YOKOMO BD9 Mid-Motor Conversion Kit - Arrowmax AM-910003  [AM-910003]

BD9 mid-motor conversion overview

This Arrowmax conversion kit adapts the Yokomo BD9 platform into a mid-motor layout to help racers explore different balance and handling settings. The package groups parts that change motor position, upper deck geometry, pulley arrangement and chassis stiffness so tuners can compare flex and weight distribution without modifying the BD9 drivetrain itself.

Key elements listed in the original release include a choice between a 2.25mm carbon fibre chassis or a 2.0mm alloy chassis option, a 2.0mm carbon fibre upper deck, a single-piece 7075 aluminium motor mount and revised 7075 centre pulleys, plus a chassis stiffener to allow multiple flex settings. Arrowmax notes the mid-motor shift alters steering feel, traction and corner speed on BD9 machines.

Use the kit to test front/rear balance and chassis flex on BD9 cars, for example when chasing more front-end bite at corner entry or a more neutral rotation mid-corner. Installation follows standard BD9 teardown steps to swap the main chassis and motor mount components and to reroute pulley and belt geometry for the mid-motor arrangement.

The conversion is aimed at BD9 owners who want a controlled way to evaluate mid-motor geometry and chassis flex options without fabricating bespoke parts, delivering a coordinated set of structural and drivetrain components for methodical setup work.