Originally Posted by
LinuxLefty
How do I know if a rim is bent or is just not staying true?
If it can be made true with roughly uniform tension in a side except at the rim joint it's not bent.
Without obvious damage when it's true and tension is uneven within a side you can't know whether it's a bad build + true or compensation for a bend until you try to correct it.
You have reasonable latitude to move tension to adjacent spokes except at the rim joint which can be stiffer than elsewhere due to a joining ferule, especially in conventional (32ish) spoke count wheels without too much unsupported distance between spokes.
Loose non-drive-side spokes are the problem because they don't have enough tension to keep the nipples parked when they pass the bottom of the wheel and slacken farther from your weight. Loose drive-side spokes are also a problem because the opposite non-drive-side spokes may be loose to make the wheel true laterally.
See what's going on around loose spokes. If one loose spoke is between two tight ones in the same side you could tighten it twice as much as you loosen its neighbors. If it's in an otherwise uniform area you want to spread the changes around more - you might tighten it a turn and a half, loosen its immediate neighbors on the side a half turn, and loosen the spokes next to them a quarter turn.
If you can't get the non-drive-side rear spokes next to the ferrule tight enough with the wheel staying true you want to compromise with a low spot and higher tension - you won't feel a small dip.
Some cities have bicycle cooperatives which give people a place to work on their bikes. With one nearby you might see if there's some one who can show you the ropes with wheel truing.
As a 'clide, do I need to be ultra-vigilant about making sure the wheel remains true and in even tension?
No, you just need rims built for people bigger than the average 140-160 pound bicycle racer (400 gram box section rims are right out) which won't bend under your weight plus proper uniform tension.
Once you do that your wheels will stay true until you bend the rims (which will be unlikely when they're appropriately selected) or wear out the brake tracks and need to replace them.
If you're mechanically inclined I strongly suggest learning to deal with your own wheels because while time consuming it's not hard - although it can be a three beer project building a wheel from scratch is only as technically challenging as adjusting a front derailleur.
If not find a reputable one-person operation which may require shipping across state lines.
Locally wheel building goes for $70; although bike shops can charge $80 to replace cables. Obviously they make more money when they have their mechanics spend their time on faster services they can charge more money for.
At the low end people get inexpensive wheels from QBP ($25 can net a whole wheel) and most of the rest opt for boutique wheels so there isn't enough demand and resulting practice for the average bike shop mechanic to get speedy building quality wheels.
The usual compromise is fast wheel builds with low quality.