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

Overview of the BD9 mid-motor conversion

Arrowmax delivers a conversion package that repositions the motor on Yokomo BD9 chassis into a mid-motor layout so drivers can explore different handling responses. The kit bundles components that modify motor placement, upper deck profile, pulley layout and overall chassis stiffness to let tuners evaluate handling without altering the BD9 core gearbox.

The main items in the release include the option of a 2.25mm carbon fibre chassis or a 2.0mm 7075 alloy chassis, a 2.0mm carbon fibre upper deck, a one-piece 7075 motor mount and updated 7075 centre pulleys, along with a chassis stiffener that provides selectable flex positions. Changing to mid-motor has a noticeable effect on steering balance and cornering behaviour when applied to BD9 models.

Ideal for experimenting with weight bias and flex tuning, the conversion is used when adjusting front/rear load distribution or when aiming for stronger corner entry response. Installation follows normal BD9 disassembly to swap chassis panels and motor mount parts and to re-establish pulley and belt geometry in the new layout.

The kit suits BD9 racers wanting a repeatable method to trial mid-motor geometry and chassis flex permutations without having to machine custom parts, providing matched structural and drivetrain pieces for setup work.