• AST/MOTON is a Netherlands-based manufacturer dedicated to building suspension solutions for high-end European street cars and championship-winning race teams alike.
• While it has primarily been known for its well-engineered coilover systems, both AST and MOTON product lines have swelled to include a wide array of complementary parts like camber plates, lowering springs, and control arm bearings.
• MOTON’s BMW front control arm bearings (FCAB) are robust, plug-and-play replacement items that provide much more direct steering feel than their rubber OEM counterpart.
• The parts — which are available for E9X, F8X, G20 3-Series, and G8X M cars — have spent five years actively participating in the BMW M240i Racing Cup for true motorsport testing.

“We don’t go to our deathbeds remembering all the great emails we’ve sent.” It’s something that Kevin McCloud, the charismatic host of Grand Designs, a British home-building show, said on one of my recent weekend binge sessions. It struck a chord with me as someone who writes a not-so-insignificant amount of carefully drafted emails, but also as a person who admires craftsmanship, detail, and the pursuit of engineering excellence into a living, breathing entity. 

Indeed, McCloud’s point is that, at the end of our lives, we measure ourselves (or are measured by) the things that we create. Perhaps consciously, the show is biased toward bespoke, highly creative works. Each finely tailored home is predicated on innovation and as such, intends to create the best possible solution for its occupants without compromise.

BUILT TO WIN

AST Suspensions is a lot like that. The company—which manufactures both AST and MOTON products—has dedicated its operations to enthusiasts who demand tailored solutions. That commitment earned AST/MOTON a seat at some of the highest tables in motorsport, including FIA GT, ETCC, WTCC, and Sportscar Championships where it consistently propelled its entrants to victory. This pinnacle success is AST/MOTON’s passion, akin to the halo home that Grand Designs is known for highlighting. But similar to how a truly great architect can create bespoke works and functional spaces for the masses, AST/MOTON’s tenured maturity came from a similar duality: translating its on-track success to the everyday enthusiast.

Indeed, over time, that motorsport technology found its way into the consumer market. Specific kits, many of which we admire today, were created to mesh discerning motorsport demand with turn-key street car solutions. Eventually, AST/MOTON’s street car catalog swelled to meet ever-widening consumer demand: lowering springs, Adjustable Lowering Spring (ALS) kits, camber plates, and monoball control arm bearings all became valuable add-ons to the company’s repertoire.

The unsuspecting last item on that list is what brings us here today. While it won’t give you the aesthetic benefit that coilovers can, it offers an equally significant improvement in the way the car drives. The large impact the MOTON pieces deliver has a lot to do with one big thing: switching from a bushing to a bearing.

BUSHING VS BEARING

From the factory, the control arm houses a bushing: a simple, non-moving component that enables movement via material compression. This bushing, made from flexible rubber, acts as a barrier between metal parts, absorbing the brunt of road vibrations, bumps, and potholes in the name of preserving ride quality. However, the same material used to maintain comfort is also responsible for inaccurately translating driver input to the front wheels. As a result, the OEM steering feel is vague and often does not provide the crisp confidence that enthusiasts desire.

MOTON’s revision is a spherical bearing assembly. By contrast to their bushing counterparts, metal bearings are moving parts that enable continuous rotation thanks to their multi-piece construction. The prominent, fixed orange “ring” affixes to the factory control arm via the included snap ring. Crucially, rotation is achieved via the centralized roller element within the metal bearing, not by flexing the material itself. By replacing the OEM, soft rubber bushing with a solid aluminum bearing assembly, the amount of steering deflection is virtually eliminated.

MOTORSPORT PROVING GROUND

MOTON’s tie with professional motorsport sets it apart from other manufacturers. In fact, the MOTON control arm bearing has been actively participating in wheel-to-wheel action for over five years. The BMW Racing Cup, an M240i motorsport series that races between Belgium and the Netherlands, has fitted its entire field with MOTON control arm bearings (and AST 5100 coilovers for good measure). It’s only recently that AST/MOTON decided to turn its bespoke racing component into a readily available consumer piece.

“We have been testing these in the M240i Championship and they go through a lot of sprint racing, 24-hour endurance racing, and track day sessions,” said Coen de Korte, CEO of AST/MOTON. “Most of these vehicles have been tracking over 12,000 miles on our AST 5100 suspension kits and MOTON front control arm bearings!”

QUALITY AND QUANTITY

The reason the MOTON BMW control arm bearings can stand up to those aforementioned rigors comes down to their build quality. Each set is constructed from aircraft-grade aluminum and anodized in the brand’s signature orange color for wear resistance. The lightweight aluminum hats that protrude from each end of the large center bearing are beautifully machined, too, and seat snugly within the bearing’s cavity. A carbon-composite press-in tool is also included to make installation straightforward since tolerances are designed to be tight.

Thankfully, this component isn’t just for the race-bred M240i that spurred its creation. At launch, the MOTON control arm bearing sets are available for a wide range of applications, including the E9X (76DB-E9X-A3-101S), F8X (76DB-F8X-A3-101S), G20 3-series (76DB-G2X-A3-101S), and the G8X (76DB-G8X-A3-101S). Each chassis stands to benefit greatly from this upgrade, either as a standalone item or in conjunction with a set of AST/MOTON coilovers.

Although the company has amassed plenty of motorsport accolades already, AST/MOTON’s work here tallies another mark toward its lifeline’s creations. Here, it’s managed to create a product that provides equal benefit to both motorsport and real-world usage cases. It’s a finesse that AST/MOTON is refining every day and the fruits of that labor will only continue to extend the brand above its competitors. 

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