Carbon fiber material has been widely used in bicycles since its adoption. Furthermore, carbon spokes have also appeared, so what about carbon spokes? This time, we will introduce the advantages and disadvantages of carbon spokes.

Advantage 1: Lighter weight

Taking a certain brand of carbon spokes as an example, five 290 mm long carbon spokes were selected, and the total weight was 16.2 g, with each spoke averaging 3.24 g. Carbon spokes also require dedicated spoke nipples, and titanium alloy spoke nipples weigh 3.2 g.

For the well-known Sapim CX-Ray spokes, five spokes of the same 290 mm length have a total weight of 24.4 g, with each spoke weighing 4.88 g. Sapim round nipples weigh 3.9 g, and Polyax nipples weigh 3.6 g.

Carbon spokes are only 65% the weight of steel spokes. Since carbon spokes have metal fittings at both ends, the shorter the spoke length, the smaller the weight difference.

In the case of a wheelset with a total of 44 spokes (20 front/24 rear), carbon fiber spokes can provide a weight advantage of about 90 g in spoke weight, which is a considerable difference.

Advantage 2: Higher tensile strength

Carbon fiber has higher tensile strength in specific directions than metal. Therefore, to achieve optimal tensile strength, carbon spokes are basically arranged radially with UD unidirectional fabric.

Here, we introduce a comparative experiment. The test used Sapim D-light spokes with a variable spoke diameter of 2.0-1.65-2.0 as the control group.

Again, no two spokes are identical, and it can be seen that the tolerance deviation of handmade products like carbon spokes is greater than that of steel spokes.

All five tested carbon spokes had damage strengths above 350 kgf, which was higher than steel spokes.

From the data, it can be seen that for forces within 1000 N (approx. 100 kgf), the change in carbon spokes and steel spokes is consistent, but when it exceeds 120 ± 10 kgf, the distinction between drive-side spoke tension/front disc brake-side spoke tension begins to appear. At high tensile forces, spokes are more prone to stretching, but carbon spokes consistently maintain their tensile strength.

When pedaling, the tensile force on some spokes is higher than the pre-set tensile force during wheel assembly, and the elongation of steel spokes is greater than that of carbon spokes.

This is also why major factories do not choose to increase spoke tension, and it is also the direct reason why carbon spokes provide a better feeling of power generation when riding a bicycle.

There are advantages, but there are also disadvantages. We will now introduce the disadvantages.

Disadvantage 1: Custom hub required

Excluding integrated, one-piece carbon spoke assemblies, most carbon spokes currently on the market have a different shape than steel spokes and cannot be directly used with regular hubs for assembly.

Disadvantage 2: High damage rate

It is a well-known fact that carbon spokes are more prone to breaking. Due to the characteristics of carbon, it is weak against external impacts, so if a crash occurs, carbon spokes are more likely to break.

Therefore, wheels that are not one-piece solve this problem somewhat. Even if some spokes break, you only need to replace those few, and the entire wheel does not need to be discarded. However, spoke adjustment becomes an issue when replacing spokes.

Furthermore, the bonding method used by some brands for carbon fiber spokes and metal nipples is epoxy resin bonding, which is susceptible to oxidative degradation, meaning gumming up and coming loose. Especially in the case of regular tension wheelsets, if the spokes are subjected to a tensile force of around 100 kgf for a long period, their lifespan will be shortened.

Disadvantage 3: Reduced comfort

An increase in spoke tensile strength has the adverse effect of reducing comfort. This problem applies to both aluminum spokes and carbon spokes. The reduction in comfort is noticeable in the feedback from small road vibrations during riding, and coping with this problem requires greater physical strength and control ability.

Disadvantage 4: High price

This is said to be the most significant drawback. In fact, the high price itself isn't the drawback. Both manufacturing costs and R&D costs are higher, leading to higher selling prices.

The above is a brief analysis of the advantages and disadvantages of carbon spokes. If you are buying spokes, would you choose carbon spokes?