Once your wheel is laced, the next step is to tension it. It’s important to take this in small steps, increasing the tension gradually and evenly, while constantly checking that the wheel remains round. The most common mistake is to crank up the tension too fast, without straightening the rim between each round of spoke tightening.
Follow steps 1–6 below for a wheel that is fairly round, true and dished. Then start again at the valve hole, and go methodically around, tightening each spoke a quarter-turn. Repeat steps 3 to 6, truing the wheel more precisely. Go round again, tightening each spoke a further turn. Refer to a set of working wheels, so that you can compare spoke tension. Keep tightening all spokes, then correcting true, dish and hop. Once you get close to the tension in the working wheels, stress-relieve the spokes.
Step 1: If you’ve just built your wheel, most spokes will be loose. Give all spokes an even amount of tension. Tighten each nipple until the spoke thread just disappears. Set wheel in the jig and spin. Pluck the spokes with a fingernail. To start the truing process, most need to be tight enough to get a note from. If most do, skip to next step. Otherwise, start at the valve hole and tighten each one a quarter-turn. Repeat until the wheel has some tension.
Step 2: Once you have a degree of tension in the wheel, you can start truing it. Spin the wheel again. It probably doesn’t look round at all. Your jig has an adjustable indicator – set this so that when you spin the wheel, the indicator only touches the side of the rim in one place. This is the most out-of-true section.
Step 3: Find the centre of this biggest bulge. Loosen the spoke at the outside of the bend a half-turn, and tighten the spokes on either side a quarter-turn. This won’t make much difference, but that’s okay. This step has potential for going horribly wrong, so we’ll take it in very small stages to maximize our chances of success.
Step 4: Repeat the procedure. Spin the wheel, identify the worst bulge, loosen the spoke at the centre, tighten those at both sides, until the wheel moves from side to side no more than 10mm (3/8 inch). This can mean working repeatedly on the same area; don’t worry as long as you are always attacking the biggest bulge.
Step 5: Once you have the wheel vaguely true, spin it and check for hops. Move hop indicator on your wheel jig as close as it will go; watch the gap vary as wheel turns. It’s easier to draw rim nearer to the hub than force it away, so concentrate on areas where rim hops outward. As with truing the wheel, work on the largest hop. When you find it, tighten the two spokes at its centre a half-turn. Repeat until the total hop in the rim is less than 3mm (3/16 inch).
Step 6: Check the dish is correct; if you’re unsure how dish works. Turn the wheel over in the jig or in the bike without moving the indicators. If the wheel is perfectly dished, the rim sits in the same place again. If it’s off to one side, it moves over in the jig. Correct by tightening all the spokes on the outer side one quarter-turn. If this is not enough, loosen all the opposite spokes a quarter-turn. Repeat until the wheel sits centrally.
Source : BIKE MAINTENANCE TIPS, TRICKS & TECHNIQUES
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