Fatbike brake not working properly: soft lever or poor braking power

By the Sache Bikes workshop · updated 17-10-2026

If your fatbike's brake feels soft or doesn't stop you well, worn or contaminated brake pads, air in a hydraulic brake, or a stretched brake cable are usually the cause. First check the brake pads and brake disc, and do not continue riding if the brake lever almost reaches the handlebar. Repairs can be carried out in The Hague and Zoetermeer, often on the same day.

In short

• Spongy lever on a hydraulic brake: usually air in the system or old brake fluid. Solution: bleed the brakes and replace the fluid.
• Lever pulls far on a mechanical (cable) brake: the cable is stretched or the pads are worn. Solution: adjust or replace.
• Firm lever but little braking power: often contaminated or glazed brake pads or a greasy brake disc.
• A poorly working brake is a safety issue: do not ride it in traffic.
• Replacing brake fluid costs €25, a complete brake set €120 (estimated price incl. installation).

Most common causes

Worn brake pads

When the brake material is almost gone, the pistons or brake arm must move further before the pad touches the disc. The lever pulls further and the braking power decreases. With completely worn pads, the metal backing rubs against the disc; you can hear this as a metallic scratching sound. Read more in fatbike brake pads: when to replace.

Air in a hydraulic brake

Hydraulic brakes work with oil in a closed system. If air gets in, for example due to a small leak, a damaged hose or after incorrectly pushing the pistons back, the lever becomes spongy: you can squeeze the lever without a clear pressure point. Old brake fluid can also perform less effectively over time. Bleeding and replacing the fluid usually solves this. More explanation can be found in bleeding fatbike hydraulic brakes.

Stretched brake cable on mechanical disc brakes

Many fatbikes have mechanical disc brakes with a cable. That cable stretches slightly during the initial period, and the pads wear out. You will notice that the lever pulls further and further. Often you can adjust this with the adjustment screw at the brake lever or the brake caliper. A rusty or stiff cable must be replaced.

Contaminated brake pads or brake disc

Oil, chain spray, polish or grease on the brake disc causes the pads to have hardly any grip. The lever then feels firm, but the bike stops poorly and the brake often squeaks loudly. Contaminated pads usually need to be replaced and the disc must be degreased with brake cleaner.

Warped disc or misaligned brake caliper

A warped brake disc or a brake caliper that is not properly aligned causes the pad to engage only a small part of the disc. You often hear a rhythmic rubbing sound and the braking power varies per revolution.

Defective brake sensor

The brake levers of an e-fatbike usually contain a brake sensor that switches off the motor as soon as you brake. If that sensor does not work, the motor can continue to push for a while while you brake, making it seem as if the brake works poorly. Conversely, a stuck sensor can cause the motor to stop assisting completely.

Check yourself: step by step

1. Squeeze both brake levers firmly while the bike is stationary. Note which brake feels soft or pulls far.
2. Look in the brake caliper how much brake material is still on the pads.
3. Inspect the brake disc: is it shiny and clean, or greasy, discoloured or grooved?
4. Spin the wheel and see if the disc runs straight through the brake caliper without rubbing.
5. On a hydraulic brake: look for oil on the hose, at the brake lever and around the brake caliper.
6. On a cable brake: turn the adjustment screw at the brake lever out a little and test again. If that does not work, have the brake adjusted.
7. Test in a quiet place at low speed or whether the bike stops properly before you go back on the road.

When to go to the workshop?

Go directly to the workshop if the brake lever almost reaches the handlebar, if you see oil leaking, if the motor continues to push while you brake, or if the brake still works poorly after new pads. Bleeding requires the correct oil (there are systems based on mineral oil and on DOT fluid, which you must never mix) and the correct tools for each brand. Brakes are the most important safety component of your bike: if in doubt, have it checked.

Repairs in The Hague or Zoetermeer

Estimated prices incl. VAT and installation, excluding any parts unless stated otherwise. The inspection fee of €30 is waived if we carry out the repair. If more is needed, we will discuss it first; we never do anything without consultation. Home repairs are also possible, excluding travel costs.

We test the brakes, determine the cause and discuss the price before we start. After the repair, we take a test drive to check if the brake engages properly and the motor switches off properly when braking.

• The Hague (Calandkade 44-45, Mon-Sat 10:00-18:00): Brake repairs in The Hague, Maintenance service in The Hague.
• Zoetermeer (Philipsstraat 3B, Mon-Sat 10:00-18:00): Brake repairs in Zoetermeer, Maintenance service in Zoetermeer.

Via making an appointment, you choose the repair and see the total price; you send the request via WhatsApp. You can also call: +31 85 060 9232. We repair brakes from all common brands, even if your bike was not purchased from us.

Ordering parts yourself

Brake pads, brake discs, brake levers (with or without sensor) and complete brake sets can be found at brakes for fatbikes. Other parts are listed under fatbike parts. Delivery in 1-3 business days for €8.95, free from €125, or free pickup in The Hague or Zoetermeer.

Also read: fatbike brakes squeak.

Frequently asked questions

Why does my hydraulic brake feel spongy?

Usually there is air in the system or the brake fluid is old. Bleeding and replacing the fluid often solves this. Replacing brake fluid has an estimated price of €25 incl. installation.

My brake lever reaches the handlebar. Can I still ride?

No. Then the braking power is insufficient to stop safely. Have the bike checked or bring it to the workshop as is.

How do I know if I have hydraulic or mechanical brakes?

If there is a cable in an outer cable to the brake caliper and there is an arm on the caliper where the cable is attached, then you have mechanical brakes. If there is a smooth hose without a loose cable and a reservoir at the lever, then it is hydraulic.

Can I top up the brake fluid myself?

Only if you know exactly what type of oil your brake uses and how to bleed it. Mineral oil and DOT fluid must never be mixed; the wrong fluid damages the seals.

Why does my fatbike brake poorly after cleaning?

Probably some cleaning agent or chain spray got on the brake disc. Degrease the disc with brake cleaner. If the pads are also contaminated, they must be replaced.

What does a brake sensor do on an e-fatbike?

The brake sensor switches off the motor as soon as you brake. A defective sensor can cause the motor to continue pushing during braking or not assist at all. Replacing the brake sensor costs €25 (estimated price incl. installation).