Main Take Away:
- If your brakes feel soft or spongy, perform our quick and easy Air Bubble Clearing procedure - video below.
- Don't operate the brake levers when the Gocycle handlebar is in a folded position.
- Don't open the brake system or attempt to bleed the brakes.
Gocycle brakes are different from other bikes
Gocycle hydraulic brakes are different from mountain bike or road bike hydraulic brakes because the Gocycle is a foldable bicycle. Here are some important differences:
- When the handlebar is folded down, the brake levers and oil master cylinder reservoirs are turned upside down.
- When the Gocycle is transported or stored in a folded position for a period of time and especially if the levers are pressed when the Gocycle handlebar is folded, tiny air bubbles can move from the oil reservoir into the brake hoses and up to the highest point (the handlebar fold joint) which can make the brakes feel soft or spongy.
- Therefore, avoid operating the brake levers when the handlebar or frame is folded.
- The front brake hose on a Gocycle is shorter and more direct than the rear brake hose; so the rear brake on a Gocycle will generally not feel as firm as the front brake.
- Hydraulic brakes have two main feelings when pulling the levers: a) a "bite point" where the brake pads touch the rotor, and b) “firmness” or "sponginess" after the bite point.
- The bite point on Gocycle brakes is generally around 50% (half way) through the full lever operation. This is optimal for a city bicycle, but will feel different from a mountain bike.
- Brakes that feel more firm will have less tiny air bubbles in the system than brakes that feel less firm or spongy.
- The Gocycle brake hoses have special coils and loops in order to allow the hoses to stretch during folding. These coils and loops makes brake bleeding more challenging on a can trap micro air bubbles more easily than brake hoses that don't have coiled and loops.
- Whether the brakes feel firm or spongy is not an indication of the minimum safety standard of the brakes.
- Gocycle’s standard for safe brakes fit for purpose is when the lever doesn’t touch the handlebar when a 5 kg/11 lb force (like carrying a 5-liters of bottled water) is applied to the lever.
Fixing Spongy Brakes:
If on your pre-ride check, the brakes do not meet the minimum safety check, follow the quick and easy Air Bubble Clearing process as shown below to bring your brakes back up to minimum safe operating standards. This may take a few minutes of constant operation of the levers, and in some cases more than 100 lever pulls. There should be no need to open the brake system to add oil or bleed the brakes.
Deeper Tech Dive
Below is a cross section of the Gocycle brake lever master cylinder and oil reservoir which is typical of most modern hydraulic brakes. When the lever is pulled, the piston will move in the direction of the green arrow and will draw oil from the reservoir forcing it through the outlet to the brake hose which will pressure brake pads to close and slow the disk rotor. Generally, hydraulic brake systems will have some amount of tiny air bubbles in the oil reservoir. Due to the orientation of the lever, these tiny bubbles will settle at the highest point of the brake lever master cylinder shown in the pink areas. These tiny air bubbles will remain in this location and will not be pulled into the brake line hose unless the brake lever master cylinder is turned upside down - for example when the handlebar is folded.
If when the handlebar is folded as shown below, the master cylinder is upside down and the air bubbles can float up from the pink areas in the direction of the red arrows. Over long storage or transport and especially if the lever is lever is operated while the master cylinder is upside down, air bubbles can be pulled through the filler ports into the main piston cylinder and then into the outlet to the brake hose. This will make the brakes feel soft or spongy.
To fix this, do not open the brake system or attempt to bleed the brakes, instead, perform the quick and easy Air Bubble Clearing procedure as shown here.
Brake Bleeding
We do not recommend bleeding the brakes or opening the brake system unless you are extremely experienced and patient and have proper bleeding syringes. 9 times out of 10, brake softness or sponginess is due to storage, transport, or pressing the levers while the handlebar is folded and this can be recovered using the Air Bubble Clearing process. For the reasons explained in this article and the special design of the Gocycle to enable it to fold, it is not reasonable to expect that the Gocycle brakes can achieve consistent feel levels similar to mountain bikes or racing bikes. Only after doing the Air Bubble Clearing procedure, if the levers fail the 5 kg / 11 lb safety check or pre-ride checks should you contact Gocycle or your local dealer for advice.