Build and Kill Zombies: How to Build a Motorcycle That Won’t Flip

A two-wheeled motorcycle is one of the trickiest things to build in Build and Kill Zombies because the physics engine flips any inline bike the moment you steer. The build itself is short. The part that actually keeps it upright is a pair of low side supports mounted next to the fuel tank, and without them the whole thing rolls over before it clears the first zombie.

Quick answer: Build an inline frame with a Cloudrunner Wheel in front and a Titan Wheel in back, then mount two Metal Spikes (or Armored Cylinders) low on both sides of the fuel tank so they catch the ground on leans and stop the bike flipping.

Parts you need before you start

Roll these from the CAR PARTS machine first so you are not stopping mid-build to hunt for a piece. Weight matters on a bike because the frame is so small, which is why the body uses light carbon fiber. The engine is the one heavy part on the whole rig.

Part	Role	Weight	Durability
Cloudrunner Wheel	Front wheel	6	120 HP
Titan Wheel	Rear wheel	6	160 HP
Carbon Fiber Block	Spine / body	2	140 HP
Carbon Fiber Slab	Base + fender	1	110 HP
Carbon Fiber Wedge	Nose + rear fender	1	110 HP
Double Wing	Under-frame	1	100 HP
Pro Wing	Handlebars (x2)	1	100 HP
Hood Scoop	Front fairing	1	200 HP
Rocket Turbo	Frame insert	4	120 HP
Turbo Fuel	Fuel tank	6	100 HP
Driver Seat	Seat	1	100 HP
Scarlet X	Engine	15	170 HP (Speed 40)
Twin Exhaust	Rear detail	3	150 HP
Metal Spikes	Stabilizers (x2)	2	100 HP

You can swap the Twin Exhaust for a Carbon Fiber Slab and the Metal Spikes for Armored Cylinders without changing how the bike handles. The spikes and cylinders both do the same stabilizing job.

Open Build Mode and clear the plot

Press B to enter BUILD MODE, then hit CLEAR PLOT to wipe the grid. The inventory opens with the VEHICLE and WEAPONS tabs. Keep the placement controls in mind throughout: click to place, R to rotate, T to tilt, and X to cancel.

Entering Build Mode with the parts inventory open and the Clear Plot button ready to wipe the grid. Shown at 00:46 in Kraken Captain’s video. Image: Zombie Car Crusher

Build the front wheel and nose

Place the Cloudrunner Wheel on the build grid. This is the steering wheel at the front of the bike.

Set a Carbon Fiber Slab directly in front of the wheel to act as the base of the nose.

Front Wheel & Base Slab Placement — The front wheel in position with the base slab laid out ahead of it. Shown at 01:06 in Kraken Captain’s video. Image: Zombie Car Crusher

Angle a Carbon Fiber Wedge across the front wheel’s upper arc, with its nose pointing downward. That tilt forms the bike’s slanted front.

Build the main body spine

Attach a Carbon Fiber Block behind the slab, then a second block behind that, running the line along the spine of the bike. Add one more block directly beneath the first one so the frame has depth.

Front Wedge & Main Body Blocks — The carbon fiber blocks lined up along the spine form the core of the body. Shown at 01:19 in Kraken Captain’s video. Image: Zombie Car Crusher

Fasten a Double Wing below the second carbon fiber block, leaving the hollow beneath the frame where the turbo will later sit.

Add the headlight, handlebars, and fairing

Place a Headlight block at the top front of the build.

Take two Pro Wings and rotate them outward to each side of the front wedge. These stand in as the handlebars.

Front Headlight & Handlebars — The headlight and two Pro Wings turned outward give the bike its handlebars. Shown at 01:52 in Kraken Captain’s video. Image: Zombie Car Crusher

Place a Hood Scoop atop the block just behind the headlight. Its slanting surface bridges the gap and forms a fairing.

Mount the turbo, seat, fuel, and engine

Insert a Rocket Turbo inside the Double Wing under-frame you built earlier.

Place a Driver Seat above the lower section. Tilt it flat for a low, laying-down riding pose, or leave it upright. Both work, so pick the look you want.

Rocket Turbo & Driver Seat Setup — The Rocket Turbo tucked into the under-frame with the angled Driver Seat on top. Shown at 02:44 in Kraken Captain’s video. Image: Zombie Car Crusher

Lay a Turbo Fuel cylinder horizontally behind the seat. This is also where the stabilizers attach at the end, so keep both sides of it clear.

Mount the Scarlet X engine behind the seat, above the frame. Flipping it upside-down keeps the styling clean without changing how it drives.

Fuel Tank & Scarlet X Turbo Engine — Selecting the Turbo Fuel tank and Scarlet X engine from the menu to finish the drivetrain. Shown at 03:30 in Kraken Captain’s video. Image: Zombie Car Crusher

Add the rear wheel and fender

Place the Titan Wheel directly behind the fuel tank to finish the inline, two-wheel layout.

Rest a Carbon Fiber Slab above the rear wheel, then angle a Carbon Fiber Wedge backward from it to form the rear fender.

Tuck a Twin Exhaust underneath the rear wedge. If you do not have one, a Carbon Fiber Slab fills the same spot.

Stop the motorcycle from flipping on turns

Drive the bike as it stands and it will roll over the instant you steer. Two inline wheels give the physics engine nothing to balance against sideways, so any lean becomes a full flip. The fix is to give it something low on each side to lean against.

Fit two Metal Spikes, one extending sideways from either side of the fuel tank, close to the ground. When the bike leans into a turn, the spike on the leaning side contacts the track, halting the tilt before the bike flips. Their low position keeps them from dragging on straightaways, so they function like hidden kickstands. Armored Cylinders or small spoilers can serve the same purpose.

Test drive and confirm it works

Use F to start, or click the green DRIVE button, then guide the bike along the zombie track. The stabilizers are working if you can steer sharply through a zombie crowd and the bike tilts without toppling. With the Scarlet X engine, a clean build can exceed 130 studs per second and remain upright.

Both seat setups hold up at that speed. The flat, laying-down seat keeps the center of mass low, while the upright seat changes the pose without hurting the handling. Once it drives straight and turns without rolling, the build is finished and ready to mow through the horde.