TOKYO -- Many Japanese motorcycle models are being retired as the industry's big names adjust to tighter safety and environmental regulations as well shrinking popularity.

Japan's motorcycle market is now 11% of what it was at its peak, with annual sales totaling 370,000 units.

Starting in September, makers will be required to halve the emissions of existing models with engine displacements of over 50cc.

The requirement will bring the domestic environmental regulations in line with the EU's old Euro 4 standards. The government is mulling further tightening the regulations in 2020 or later.

Further adding to manufacturers' costs, the government in 2018 plans to require motorcycles to have anti-lock brakes.

Honda Motor, the top maker, with a market share of over 40%, has made 24 of its 74 models compatible with the incoming environmental and safety requirements. Of the remaining models, the Super Cub small bike and the 1800cc Goldwing are being killed off for now; they are to be reintroduced after they can be made regulation-compliant.

But even models not subject to the new requirements -- like the Monkey and Little Cub, whose engine displacements are below 50cc -- are being dropped from production.

For makers, recovering development costs or cutting costs on relatively cheaper models is difficult.

No. 2 Yamaha Motor plans to dead-end 15 of its 47 existing models, including the Drag Star cruiser and the long-selling SR400 -- although the SR400 and two other models will be reintroduced after their environmental performances are brought up to standard.

Suzuki Motor has made 11 of its models compatible with the new regulations and plans to do the same for its 29 other models. Kawasaki Heavy Industries plans to terminate the Estrella, a sports bike with a classic appearance, and four other models. Six of its 19 models comply with the new standards.

(Nikkei)