How to True a Wheel Part 1: How a Wheel Works

hello welcome to part one of our wheel chewing series in this video we're going to look at how the component parts work together when they ride and when we true a wheel wheel chewing is making the corrections to the spinning straightness of the wheel by using spoke tension learn much more about this at our wheelchewing playlist you'll see things about lateral or side to side correction and radial correction all at our wheel chewing playlist [Music] at a fundamental level the wheels act as bearings between the bike and the ground allowing you to roll down the trail or the road but inside the structure of the wheel there's a lot going on bicycle wheels rely on opposing tension from the spokes to suspend the rim around the hub wheel chewing is the process of correcting spoke tension or tightness to correct the spinning straightness of the wheel [Music] let's have a look at the parts of the wheel and how they all fit together as a complete unit we call this the wheel on the outside the rubber part that gives us traction is the tire inside the tire might be an inner tube which acts as a bladder to hold the air pressure or you might have a tubeless system that maintains air pressure without an inner tube next we come to the rim which is basically a hoop inside the rim is commonly a rim strip which protects the inner tube from holes and the spokes in the rim tubeless tire systems commonly use special tapes to seal the inside air tight now we come to the spokes which are basically long skinny fasteners spokes typically attach to the rim using nipples which are the nuts of this fastener system the other end of the spoke attaches to the hub at the center of the wheel the hub contains a bearing system that allows the wheel to rotate the wheel is then attached to the frame or fork and off we go start over for a more detailed look at these component parts while we normally don't consider the tire while chewing the wheel the tire is where the rubber meets the road and so it is important for the wheels performance if the wheel is improperly seated or is damaged to the casing it can look as if the wheel has spoke truing problems this is one reason why it's useful to have the tire removed when you are just learning to true wheels rims that are made of steel or aluminum begin as a straight channel that is cut to length and rolled into a hoop the hoop is then joined by pins at the seam or is welded carbon fiber rims are made in a mold the rim and hub each have matching number of holes for spokes this hub has 16 holes on each side and this room has 32 spoke holes rims are somewhat flexible and actually flatten slightly on the bottom as you ride that means the spokes at the bottom will slightly slacken as they pass to this lowest point and then gain tension again however the biggest concern for the rim is not this normal stress of flexing but the damage a rim might take from impacting things or crashing bicycle spokes can be made of steel titanium aluminum carbon fiber or threads of synthetic fibers the most common spoke is steel which may be either stainless steel or carbon steel both carbon steel and stainless spokes will be magnetic carbon steel spokes are strongly attracted to a magnet however stainless steel is weakly attracted to a strong magnet spokes will come in different lengths to fit various rim and hub dimensions spokes are also available in different finishes spokes are made in different diameters as well as shapes this common spoke is two millimeters in diameter its entire length however a butted spoke will vary in thickness this one is two millimeters at the end but is 1.7 millimeters in the middle a bladed or arrow spoke is shaped to give an elliptical or blade-like appearance the unthreaded end of the spoke traditionally features a j-style bend the j-band has this head that is held at the hub flange an alternative to the j-band is the straight pole spoke there is no bend at the end of the spoke rather it simply ends in a head much like a nail hub flanges must be specially designed for the straight pull spokes the spokes form a pattern as they connect the hub to the rim we call this a cross pattern or a lacing pattern we count the crosses of one spoke as it travels from the flange to the rim beginning here at the hemp flange this boat crosses another spoke here then here for the second cross and finally here at the last crossing before reaching the nipple we call this common lacing pattern a three cross however this wheel is an example of a one cross crossing only once on this side but on this side it does not cross at all and is called radial for purposes of truing the cross pattern doesn't matter the nipple is the nut of the spoke system and is used to change the pulling force or tension in the spark these are commonly attached to the rim however there are exceptions these nipples attach at the hub although less common nipples can be made of steel or can also be made of aluminum to save a little weight and add some color however the common bicycle wheel nipple is made of chrome plated brass the most common nipple design has four wrench flats and is turned by using a spoke wrench when determining what wrench to use is best to use a caliper to determine the width of the flat using a spoke wrench that is too large will round the corners of the nipple so it is important to use the smallest wrench size that fits over the nipple there are also specially shaped nipples which require special wrenches rims can also be manufactured with nipples hidden inside the rim requiring a special wrench to reach them quick grind selection is an important part of wheel chewing see our article on spoke wrench selection here hubs act as the center of rotation for the wheel hubs are commonly made of aluminum and are designed in many different widths the outer body will have flanges on the left and right side to hold the spokes rear hubs are designed with a mechanism for attaching sprockets hubs may also be designed for a rotor disc if the bike uses disc brakes a bearing system in the hub allows the outer shell to rotate around the axle hubs attach to the frame or fork three common methods are a threaded axle with nuts on either side a hollow axle designed for a skewer and a cam mechanism that applies pressure to hold the wheel in place a thru axle system where a connection pin is inserted through closed dropouts and the hub and threads into the frame or fork wheel chewing is the process of using a spoke wrench to change the spoke tension to improve the run out or spinning straightness of a wheel as the nipple is tightened it pulls on the spoke because the material is somewhat elastic it pulls on the hub and the rim creating tension when all the spokes are properly tight they create a pattern of opposing forces that suspend the rim around the hub for example in this section of rim these spokes are pulling the rim to the left and are opposed to these spokes pulling the rim to the right the wheel will become strong and spin straight if all the spokes are correctly tightened there are four basic aspects to good wheel chewing one is the lateral or side to side wheel trying two is the radial or up or down drawing three is the centering or dish and four is the overall tension all of these are covered in our wheel playlist lateral truing is the side-to-side correction of wobbles or lateral deviations as the wheel spins when drawing wheels generally begin by first correcting the lateral or side to side aspect first if we watch here at the chewing stand indicated we can see this slight side to side motion this wheel we would say has adequate lateral turing but this ramp has quite a bit of lateral air with a lot of lateral air the tire can even rub against the frame adjusting the tension of specific spokes can move sections of the rim to help correct lateral errors however there are limits to what changes in spoke tension can accomplish if the rim metal has been bent in a crash or by impact it may not be possible to get it adequately straight the wheel roundness or its amount of up and down movement as it spins is its radial trueness radial truing is adjusting spoke tensions to correct issues of roundness again if the metal of the wheel was bent by impact the results may be limited the two wheels of the bike should be aligned to one another as well as to the center plane of the bike we can see this wheel is off center in the frame the dish or the centering of the wheel can be corrected by adjustments to spoke tension much like any other fasteners spokes have a range of acceptable tightness or tension wheels with extremely varied spoke tension will not stay true or spin straight for very long additionally wheels with spokes that are too tight or too loose can cause problems and that is the basic overview of how all the component parts fit together on your wheel on your bike and in your wheel truing see more on our wheel chewing to dive into wheelchairing give yourself the gift of patience be steady you'll learn a lot and have fun you

Channel: Park Tool

Views: 478,271

Keywords: Bikes, Bike Maintenance, Bike Repair, Bicycles, Bicycle Maintenance, Bicycle Repair, Bike Tools, Bicycle Tools, wheel truing, how to true a wheel, how to wheel true, wheel tension, straighten wheel, how to straighten a wheel, how a wheel works, hubs, spokes, tension

Id: MFOng1UXn-g

Length: 10min 36sec (636 seconds)

Published: Tue Apr 06 2021