Maintaining an e-bike with belt drive: how to keep it quiet, precise, and reliable
The myth of the belt always ends up collapsing. Not at the time of purchase (because "it's virtually maintenance-free!"), but sometime in February. Wet roads, road salt, a few weeks without thinking about your drivetrain... and suddenly you hear a buzzing noise, or worse: a sharp click when you press hard on the pedals.
And then you realize something: maintaining a belt-driven e-bike does indeed require little work, but it's not zero work. It all comes down to three things: keeping it clean, maintaining the right tension, and ensuring proper alignment. If you master these three points, the belt will remain a silent luxury for years to come that you won't want to do without.
Written by: Jos Mans | January 29, 2025 | Reading time: 5minutes
About the author: Jos Mans
Jos is a writer and cyclist, most often both at the same time. With thousands of miles under his belt and just as many words on paper, he combines his two great passions: being on the move and telling stories.
Key findings
- Never grease your belt. Water and a soft brush are sufficient; "smart" lubricants often make the situation worse.
- Too loose = slippage, too tight = stress on the bearings. Tension is not a matter of feeling: it must be measured.
- After each tension adjustment: check the alignment. Misalignment is the quickest route to unwanted noise and wear.
What you maintain (and why it's crucial on an e-bike)
With a belt drive, you don't maintain "the belt" as an isolated component, but rather as a whole: the belt + the toothed pulleys + the frame tensioning system.
On an e-bike, an additional factor comes into play: torque. A mid-drive motor sends a relatively large amount of force into the drivetrain, making tension and alignment more critical than many people realize.
Another often overlooked detail is that there are different Gates ranges (such as CDN and CDX/CDC configurations), and they are not all designed for the same uses. So check what is written on your belt and pulleys to avoid imposing "light duty" expectations on "heavy duty" use, or vice versa.
The three pillars: cleanliness, tension, alignment
If you remember this, you've already done 90% of the work:
- Cleanliness: a belt operates dry. Dirt must therefore be removed.
- Tension: if too loose, it jumps; if too tight, it creates unnecessary resistance and stress.
- Alignment: the belt must run straight. Misalignment = noise, wear, and frustration.
The advantage of belts: problems are generally consistent. The same noise, at the same time, under the same load. This makes maintenance predictable.
Cleaning: what you do (and what you avoid)
The biggest advantage of a belt is that you don't need to lubricate it. So... don't do it.
To do:
- Rinse and clean with water (preferably lukewarm) after exposure to mud, wet sand, or salt.
- Use a soft brush or cloth to remove dirt between teeth.
- Leave to dry, done.
Avoid:
- Do not lubricate: this attracts dirt and makes the belt noisier in practice.
- No harsh or degreasing cleaners: water + gentleness is the safe bet.
- Do not bend, force, or twist: a belt can be damaged internally without you seeing it immediately.
If you hear a slight squeaking noise, start by cleaning it. It's the cheapest diagnosis there is.
Tension and alignment
This is where things often get complicated, because many people do this "by feel." However, a belt is a system that can be measured very precisely: with a gauge/tester or by measuring the frequency (Hz) using an app by "pinching" the belt.
Practical reflexes:
- Slippage during heavy acceleration (starting, hills, rapid acceleration): generally too loose or teeth area clogged.
- Heavy feeling or mechanical noise like rolling: may indicate excessive tension.
And the most important rule: after each tension adjustment, check the alignment. To do this, look at the belt from behind and slowly turn the cranks. The belt should remain stable and straight, without "walking" to one side.
Problems and wear and tear: when to intervene
- Noise: Buzzing: often tension or alignment. Squeaking: most often dirt (clean first). Ticking: check for a stone or damaged tooth/pulley.
- Skating: Clean first, then measure and adjust the tension, then check the alignment.
- If the problem persists with a central motor or high torque, head to the workshop.
- Wear: Replace if there are cracks, missing teeth, visible internal fibers, or clearly worn pulleys. After a fall or transport: if in doubt, have it checked or replaced as a precaution.
My advice: make belt maintenance truly low maintenance.
- Normal daily runs: Quick check/flush every week; tension measurement + alignment check once a month.
- Winter, salt, sand, or heavy loads: Quick rinse after wet or salty conditions; every two weeks, tension + alignment.
- Who it's for: You want to drive cleanly and quietly, and don't mind measuring once a month.
- For those who haven't done it yet: You want zero control and ultimately prefer to be in a car.
FAQ
Is a belt drive really maintenance-free?
No. "Low maintenance" is the honest term. You don't lubricate it, which saves a lot of time, but you do need to keep the belt clean and check the tension and alignment from time to time, especially on mid-drive e-bikes.
Can I clean my belt with a degreaser or chain cleaner?
Preferably not. Just use water and a brush or soft cloth. Harsh products are unnecessary and can undermine the "dry and clean" principle.
How can you tell if the belt is too loose?
The clearest sign is wheel spin during hard acceleration, for example when starting off, on hills, or during rapid acceleration. Clean first, then measure and adjust the tension.
How can you tell if the belt is too tight?
You may feel extra resistance ("the bike feels heavier than usual") or hear mechanical noises coming from the hub or bearings. Too tight = unnecessary strain. Measuring avoids guesswork.
When should the belt or toothed pulleys be replaced?
In case of cracks, missing teeth, visible internal fibers, or clearly worn tooth profiles on the pulleys. And after a fall or damage during transport: if you are unsure, have it checked or replaced as a preventive measure.