What's the max tire width ?

eBullitt, eBullitt X:

• Rear: 26” x 1.75"
• Front 20” x 1.75"

Original Bullitt, Bullitt X:

• Rear: 26” x 1.75"
• Front 20” x 1.75"

This will give a tire clearance of at least ≥6mm when tire is inflated to Schwalbe's recommended pressure.

Actual tire width is subject to vary depending on thread/knobs, inner rim width, tire pressure and stretching over time.
You may be able to squeeze a wider tyre in but it’s not something we recommend as you won't have proper clearance for dirt and wheel flex.
If you can fit an M6 bolt in between tire and frame/fork/fenders, you got enough clearance.