No need to paint rusty spokes when I have a set of clean and shiny spokes that I can use if I can figure out if they are good. Thanks though.
Turns out that the rim is 1/16" out of round. I guess that is the unacceptable tolerance for the shop, but I believe it's accepable according to the manual.
The shop I took it to did say that my bike was too old for them to even touch, so maybe they just wanted me to go away.
Wow! One entire sixteenth of an inch! The horror!
My Honda service manual states that 2mm of axial and 2mm of lateral runout is acceptable (for my 1980 CB750K), which would make that rim completely and utterly...within the manufacturer's tolerance.
Some shops are just scared, methinks, of the Old Ways. Funnily enough, the guys at your local bicycle shop probably know much more about spoked wheels and would be perfectly able to true up your wheel if liability allowed for it.
I'm no wheel expert, but if I were checking a set of spokes I wouldn't bother with straightness. Quality steel can be bent back a few times without harming its strength and spokes are meant to flex a bit in normal operation. I would be more interested in visible damage, corrosion, surface finish, galling or stretching of the nipple threads, and the (much softer) aluminum hub of the wheel.
Corrosion should be checked to make sure there's no pitting. If there is, I'd replace the spoke as there's not a lot of material and any missing chunks compromise the strength. Surface rust that can be easily cleaned off, or powdery white zinc corrosion on the surface, are both fine.
Surface finish because if you're gonna reuse the spoke, you should refinish it to prevent further corrosion. Paint won't do because of the direct contact between the wide end of the spoke and the hub and it won't flex with the spoke. Metal plating is the traditional option. When I rebuilt my rear wheel I had to reuse a spoke despite having a whole new kit because the seller shipped the wrong number of inners and outers; I just buffed up one of the previous spokes on a buffer to clear away the powdery zinc on the surface.
Galling or stretching of the threads is another possible weak spot. If the previous technician or owners weren't careful in using anti-seize or grease on the threads when assembling, and/or overtightened any spokes, then that's also a recipe for a weakened spoke. Replace if you find either as threads do not get better after they've started to yield. You can check for this by holding a straight edge against the peaks of the threads. If any of the threads have an hourglass shape to them, that's trouble.
The spoke holes in the hub are arguably the weakest spot in the whole wheel system because they're not steel. Look carefully to make sure none of them have been "stretched" beyond their correct round shape. You want no ovals. It's caused by incorrect spoke tension and is a significant safety risk. The only easy way to fix it is, unfortunately, replacing the hub.
Theoretically you could try heating the aluminum of the flange and tapping it with a hammer until it's closer to round, then drill and countersink the hole properly again, but that is the Sketchy Way. A machine shop might be the better option for repair if you couldn't find a replacement hub.
Again, I'm not an expert. I'm just good at sounding like one and read a lot before attempting things. I rebuilt a rear wheel just recently so this is all fresh in my head.
