Matt Robinson profile picture Matt Robinson 3 years ago

What The Hell Is A 'Monoblock' Brake Caliper?

You've probably heard of a 'monoblock' caliper before, but what makes it different to the more conventional alternative?

Remind me later
What The Hell Is A 'Monoblock' Brake Caliper? - DIY

When a manufacturer brings out a faster, sharper version of a car, you’ve probably heard the term ‘monoblock calipers’ used. Or perhaps you’ve been furiously scanning through a parts catalogue and have seen the word crop up. But what does it actually mean?

Firstly, we have to look at the construction of a conventional multi-piston caliper. Since it squeezes in two pads - one from either side - it needs two ‘faces’, each with piston bores and fluid tracts machined into them. The easiest way to do this is to make two halves and bolt them together, creating what’s sometimes referred to as a two-piece caliper.

A conventional two-piece brake caliper. Note the seam down the middle and the bolts holding the two sides together
A conventional two-piece brake caliper. Note the seam down the middle and the bolts holding the two sides together

The only problem is this design is inherently compromised. Energy is wasted as the force of the pistons pressing in the pads tries its best to force the two pieces of the caliper apart, creating something known as ‘caliper flex’. The result is a loss of some braking feel and uneven pad wear. However, the latter problem can be mitigated by upping the piston count (four and six-piston arrangements are common, and some setups even use eight) to spread the braking force more evenly.

One option to tackle caliper flex is with a monoblock caliper. Made from one piece of material (hence ‘mono’), a monoblock caliper is more fiddly to make, as there’s only a small space in between the two sides of the part for the necessary holes to be machined. But, this kind of design will be - theoretically at least - stronger and more resistant to flex. Hello improved brake feel and more even pad wear.

What The Hell Is A 'Monoblock' Brake Caliper? - DIY

CNC machining is the most typical way for one of these calipers to be manufactured, but there are other methods. Bugatti for instance 3D prints the Chiron’s gigantic brake calipers - the largest fitted to any production car - from titanium. Each is made over 45 hours, during which time 2213 layers of titanium powder are laid down and melted with lasers before the part is heat treated and milled to create the beautiful object you see above. Fancy.

Monoblocks are all well and good for well-resourced manufacturers and for the precise world of motorsport, but what about for your own ride? Should you go out and buy monoblock calipers immediately, to avoid the dreaded caliper flex?

That’s not a question that can be broadly answered without delving into specific circumstances, but it’s safe to say that any improvements aren’t going to be felt dramatically. If funds are limited, a pad upgrade is much more likely going to make a meaningful difference to the way your brakes feel and operate.