All-Japan Dirt Trial Round 4 Sunagawa — Class Winners Confirmed, Next Stop Ebisu

Sunagawa is one of Hokkaido's premier dirt trial venues, known for its combination of flat, high-speed sections and technically demanding corners. Conditions were stable on race weekend, and fast times were recorded across all classes.

In the top-tier D2 class, Tanigawa Toshiyuki took victory with a time of 1'22.011. D1 class honours went to Otani Yukimasa at 1'32.942. The SC class was won by Okamoto Taisei (1'22.958), SA2 by Kasahara Riku (1'23.838), SA1 by Fukushima Kendaro (1'30.989), and the N class by Hosoki Tomoya with a time of 1'24.580.

The Hokkaido round carries particular weight in the championship calendar. Local drivers know every nuance of the surface and pressed their home advantage against competitors who had travelled from across Japan. Tyre selection and stage management proved decisive throughout the day.

Round 5 takes place at Ebisu Circuit's new south course on July 18–19. Ebisu's undulating, complex layout demands a completely different setup and driving approach from Sunagawa, making it a pivotal round as the second half of the season approaches.

A closer look at the timing data shows that D2 class winner Tanigawa's margin at 1'22.011 was a little over 0.8 seconds ahead of second place — a small gap by road racing standards, but substantial in the world of dirt trial where a single run determines the result. Tyre selection and ride height adjustments proved critical in a high-speed environment where tenths of a second separate championship positions. The fact that SA2 class winner Kasahara and SC winner Okamoto both recorded times in the 1'23 bracket — different classes, different machinery regulations — reflects how closely matched the technical standards of the two categories have become.