Roads in Southeast Asia have been getting a little louder lately as motorcycle makers, an aspiring middle class and easy bank credit come together to breed a new genus of motorcyclists – the big-bike rider. Traffic in urban centers such as Jakarta, Kuala Lumpur and Ho Chi Minh City has long been characterized by swarms of small motorbikes and scooters. Honda Motor and Yamaha Motor (7272.T), the world’s biggest motorbike makers, have dominated this sprawling regional market.