Restomod Thumper: Yamaha SR400 by DOTi Motorcycle

Yamaha SR400 Motard

JDM Motard: A big single streetbike from Vietnam…

The Yamaha SR400 has been available in the Japanese Domestic Market (JDM) since 1978, originally developed as a street-oriented spinoff of the legendary XT500 enduro. To comply with Japan’s licensing requirements, the displacement was reduced to 399cc via a different crank, giving the shorter-stroke engine a more “revvy” character. Sticking to its minimalist roots, the SR never incorporated an electric start, though it did become fuel-injected in 2010.

Yamaha SR400 Motard

Over the years, this single-cylinder street thumper has developed something of a cult following:

“Unlike some retro bikes that are modern interpretations of older designs, the SR400 is an authentic living classic which has been constructed to virtually the same specification as the original model. With its air-cooled engine and twin-shock chassis, this timeless big single represents a return to motorcycling’s core values.”

Yamaha SR400 Motard

Unfortunately, Yamaha has announced that 2021 will be the last year of production for the SR400 — the end of an era. Fortunately, there are still plenty of these bikes on the used market, and mechanics/customizers like our new friend Nguyen Dinh Trung (@doti.ndt) of Vietnam’s DOTi Motorcycle are keeping these bikes alive and evolving.

Yamaha SR400 Motard

Nguyen grew up in a small town in Vietnam and has dreamed of customizing bikes since middle school. In college, he got into the business of making and selling motorcycle accessories, starting with just $100 to his name. About a year ago, he opened his garage, DOTi Motorcycle, and we recently featured one of his SR400 builds — a high-spec thumper that we absolutely loved:

“We love that it doesn’t follow any specific genre or style — it’s more of a high-spec roadster that retains the general silhouette of the original, yet little of the OEM machine remains.”

Yamaha SR400 Motard

Now Nguyen is back with a 1992 SR400 motard built for the CEO of Vietnam’s Raw Helmets, who wanted a unique bike for his daily commute. Says Nguyen:

“The design concept followed the general tracker / supermoto style with some modifications to make this SR400 cleaner, fresher, and more comfortable, and to make the owner enjoy it better.”

Yamaha SR400 Motard

Since the owner is a big fan of the bike’s single-cylinder power, Nguyen decided it would be a good idea to upgrade the brakes, utilizing Nissin four-piston calipers up front and Tokicos in the rear, and the original spoked wheels have been swapped for sweet set of Honda NSR250 mags. The bike is now sporting a set of YSS rear shocks, four-level adjustable forks (soft to hard), and a Danmoto titanium exhaust system.

Yamaha SR400 Motard

The result is a more comfortable, more performance-oriented SR400 motard that retains the classic lines — with a modern touch.

Yamaha SR400 Supermoto: Builder Interview

Yamaha SR400 Motard

• What’s the make, model, and year of the bike?

This bike is the Yamaha SR400 manufactured in Japan for the Japanese Domestic Market, model year 1992.

Yamaha SR400 Motard

• Why was this bike built?

I built this bike as a customer project. My customer is the CEO of the Raw Helmets brand here in Vietnam.

Yamaha SR400 Motard

• What was the design concept and what influenced the build?

The owner wanted something different from the original SR, but he also needed a comfortable riding position for his daily commute. The design concept followed the general tracker / supermoto style with some modifications to make this SR400 cleaner, fresher, and more comfortable, and to make the owner enjoy it better.

Yamaha SR400 Motard

• What custom work was done to the bike?

The owner loves the power of the SR400 engine. I thought the brake system needed to be better than the original, so I used Nissin four-piston calipers at the front wheel and Tokico calipers at the back.

I also swapped out the rear suspension for YSS shocks that are longer than the originals. The exhaust was also replaced with a titanium system from Danmoto.

• Does the bike have a nickname?

No, it’s don’t have a nickname.

• Can you tell us what it’s like to ride this bike?

When riding this bike, the first thing I feel is the comfortable, commanding riding position, which comes from the higher handlebar. Moreover, the powerful sound of the exhaust is so exciting — it made me want to ride as much as I could.

Yamaha SR400 Motard

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Instagram: @doti.motorcycle
Instagram: @doti.ndt


  1. I absolutely love SR’s, and this one is no exception! I wonder how hard it would be to import an older SR like this to the US, as they’re pretty rare here.

  2. How can I get my hands on one.

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