Bike Rims

Assembly of a wheel starts with the big three: hub, spokes, and the rim. You will need a spoke wrench, truing stand, a flathead screwdriver, and a lot of patience. Wheelbuilding is an art.

This is the Rim page. For hub selection, go to the hub! The type of wheel you are building will influence the hub size, number of spoke holes, and flange girth.

On average, wheels have 32 spokes. There's variation, but keep in mind that with fewer spokes requires a bulkier rim and hub to handle the tension spread out farther. Nickel-plated brass spoke nipples are commonly purchased with the set of spokes.

Let's get started: It's a great idea to lubricate spoke threads, holes and nipples during assembly. Having grease on these spots allow the nipples to reach high tensions (super important). After that preparation, it's time to start lacing the spokes.

NOTE: This is just one of many ways to lace spokes.

Spokes are laced in groups. The first place to start is aptly named the key spoke. If a mistake is made on the first spoke, the others will all be assembled in correctly. It goes next to the valve hole on the rim and through the hub flange, inside to outside. Spokes are set trailing the freewheel around the circle. Along the rim, spoke holes are drilled offset to each other every other hole. They are a little forward from the corresponding hub flange to accommodate the trailing style that spokes are laced. Looking at the wheel from the drive side, the spokes should go clockwise.

Loosely attach spoke nipples to hold the spokes in place. Don't tighten until al the spokes are in the rim and ready to rock. On a 32-spoke wheel, the spokes are installed in groups of 9. They should be evenly spaced, and wired to the same side on the rim as the corresponding hub flange. When the first group is in place there should be a spoke, 3 empty holes, another spoke. 

Next comes the 2nd group. It should follow the holes behind the 9 first spokes in the same flow. The first spoke of the second group goes into the first hole opposite the key spoke. After this group there will be 18 spokes in the wheel, all up to this point have been trailing spokes.

The third and final group is a leading group. The spokes will insert the opposite direction and cross 3 of the trailing spokes before finding their home. Remember to keep the spokes in holes on the same side of both the rim and the hub. Install the remaining spokes this way to complete what is called a normal cross 3 pattern. Now the spokes will need to be tensioned properly.

If you are still unsure, check out the great bike tube tutorial on how to build a wheel. It really breaks it down and there's a lot of humor to keep you awake.

Repairing bent rims (called truing) can be one of the most difficult tasks to do on a bicycle. If the rim is bent, or it's noticed that it is coming close to touching a brake pad, your wheel probably needs to be trued. Bringing the rim back into balance takes attention to detail that's mostly learned from building wheels in the first place. Patience is key, so if you're ready to bring that wheel back from the dead, here are some tips:

• Get a truing stand - the wheel can sometimes be trued while the bike is flipped over, but it just simplifies working on the wheel. Truing stands help notice slight imperfections that would otherwise be overlooked still in the frame dropouts.

Take a deep breath and don't rush anything. If there is a small flaw in the rim, you can find it by shining a light on the rim. In the reflection you will be able to find where the smooth stops and the trouble starts. Before messing with any spokes, try to hit the rim lightly with a rubber hammer to flatten the bump. Remember that you are working with very light metals, and overcorrecting can give more headaches than you might be ready for. Be gentle.

When corrections are made to a small part of the rim, it affects the geometry of the whole thing. Work around the rim making even, small turns of the spoke nipples. Constantly check that spoke tension is even with your fingers. They should bend only under significant pressure. Broken spokes will be apparent.

One thing to consider is that if the rim is severely dented, simply tightening loose spokes will only further deform the rim. Use a hammer to get the rim as close to round as possible before tightening spoke nipples. When a loose spoke is found, sometimes it is helpful to check the adjacent spokes at the same time. Covering more spokes makes a more uniform, round area of the rim. 

And finally: don't be a hero. If you have made many adjustments at very small increments and the wheel just doesn't seem to come into balance, take it to a professional. Solving the problems early and without too many adjustments will keep from further weakening the rim.