To check if you wheel is out of true, or out of alignment, you can use the following test. Turn the bike upside down to rest on the seat and handlebars and spin the wheels. Look and see if there is a wobble or if the wheel rubs or touches the brake pad at any point while it is spinning. Sometimes you can hold your finger adjacent to the brake pad and feel for areas of contact of the rim on your finger while the wheel is spinning. If you are riding and have a wipeout, or bash the wheel on a big rock, or drop your bike, this may cause a noticeable wobble when you get back on as you may have bent the rim and taken the wheel out of true. Sometimes you are made aware of the wheel being out of true because it may rub on the brakepad. It is a good idea to always lift up your bike before a ride and spin each wheel to see if it spins freely and does not rub against the brake pad. If it does, and your pads are in the proper position, your wheel may need truing. Another test we do is the tone test. Take a small screwdriver and let it hit the spokes while spinning the wheel with the bike upside down. Each spoke should ring out melodically and not sound like a “thud” or “dull” sound. If one does, it may be a dead spoke and have no tension on it and require tightening. You can also grip each spoke individually and see if it wiggles or feels loose. These dead spokes should be tightened first and put under tension using the spoke wrench. The best way to true a wheel is to take the wheel off of the bike, remove the tire, tube, rim tape and use a truing stand. This is best done in a bike shop but is generally not needed for mountainbike riding and is often not feasible. Instead, The Wrecking Crew has come up with a technique which will work in the field. You only need one tool > the appropriate size spoke wrench. There are generally three sizes to chose from that fit the spoke properly. You need the right size for your bike! I carry all three sizes when I ride so I can true any wheel on the trail or before a ride. It is usually a good idea to check your wheels for trueness after every couple of rides, especially if the wheel is new or the terrain is nasty. Always have the right size spoke wrench for your bike. If you have the spoke wrench, there is one more important thing to know>>which way tightens the spoke! If you want to tighten a spoke, you turn the wrench COUNTERCLOCKWISE against the rim as you look from the hub to the rim. Unless you do this all the time, believe me, you will make a mistake a couple of times and not turn the correct way. Do a test on one spoke and turn it a couple of turns to see the effect so you know how to tighten or loosen it. Here is what you do: Turn the bike upside down. Spin the wheel you are truing. If it wobbles, place your finger on the brake pad next to the rim so that you lighly touch the rim at every point except the area of the wobble. You will see that the rim is off to one side at a certain location. Next, remember that the spokes come out from both sides of the hub. Some come from the right side and some from the left. Naturally, tightening a spoke from the right side of the hub pulls the wheel to the right. Note that the spokes alternate right >left>right>left>etc... Tightening a spoke from the left side of the hub pulls the wheel to the left. O.K. If your wheel is warped out to the right, then you need to tighten the spoke connecting to the left side of the hub. Start with a slight adjustment - about a half a turn for the spoke at the wobble center, one quarter turn for the spokes on either side, one eight a turn for the next two spokes. These spoke are not next to one another because remember they alternate. You can also do the opposite and loosen spokes to affect the wobble, as sometimes you might have to loosen some spokes and tighten others in the wobble area to produce a true wheel. When you finger test and vision tells you all looks even, and the wheel seems to spin true, you are almost done. There are two more things>>>> Check the spokes for approximately the same tension by squeezing with your fingers two at a time, by wiggling, or the tone test. Then make sure that the wheel is reasonably centered between the forks (front wheel) or chainstays (rear wheel) and you didn’t move the wheel too far to one side. |
