Hope this helps. Improve this answer. Mark Mark 26 1 1 bronze badge. The standard for what "true" means varies by mechanic and the intended use of the wheel.
However it requires 4 things: Perfect roundness, measured by placing a gauge under the edge of the rim, and spinning the wheel. Perfect lateral runout, or rather a lack of runout. This is measured by placing a gauge at the brake track of the wheel, and rotating the wheel to track the runout.
Perfect Dish. Dish refers to the centering of the rim on the axle, or in some cases between the dropouts of the frame. This is measured using a truing stand or a dishing tool. Perfectly even and balanced spoke tension. Measure using a tensiometer, the value here will vary significantly based on the type of spoke, the size of the rim, the material of the spoke nipple. But the constant here is that all the spokes should have exactly equal tension. The additional to all that is that even if you had a mechanically perfect wheel, you still need to add a tyre and maybe tube to the setup.
They aren't nearly as adjustable as a wheel. A great summary. Any standards or rules of thumb on an acceptable amount of out-of-round, lateral runout and dish? I am looking at the front wheel I just built and wondering if there is much worth trying to do better than 0. This is coming from a hobbyist perspective.
What runout is acceptable depends on the use of the wheel, and the manufacturer. Xentis uses. July 11, at pm. E-z E says:. July 12, at pm. Danny Reyes says:. July 16, at am. July 16, at pm. Mike says:. August 13, at pm. Destin says:. August 19, at pm. August 20, at am. September 5, at am. September 7, at am. Fred says:. September 10, at pm.
September 11, at am. Diego says:. November 11, at am. Paul says:. December 9, at am. December 9, at pm. April 23, at pm. April 27, at pm. Skip says:. July 15, at pm. July 17, at am. Ellis McCarty says:. August 5, at pm. Dalton says:. October 10, at am. October 12, at pm. October 13, at am. Leave a Reply Cancel reply Your email address will not be published. Because the rim is somewhat flexible, we tend to correct both high and low spots to average out the rim for adequate roundness.
For radial truing, it does not matter if you are paying attention to the left or right edge of the rim sidewall. In fact, for beginners we recommend using one indicator at a time as with lateral truing. Spin the wheel and adjust your indicator so it is sitting below the outer edge of the rim, but not close to touching the rim. Sight along the gap between your indicator and the rim to get a sense of the radial deviations. Slowly move the indicator towards the rim, watching for where the rim gets close to the indicator.
Begin by locating a high spot — slowly move the caliper arm upward until you see or hear it lightly contact the spinning rim. Back the indicator away if necessary until you are sure it is a light rub at the highest spot. Isolate this high spot by slowly moving the rim back and forth though this area to see where it begins and ends.
Correct this radial deviation by moving this section of rim toward the hub. To do this, we are going to tighten an even number of spokes from both flanges. This is because the spokes not only pull the rim left to right, they also pull the rim toward the hub.
A way to simulate and visualize what tightening does is to squeeze both a left and right side spoke at the same time.
For now, give each of the spokes associated with the high spot area a half-turn. Spin the wheel to verify that the high spot was reduced and the rim is no longer rubbing. As you correct radial deviations, tighten spokes evenly in pairs of two to avoid introducing lateral deviations. It is, however, inevitable that you will create some new lateral deviations. Every 3 or 4 radial corrections, check that lateral true is still acceptable and adjust as necessary.
Typically it is best to begin radial truing by addressing high spots. After reducing these, the low spots may not look so low. Spin the rim and locate the areas where gap between rim and indicator is the largest. Move the rim back and forth in this zone and isolate the spokes that should be adjusted to correct this deviation, just like you did for the high spots.
This time, though, loosen the sets of spokes instead of tightening them. Move the rim back and forth through the low area to see if the radial deviation has gotten smaller. It may take a few attempts to see progress. Continue the process of locating, isolating, and correcting, and again, check again for lateral errors after every few radial corrections. Most significantly: the wheel will have a tire on it, and tires are not often made to such tight tolerances.
As a general guideline, 1 millimeter or less of radial deviation is an acceptable measurement. Use this as a feeler gauge to help you visualize what 1mm looks like.
If it gives you satisfaction to continue and make the wheel spin rounder and rounder, then continue with locating, isolating and correcting yet smaller and smaller deviations.
Destressing a wheel allows spokes that were wound up from turning the nipple to unwind. There are a few different ways to do this, but the safest is to simply install it in the bike and take it out for a ride. Expect to hear some pinging and popping for the first few pedal strokes. That is common and not a concern. Not every wheel can be made sufficiently true. Sometimes damage to components of the wheel can prevent a wheel from being made reliably true:.
Rims may become damaged from impacts, such as hitting a rock, pothole or curb. Impacts to the side of the rim from falling down or crashing can also cause damage. It may be possible, in some cases, to repair the wheel with adjustments to spoke tension.
The chain…. Knowing how to straighten a bent bike rim allows me to effortlessly speed up any driveways with my fixed rim. To straighten bike rim, start by carefully turning to the rim area where it hits brake pad, tighten the spoke opposite to the damaged area.
Then, Tighten the bike spokes. After fixing the wheel and making the gaps even, proceed with pressing each pair of spokes in your bike rim. Knowing how to straighten a bent bike rim allows you to effortlessly speed up any driveways with your fixed rim. You can also ditch the worry of having a bent rim that slows you down.
My son told me that the bicycle I gave to him last week is producing a rattling and weird sound. I will make sure to consider all your tips. Hi there! Am I looking at replacing the rim or is it still possible to true it? I am going to have my bike service next week but if the rim is irreparable then I can buy a new one before the service date so that they can build it up and put it on my bike.
Waiting for a reply. Hi David, it depends on how big the wobble is. Best to bring it in to the shop to let a mechanic assess, but rims are often salvageable.
How untrue is seriously untrue? Please respond asap, Thanks -Trent t. Your email address will not be published. Save my name, email, and website in this browser for the next time I comment.
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