The additional weight, power, and torque will be no problem for any vintage bike. Guaranteed to work every time. You won't have any problems. Since that old Raleigh is so redundantly reliable it will just soldier on when it has a new and much larger engine. Bicycle tires will be fine. Bicycle brakes will be fine. No learning curve involved at all. Your reflexes and habits will cause no issues when you suddenly have three times the power. Enjoy your new motorcycle.