Two contact patches. Choose them well.

Learner-approved bikes sit around 150–200 kW per tonne of wet weight, about the same as a hot hatch. Middleweights like the Yamaha MT-07 are near 300 kW/t, and litre superbikes pass 700 kW/t, roughly double a supercar. What's right depends on experience: most riders are quicker and safer on a bike they can use fully.

For comparing bikes, no: manufacturers quote weight without a rider, so ratio does the same. For how the bike actually feels, yes, because a 75 kg rider adds a third or more to a bike's weight. Switch on 'Add a rider' to see it; LAMS uses its own allowance of 90 kg for rider and fuel.

Wet weight: ready to ride with a full tank of fuel and all fluids. Dry weights leave out fuel, oil and sometimes the battery, and can be 15–25 kg lighter. If you only have a dry weight, add the tank's capacity in litres times 0.74 kg, plus a few kilograms for oil and coolant.

It sets the floor. A powerful bike needs radial construction and a speed rating to match, and a hyperbike shouldn't run commuter rubber. Within that, how you ride and where you live matter more on a bike than in a car: wet grip and warm-up time are what keep riders upright.