Keeping cool under braking: Nissin and Showa partnership aims for more efficient caliper concepts

Suspension heavyweights Showa are teaming up with brake experts Nissin to develop new, more efficient technologies for both systems.  

Both companies are owned by Japanese automotive tech brand Astemo, opening up intriguing opportunities for suspension and brakes to be co-developed in a way that improves both sets of components.

Astemo – standing for ‘Advanced Sustainable Technologies for Mobility’ – is a combination of Showa, Nissin and fuel injection maker Keihin, and was set up in 2021 by electronics giant Hitachi and Honda.

Each own 40% of the resulting company, with the remaining 20% in the hands of private equity company JIC Capital, and that means Honda in particular is in a position to benefit from systems that are cohesively developed by the three brands under the Astemo banner.

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The idea of combining forks and front brake calipers into a holistically designed unit was explored with Astemo’s ‘Harmonized Function Design’ concept, unveiled at last November’s EICMA trade show in Milan.

Since then, patent applications have been published showing how some of the same ideas could be carried across into a production fork and brake system.

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The Harmonized Function Design concept features a four-piston front brake caliper that’s made as a single unit combined with the bottom of an upside-down fork.

Machined from a block of aluminium, the resulting component is said to be 200g lighter than a conventional, separate fork bottom and brake caliper – likely helping with things like acceleration and changes of direction.

It also promises better heat dissipation from the brake, with the one-piece design acting as an improved heat-sink – increasing the contact area between the brake caliper and fork bottom by 30% and reducing average caliper temperature by a claimed 5%.

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While the Harmonized Function Design concept is an illustration of what’s possible and has drawbacks – largely the fact that the caliper can’t be removed, making the prospect of brake maintenance and pad changes more difficult – Astemo’s patents show a more realistic, production-style version of the idea.

The patents focus on an element of the concept’s design that Astemo hasn’t trumpeted: an opening in the front of the fork bottom, allowing air to pass above the axle and directly at the finned brake caliper to improve cooling.

It’s this idea that the patents explore, showing several variations on the same system in considerable detail.

Unlike the EICMA concept, the patents show a system with conventional, removable, radial-mount brake calipers, but with the added air passage and delicate, open-sided castings for the brake caliper brackets.

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These can be used as they are, allowing cooling air to take a straight path to the brake caliper, or in combination with additional cooling ducts or finned surfaces attached to the outside of the caliper brackets to further control the airflow.

Other variations illustrated in the patent filing include a version with a blade-like structure holding the front axle to the fork bottom, again clearing more of the space in that area for airflow to reach the brake calipers, and a version with enclosed sides to the caliper brackets forming a simpler, stronger structure that still directs air at the brakes.

The increasingly complex brake ducting appearing on modern MotoGP and World Superbike machines shows how important cooling is in this area, and road bikes like CFMoto’s 675SR-R are already adopting similar elements, so it’s clearly an area that companies are exploring for potential improvements in the future.