the same time and make adjustments to the back wheel until this is achieved.

'Wow.
Just like NASA builds a rocket.'

call it rocket science if you want...it's really just simple reliable DIY backyard mechanics under a budget for those that need it.