Spokes are an essential part of any bicycle, all the more for ebikes, because they have to bear more weight and transmit more power to the ground, also turning faster. Quality spokes make a difference. When choosing an ebike, you may want to verify the quality of its spokes, some brands being a guarantee. Spokes of cheaper ebikes can often result in twisted rims after a few thousand kilometers.
Spoke number matters, but only to a certain extent
The number of spokes one can find on bike and ebike wheels can be 3 to 6, or 20, 24, 28, 32 or even 36. Although it’s true that more spokes entail more stability of the wheel, nowadays wider rims have lessened the impact of their number on wheel stability and rim resistance.
Soft rims require more spokes
Older bicycles had narrower rims compared to today’s wheels. Therefore, in order to compensate for their fragility, as many spokes as possible where deployed. Numerous spokes are not necessary when the rim is narrow and flat.
Influence of construction and materials
The stability of the wheel doesn’t depend solely on the number of spokes, but also on the width of the rim and its material. High rim profiles are more torsion-resistant than flat ones. The higher and/or the wider the rim (especially in the case of high-profile road bike rims and wide MTB rims, for example), the stiffer it is. Moreover, fewer spokes imply less weight and less aerodynamic resistance. For cargo and ebike rims in particular, a secure wall guarantees more robustness and stability, even more than a high number of spokes, which is thus less relevant. Just 28 spokes can provide very stable and robust ebike and cargo wheels, especially if they are built with the adequate materials. This consideration is supported by the fact that the wheel manufacturer DT Swiss has discontinued the production of its Hybrid E-Bike H 36 spoke wheel.
Six spokes inexpensive ebike
Ebikes with 4 to 6 spokes
They sure may look nice, depending on one’s taste. That notwithstanding, we are not convinced that they are a good choice. Spokes have a certain flexibility, what helps the ebike and the rims absorb shocks and bumps. Very few spokes must be more rigid, because they are way thicker. If one of those few spokes breaks or get twisted, you have to replace the whole wheel, what can be very expensive with certain hub motors. If few spokes were such a good option, why all racing bicycle and ebikes always feature more than six spokes?
Spokes problems and remedies
Rust
Spokes can rust, unless they are built with quality stainless materials. If the rust is only superficial, you can take it away applying some Diet Coke with a paintbrush. If it’s deep, you can buy some anti-rust products that eliminate rust, but if it’s too deep, you’d better replace the spokes or the wheel. If you have to resort to a workshop, keep in mind that, sometimes, replacing the spokes takes a lot of time, thus is more expensive than purchasing a whole new wheel,
Twisted rims
Losen or unevenly tightened spokes can result in twisted rims. That’s why you should regularly check out your spokes, normally every couple of thousand kilometers, tightening them if they are too lose.
Checking the rims
Tightening and centering the spokes
Spokes tend to losen and so you have to tighten them every now and then, mostly every couple of thousand kilometers for a city ebike, more often for an e-mountain bike.
First, to verify their tension, pinch them as if they were guitar cords: their sound should be high-pitched, otherwise they are lose or not tense enough. You can also pinch two of them at a time, to check if they are tense enough. It should be hard to even slightly flex them. For a thorough check up, put your bike upside down, firmly set on the chain stay a pencil or any stick, like in the picture above, and turn the wheel. If the rim touches the pencil at some point, you should tighten the spokes on the other side (spokes are either more to the left or more to the right side of the rim). With a tool like the one in the photo, choose the right measure, then turn clockwise (looking from above the wheel) the spokes that you want to tighten, but not more than 1/4 of a tour. Turn again your wheel to see if it turns straight.
Spoke spanner
With carbon wheels, you have to loosen all the spokes to centre them and tighten them again.
Replacing bent or broken spokes
Replacing the spokes on the front wheel of a bicycle is much easier than on the rear wheel. Replacing the spokes is particularly complicated if they are broken on the side of the sprocket set. You must remove the entire sprocket in order to change the spokes. Even if it doesn’t seem necessary, we recommend that you remove the entire wheel and take off the tyre with the inner tube. Simply inserting a new spoke is not enough to get the bike rolling properly again. After replacing the spokes, it is extremely important to centre them so that the wheel runs smoothly. You will need to remove the inner tube and rim tape for this operation so that you can reach the spoke nipples.
Step by step:
- Once you have removed the damaged wheel, you can now unscrew the broken spoke from both the hole in the hub flange and the spoke nipple.
- Now you can insert the new spoke. When buying spokes, make sure that they are of the same type and that they are the correct length. First insert the bent spoke head through the hole in the hub flange.
- Then you have to connect the other end of the spoke to the spoke nipple. To do this, guide the sleeve of the spoke nipple through the hole in the rim, twisting it firmly onto the end of the spoke by hand. Depending on the design of the spoke nipple, you may need a slotted screwdriver or a small hexagon spanner. However, the actual tensioning of the spoke is done afterwards with the spoke spanner.
- If you have to change several spokes on your bike, make sure that the spokes are in the correct position. You can use the position of the neighbouring spokes as a guide. The penultimate spoke shows you how to fit the spoke. Avoid bending the new spoke too much.
- Before you centre the bicycle spokes, briefly check the following: are the spokes still correctly seated in the holes in the hub flange? Have you also inserted the spokes correctly so that the arrangement of the spokes is even and no spoke falls out of the pattern? Does the nipple head sit properly at a right angle in the hole in the rim? Are all spokes firmly connected to their spoke nipples?
Once you’ve completed this quick check, you are ready to centre the bicycle spokes.
Spokes, a century-old technology
As a conclusion, isn’t that fascinating that spokes have been around for more than a century, and there still the best choice for bicycles and ebikes wheels?
Images: KTM, Samebike