I am doing a budget commuter rebuild on a Panasonic DX-2000, which is coming out great (brush painted with rustoleum and it looks fantastic!), but I am rebuilding the old Arya 27" wheels/Shimano high flange hubs (no model name/#) and having a bear of a time with spoke lengths.

The problem (pre-disassembly) was that the rear wheel was impossible to true. As close to true as I could get it (which was still unrideable) half the spokes were under very low tension and half were very high...so I took everything apart and determined that I would rebuild it with different spoke lengths for the rear, and just go ahead and do the front with it using the same spoke lengths.

Spoke length calculators are confusing the heck out of me, and it doesn't help that I don't have a computer at home for quick reference. I gave up on them, and instead my question is this:

All of the spokes on the rear wheel were the same length (310mm), so would it be reasonable to guesstimate a shorter length for half of the spokes and rebuild it that way? E.g., 310mm for half and ~305mm for the other half?

Sounds like it's time for a new rim. Most 27" box rims have the same ERD. I would measure the ones you have and look at Sun CR18's as a replacement.

Spoke tension and length on back wheels is complicated.

I'm going to send you to the library... use the computer there to look up https://sheldonbrown.com/wheelbuild.html

There have also been some good books written on wheel building.

Wheel building is an art and a science. That is why hand built wheels are better than machine built wheels.
I hope you find the information you need

Did you look at how high the spokes came in the nipples before taking the wheels apart. The ideal length is that which brings the spoke to within 1mm of the top of the nipple. So the difference between where your old spokes ended and that place is your adjustment factor, and your new spokes should be longer or shorter accordingly.

In any case the difference in spoke length between right and left flanges is typically only about 2mm, not 5mm.

most wheels of that size have 3 mm different between the two sizes, like if one is 310 then the other side is 307 or 313 mm . the shorter size would be the driveside.

My buddy went the Sun Rims route and they are complete crap, so much so that I would rather stick with what I have already...budget > garbage.

Thank you for the suggestion, however.

Been there my friend...don't find it too much of a help for me because I don't have a computer at home for quick reference and I'd rather not copy the whole page by hand.

Thank you kindly sirs, that is what I was looking for.

Sun rims are not complete crap. The CR-18 rim that another poster suggested is a common budget replacement.

The rim that you have now is crap. It's warped so badly that it can't be trued and, being 25 years (or so) old, probably has significant brake track wear. There is no way to build a reliable wheel using that rim.

https://www.mrrabbit.net/wheelsbyflemingapplications.php

Grab the spreadsheet a little ways down...

I build 27 x 1 1/4 wheels all the time....one of my best selling wheels.

Patience is the key with 'em...get the drive side up to the 107-110 kgf range dished and stress relieve.

=8-)

That one made me smile. Sorry to have gotten you worked up over Sun Rims; by all means keep their spirit alive and well in the biking industry. Personally, I think they're crap. I'll stick with my horribly warped rim.

Rockin! Thanks man!

may I interject something here? depending where the OP buys his spokes he is going to pay between .75c to $2.00 per spoke. at .75 he is looking at only $54 for spokes, $1.00 ea. $72 and so one.

unless the OP is desperate to have those HF hubs or really wants to build a wheel, and unless the origianl rim was really bent, it sounds like he may have some difficulty in this task.

I suggest the OP simply buy wheels. a pair of decent 27" wheels can be had for about $80 or so. see the Demension wheels in the second row

https://www.niagaracycle.com/index.php?cPath=135_198

Then be prepared to have a lot of problems getting the spokes up to any sort of uniform tension.

way to ignore some of the best advice given in this thread.

That one made me smile.

You must be a really fast learner. A day ago you were asking for advice regarding a relatively routine wheelbuilding question. 26 hours later you've become an expert.

That one really made me smile.

The first time that I read through it I thought that you said "origami" rim.

this thread is getting real interesting.

1. This thread got boring really quick...because I posted. =8-)

2. "Origami" actually sounds like a good name-brand for a line or rims. Only problem is - you have to make sure the marketing and sales on the name is in reference to style, coloring, lacing, etc. Not the physical structure per se.

=8-)

origami brand rims? I think mark Cavendish is using them already

Hmmm...seems to be the popular suggestion but not going to buy new rims. New quality spokes + extras ~$25.

I'm a super fast learner, what can I say? I'm now using the power of my mind to re-arrange the molecular structure of the rim, making it un-warped and carbon fiber at the same time. I can't fabricate spokes though...something about the law of conservation of mass.

Yawn. Blah blah blah.

Somewhat frowned upon, as no one really can put a figure on the integrity losses occurred, and the questionable use of the builder's time - it is still entirely possible to straighten a warped rim sufficiently to make retensioning a far easier task.
I prefer to lay the rim with its high spots over a broom stick (or something) and then step on it, other prefer to clamp it to a work bench and heave down at it to apply leverage.
I'm sure a moderately clever use of the search function would locate a few threads on the subject.