People often sum up the electric bike as “a bike with a motor”. From the wheel's point of view that is wrong: three families of forces rise at the same time, and each one hits a different part of the build.
The three forces that change
These three forces do not add up politely: they combine, and they are cyclic. It is that repetition that wears things out — a spoke almost never breaks in one go, it breaks through fatigue, after tens of thousands of tension-and-release cycles.
What that changes in the build
The number of spokes
Where a light road bike gets by with a reduced spoke count, an e-bike wheel benefits from staying generous: 32 or 36 spokes spread the load over more anchor points, on the rim as well as on the hub flanges. For the most heavily loaded uses — cargo, longtail, tricycle — 36 holes remains the reference.
The crossing
A crossed lacing lets the spokes meet the rim at an angle, and so transmit a rotational force. That is exactly what is needed when torque comes in through the hub. Conversely, radial lacing — spokes running straight from hub to rim — has virtually no grip on torsion: it has no place on a driven wheel.
Tension, and above all its evenness
This is the least understood point. What makes a wheel last is not high tension in absolute terms, it is tension that is even from one spoke to the next.
- Too little tension: the spokes go completely slack each time they pass the bottom of the wheel. The nipples unscrew themselves and the heads break through fatigue.
- Too much tension: it is the rim holes and the nipples that work permanently, and end up cracking.
- Uneven tension: the tightest spokes take the share of the others. They are the ones that give way, and often in series.
A wheel is asymmetric by nature: cassette side at the rear, disc side at the front, the angles are not the same, so neither are the tensions. The balance to be achieved is judged side by side, not overall.
The sign that should alert you
A light metallic clicking that appears when pulling away or climbing, while nothing is rubbing: very often that is the sound of spokes going slack and coming back under load. On an e-bike, that noise almost always precedes a broken spoke. Deal with it early: a broken spoke throws the whole wheel out immediately.
The case of cargo bikes and longtails
These bikes combine everything: the mass of the bike, that of the motor, that of the payload — and often small diameters front and rear. A reduced diameter shortens the spokes, which makes the wheel stiffer but also less forgiving: it absorbs less and passes more on to the build. This is the context where spoke count, crossing and tension evenness matter most.
Why this matters for a reconditioning
When an e-bike rim is beyond use, the temptation is to replace it with “the same thing”. But rebuilding an electric bike wheel with the lacing of a city wheel of the same diameter means reproducing exactly the build that has just failed. That is why the order form asks for the bike's actual use — city e-bike, e-MTB, cargo-longtail — and not only measurements.
The check to make before sending
Our lines work with J-bend spokes, on aluminium rims. Straight-pull — straight head, no elbow — is found mainly on high-end road and mountain wheels, far more rarely on production electric-assist bikes. In the vast majority of cases, an e-bike wheel can therefore be reconditioned in our workshops.
The check takes five seconds: look at the spoke heads at the hub. Bent at a right angle, all good. Straight, fitted into a hole passing through the flange, we cannot rebuild it — no more than a carbon rim.
Three habits that make an e-bike wheel last
- Check the tension after the first few hundred kilometres following a new build: that is when a wheel settles.
- Squeeze the spokes in pairs every two or three months. A spoke clearly slacker than its neighbours gets retensioned before it breaks, not after.
- Do not keep riding a bike with a broken spoke. On an e-bike the wheel goes out of shape far faster than you would think.
An e-bike wheel to recondition?
State the bike's actual use on the form: it is what determines the lacing and the tension. Back within 48 to 72 hours, return carriage included.
