Wider tires are often more stable than narrow tires.


More trail tends to make a bike more stable.


A low bottom bracket will lower the center of gravity and contribute to a more stable bike.


All these factors interact with the others. It is possible to make a bike too stable. In that case it might be hard to correct the line if you have to avoid a pothole or another bike.


Also after years of riding one bike; it takes time to adapt to a new bike, and its handling characteristics.