Segway PT x2 Reference Manual page 27

Figure 4. How Segway PT Works - Turning
The Segway PT's dynamic stabilization technology balances forward
and backward but not side-to-side. If you tip the Segway PT onto one
Wheel, it will not dynamically bring itself underneath you and it could
fall over. You are responsible for maintaining side-to-side stability
while riding the Segway PT. To do this, keep your body aligned with
the LeanSteer Frame. Lean into turns and lean uphill when riding
across a slope to maintain side-to-side balance.
When riding across a slope with one Wheel higher than the other,
keep the LeanSteer Frame vertical to keep from turning.
NOTE:
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