What are Brake Lines?
The hoses or hard pipes that carry pressurised brake fluid from the master cylinder to each caliper.
Simplified animation — not to scale.
In plain English
Brake lines carry hydraulic fluid under real pressure from the lever or pedal to the calipers. Many bikes use braided steel lines for a firmer, more consistent lever feel than the rubber originals.
“The bike's nervous system for braking — carrying the signal, fluid pressure, instantly from input to action.”
How it works
Fluid is essentially incompressible, so pressure applied at the master cylinder transmits almost immediately through the lines to the caliper pistons. Rubber lines can swell slightly under pressure, softening lever feel; braided lines resist that expansion for a firmer response.
Signs of trouble
- ⚠Visible cracking, bulging or wear on the outer hose
- ⚠Fluid leak or wet patches along the line's routing
- ⚠Spongier brake feel than usual
- ⚠Failing an MOT brake line inspection
£60–£250
Always get a written quote. Prices vary by bike, region, and parts brand.