Radial vs Axial Master Cylinders: Differences Explained

Much like radial and axially mounted calipers, the mounting position of master cylinders also affect braking performance. But which one’s a better setup? 

A week ago, we spoke about the advantages and disadvantages of radial and sliding calipers, and how the position of the mounting bolts determines its performance. The exact same principle applies to brake master cylinders, which are of two types: radial and axial. Here are the advantages and disadvantages of each configuration. 

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Mounting position:

In a radial master cylinder, the setup is perpendicular to the handlebar. So when the rider pulls on the lever, the force exerted is transmitted directly onto the piston in the same direction, without friction losses caused by the use of multiple components. Essentially, the configuration applies direct force on the piston which forces brake fluid to the calipers, squeezing the brake pads and making the bike stop. 

An axial master cylinder, on the other hand, applies force to the piston in a swiveling motion (90 degrees by the lever pivot) and makes use of more components to complete the action.

Advantages of radial master cylinders:

Simply put, reduction in flexing of brake parts such as the lever, master cylinder housing, brake lines, calipers and caliper mounts add up to better brakes with better feel (modulation). Besides, radial master cylinders are more often than not made from superior materials and designed to be more rigid. 

Disadvantages:

They are expensive to manufacture and are usually seen on premium motorcycles like the Triumph Street Triple RS or the Ducati Panigale V4 S which use top-spec Brembo Monobloc calipers.

Also Read: Different Types Of Motorcycle Drive Systems

Advantages of axial master cylinders:

Axial master cylinders and calipers are cheaper to manufacture and offer almost the same braking performance as radially mounted ones. 

Disadvantages:

The use of multiple components or moving parts and more travel between the lever and piston results in less feel and feedback through the levers while braking hard.