Basic Wheel Truing
Wheel truing is one of those mysterious bicycle repairs that scares and confuses many riders. The concept of wheel truing is fairly simple, but it does take practice to get the feel for it, and if you do it wrong, you could end up with an even bigger mess or a broken wheel.
But, if you follow some simple guidelines, and practice on a few old wheels, you’ll be truing your own wheels in no time.
Note: this is not a complete tutorial to wheel truing, but rather, some general guidelines to follow.
You will need:
- Truing stand
- Spoke wrench
To make wheel truing easier, remove the wheel from the bike, and remove the tire and tube from the wheel. You can do minor truing with the tire still on the rim, but make sure it’s deflated. (Otherwise you could puncture the tube.)
You should also drip some penetrating oil, such as Phil Tenacious oil, into each spoke nipple to lubricate the spoke threads.
It will help to have the wheel in a truing stand. Truing stands range in price from $60-220.
A truing stand will hold the wheel steady, and it has easy-to-use indicators that show you exactly where the wheel is out of true. If you plan to true many wheels, I highly recommend you get a truing stand.
However, for minor truing, you make make your own stand by leaving the wheel on your bicycle and attaching some cable ties to the frame or fork legs to serve as trueness indicators.
Laterally true and vertically round
When truing wheels, there are two things to look at: lateral trueness and roundness of the wheel.
Lateral trueness involves side-to-side wobbles (like when the rim rubs the brake pads,) and roundness is how round the wheel is (and involves hops and dips in the rim.)
Left and right spokes.
Spokes are commonly referred to as “left” and “right” spokes.
Left spokes are spokes that are attached to the left hub flange. Right spokes are spokes that are attached to the right hub flange.
Tightening and loosening spokes.
Wheel truing is accomplished by tightening and loosening spokes with a tool called the spoke wrench. The spoke wrench grasps the spoke nipples by the wrench flats so you can turn it.
The confusing part here is which way to turn the nipple. When using a spoke wrench, turning the nipple counter-clockwise tightens the spoke, and turning clockwise loosens the spoke.
This is because you are actually looking at the nipples upside-down. See, when a wheel builder originally installs and tightens nipples, he drops them in from the rim bed (see beneath the rim strip) and tightens them using a special screwdriver called a nipple driver.
During that initial installation, he turns the nipple driver clockwise to tighten the nipples. Once you look at the wheel, you’ll realize that turning a nipple driver clockwise is just like turning a spoke wrench counter-clockwise.
When you are tightening and loosening spokes, work gradually. You will usually turn spokes about 1/2 a turn at a time. Sometimes they will require a full turn, and sometimes just 1/4 or 1/8 turn will do the trick.
If you move too fast, you will probably make the wheel worse than it was before you started!
How to true a wheel laterally.
To true a wheel laterally, you will tighten spokes on one side of the rim and loosen spokes on the other.
Let’s say the rim hits the right brake pad at a certain spot. This means the rim needs pulled back to the left slightly to be true.
You will want to loosen two or three of the right spokes where the rim hits the brake pad, and equally tighten the corresponding left spokes.
How to true vertically (for roundness.)
Sometimes the wheel goes out of round, usually from hitting a big pot hole. You can see this in a truing stand if you find high and low spots on the wheel. (This is hard to do on the bike and usually requires a dedicated truing stand.)
Let’s say you find a high spot, or hop. You will want to tighten the spokes in this spot to pull the rim back toward the hub. So you should tighten the left and right spokes that are right there.
If you find a low spot (or dip,) you want to loosen the spokes right there. Again, loosen a left and a right spoke equally.
Like I said, grab an old wheel and practice. Once you know the basic concepts, practice is the only way to improve.
Caution: It’s possible to snap a spoke while truing a wheel. You should always wear safety glasses while truing wheels!