[beatr911]

Those 135 Citroen tires are only an inch and a half wider than a typical 100 width M/C tire. Heck a 155 section tire is only about 2 inches wider than the same M/C tire.

That being said, 100 width m/c tires made for touring, pumped up to 50 psi would provide a pretty darn narrow contact patch. Probably pretty low friction with the right tire choice. Tire longevity would be less than the car tires, but that's not the point.

For lowest steering effort go with thin small diameter tires and the lowesT vehicle weight possible. The longer contact patch of m/c tires acts like a rudder trying to keep the tire straight. Make sure the steering and suspension attachment points are very rigid. Body flex is a contributor to heavy, vague steering. Little 145x12" Metro doughnuts will do a fine job for what you're after.