YOKOMO BD9 Mid-Motor Conversion Pack by Arrowmax AM-910003  [AM-910003]

Mid-motor conversion for BD9 explained

This Arrowmax conversion pack reconfigures the Yokomo BD9 chassis to a mid-motor layout so drivers can investigate alternate balance and handling characteristics. The kit assembles parts that shift motor location, alter the upper deck profile, change pulley layout and modify chassis stiffness to let tuners assess flex and distribution without changing the BD9 gearbox.

Components called out in the announcement include a choice of a 2.25mm carbon fibre chassis or a 2.0mm 7075 alloy chassis, a 2.0mm carbon fibre upper deck, a single-piece 7075 motor mount and revised 7075 centre pulleys, together with a chassis stiffener offering selectable flex settings. The mid-motor layout typically influences steering feel, traction and corner speed on BD9 cars.

Use the conversion to experiment with weight bias and chassis compliance on BD9s, for example to improve turn-in or to reduce understeer at corner exit. Fitting the parts follows standard BD9 disassembly to swap chassis panels and motor mount assemblies and to realign belt and pulley geometry for the new motor position.

The pack is aimed at BD9 owners wanting a modular route to trial mid-motor geometry and flex settings without machining their own parts, providing a coordinated set of structural and drivetrain pieces for focused setup work.