Building a reliable carbon wheelset is actually an art.For most people, the carbon bike wheel building seems rather complicated. You need to order a dozen suitable spokes, otherwise the yaw will be serious. You don't need to string all the spokes at once, you only need one root to operate.
[Carbon Bike Wheel Building Foundation]
I will not elaborate on how the carbon bike wheel group is made up, otherwise a book will not be finished, but it is basically composed of the following four steps:
1. Assembly: insert the spoke into the ear of the flower drum according to the cross way of the spoke (radioactive, two cross, three cross are the most common cross way)
2. Tightening: Tighten the spoke cap step by step. Generally, the weaver will remember the number of turns of each spoke cap to ensure that the spoke has the same tension.
3. True roundness adjustment: When each spoke is locked, the ring will be pulled toward the center of the flower drum, and the true roundness of the ring can be seen by using the adjusting platform, so that the yaw disappears.
4. Centering: Centering is to ensure that the flower drum is located in the middle of the carbon bike rims, that is, the distance between the two sides of the carbon bicycle rim is the same, adjust the tension of the spokes on both sides to adjust the centring degree of the carbon rim. If both the left and right yaw and the up and down yaw of the carbon rim are perfect, and the centrality is perfect, and the spoke position is correct, plus reasonable tension, the carbon wheelset will be round and straight.
There are no perfect carbon bicycle rims and flower drums, and even expensive carbon wheelsets need fine tuning. The job of a wheel builder is to ensure that the carbon cycling rims are round and straight, and that the tension is the same. This is a repetitive iteration, fine-tuning over and over until it is close to the importance of perfect spoke tension. Most riders will use the true roundness of the carbon bicycle wheels to judge the quality of the carbon bike wheel set. However, the real master of wheel building is more concerned about spoke tension.
When the carbon bike wheel is rolling, the spoke circle is tensioned and relaxed to and fro, then tensioned and relaxed. The spoke must bear these pressures, especially at the head of the spoke. Spokes with excessive tension are more likely to be damaged under pressure. However, nothing can prevent metal fatigue, even if the tension remains the same, the risk of broken spokes is spread to each spoke.
Previous carbon bike wheel builders used to judge the tension of spokes by experience, but now there are a variety of accurate tension tools to measure it. These tools are essential for carbon wheel building.
Electronic digital spoke tensiometer has high accuracy. "It takes more time to balance the spoke tension with the tensiometer, but it ensures the balance of the spoke tension and makes the whole life cycle of the carbon wheel set stable.
Of course, you can't guarantee that the tension of the spoke is 100% the same even if you use the bull press tool, as long as it is within the error range. Generally less than 10 percent.
The left side is the final data graph of the front carbon bike wheel tension, while the right side is the rear carbon bike wheel tension map. The tension is divided into left and right sides, marked with blue and green respectively. The front carbon bicycle wheel tension is basically the same on the left and right sides, and the rear carbon bicycle wheel tension will be quite different.
The tensiometer can also be used to diagnose the problems existing in the carbon wheelset and to provide solutions. For example, the spoke tension in Figure 2 is not only over but also over woven. While paying attention to the left and right and up and down yaw, tighten and relax the spoke at the same time to ensure tension balance and not yaw.
It was found that the spoke tension was too high. Once the spoke tension is readjusted, the yaw is much smaller. Asymmetric spoke tension: a special example
All conventional front carbon bike wheels are symmetrical (without disc brake pedals), with the same length of spokes on both sides and the same ultimate tension on both sides.
On the contrary, the tower base of the rear drum destroys the symmetry of the rear drum, and makes the right drum ear closer to the middle of the drum. This side of the drum ear is closer to the ring, so the spoke on this side will be shorter, because the shorter spoke also leads to greater tension on this side.
Over the years, carbon wheel building technicians have used various methods to deal with the asymmetry of rear carbon bicycle wheels. Such as special flower drum ears, or eccentric rim design, these methods can indeed reduce part of the tension imbalance, but there is no way to eliminate the imbalance.
More tools: The small box on the left is used to place the spoke cap, and the turntable on the left.
The difference in tension between the two sides also leads to higher tension and more difficulty in adjusting the spokes on the driving side. To exert greater torsion, when adjusting the spoke cap, it may lead to the sliding teeth of the spoke cap. At this time, lubricating the spoke cap is very important.
Building Carbon Bike Wheels from Right to Left
Because the tension on the right side is relatively large, first put more circles on the right side of the spoke cap, which is conducive to the spoke to achieve higher tension faster, thus less adjustment on the right side, and because the tension on on the left side is lower, it will be easier to adjust the left side.
There are tens of millions of ways to build carbon wheels, but this method helps me build more robust and balanced carbon bike wheels, understand the tension of the left and right spokes, and help me adjust others'carbon wheels.
Here is Bola has our own tricks to deal with high tension for its carbon bike wheel:
First put all spokes and spoke caps on the carbon bike wheel, then tighten to the cap and eat all the threads. Then I quickly use the spoke wrench to rotate the spoke on the driving side to 78% of my target tension. This step does not need to consider the left and right yaw first. The whole process is quite fast.
Then the spoke tensiometer is used to ensure that the tension of all driving sides is the same. When the tension of the driving side meets my requirements, adjust the spoke tension of the driving side to adjust the up and down beating. Check the spoke tension to ensure that the tension between the spoke and the surrounding spoke is fairly small. Next, the spokes on the non-driving side are used to adjust the left and right yaw and center of the carbon bike rim. Then care about the spoke tension on the non-driving side.
With this program, we can adjust the driving side spokes with high tension less, and weave the carbon bike wheel by adjusting the non-driving side spokes with low tension. The good news is that we don't need violence to twist the spoke cap on the drive side anymore.
It takes about 90 minutes to complete the whole process.