Over time, all spoked wheels will tend to loosen somewhat. The time-honored method of checking a spoked wheel is to give it a tap with a screwdriver or wrench. If the spoked gives off a nice clear ping, it’s still under tension; if the note is flat or dull, it’s loose.
• A spoke wrench
• A good ear
Loose spokes tend to break, and broken spokes are a bad thing, as they tend to flop around and puncture the inner tube. Besides, one broken spoke can lead to five or six or ten broken spokes, and as you might imagine, a wheel with ten broken spokes is a wheel that’s no longer safe.
So if your bike has spoked wheels, you should learn how to check and true these wheels. The first step is to get the wheel you’re checking off the ground. Then, give each spoke a tap and a listen.
Don’t be alarmed if each spoke isn’t tuned to an E sharp because we’re not tuning a piano for the Philharmonic. If the bike has any real miles on it, chances are you’ll find one or more that “thunk” rather than “ping.” Use your spoke wrench to tighten the loose spoke a quarter of a turn and then recheck it. Tighten each loose spoke in turn and then recheck them all.
If they are still loose, give them another quarter turn and recheck until all are snug. Since tightening one spoke can cause another to loosen, it’s easy to start “chasing” loose spokes around the rim if you start trying to tighten them more than a quarter turns at a time.
An alternative method and one that I prefer to use is to start at the tire valve stem. Locate the first spoke after the valve stem and apply your wrench. If the spoke turns with light to moderate effort, move it a quarter turn.
Count to the fourth spoke and repeat. Work your way back to the original spoked wheel plus one and repeat the operation, tightening every fourth spoke a quarter turn. Work your way back to the third spoke and begin again. Keep the cycle going until all the spokes are snug.
It sounds like a lot of work but it should take less than 10 minutes a wheel, and you only need do it once or twice a year.
During the normal course of use spoked rims tend to twist slightly. This is called run-out. Run-out from side to side is called “wobble,” up and down, “hop.” In extreme cases run-out can be very difficult to fix; many wheel builders tell me that rather than true a wheel that’s really bad, they’d just as soon loosen everything up and start fresh. For the average rider that’s not really a great option.
Obviously, if you can see the rim wobble or hop you know you’ve got a problem. How much of a problem is debatable. All manufacturers list acceptable wheel runout specs in their shop manuals.
As a rough rule, about 0.025 of an inch or one millimeter is acceptable, but check your manual for the specifics, some may allow as much as 3mm of run-out. To measure the run-out, mount a stationary pointer on the fork leg or swingarm. Position it so that it just kisses the rim at the closest point.
As you’re checking the run-out, give the wheel a good shake to check the wheel bearings; if the play is obvious, renew the wheel bearings before proceeding. Measure the rim at its closest point and farthest point. If it’s not within spec, you’ll need to adjust the spoke tension.
To cure up-and-down out of round, you’ll need to loosen the spokes on the low side of the wheel and tighten the spokes on the high side to pull the rim into shape. Loosen the spokes only by two or three turns and tighten the opposite side by the same amount. Make certain that you always loosen and tighten an equal amount of spokes on both sides of the rim.
To correct side-to-side run out loosen the spokes on the side of the hub you want to pull away from, and tighten the spokes on the side you want to pull toward. If you end up turning the nipples more than three to five turns to true the wheel, I’d suggest you break down the tire and file down any of the spoke heads protruding from the nipple so they don’t puncture the tire.
As you’d expect, this is tedious work and it’s easy to make one false move and send the whole wheel out of whack. Experienced wheel builders work as much by feel like anything, which is one reason I recommend you avail yourself of their services if you have any real problems.
Read also about wheels building and truing