Somkiat Chantra Returns to MotoGP as Mir’s Motegi Replacement

Somkiat Chantra is heading back to MotoGP. Honda Racing Corporation confirmed on 23 September that the Thai rider will replace Joan Mir in the Honda HRC Castrol team at the Japanese Grand Prix at Motegi, as the 2020 world champion continues his recovery from the health problems that have kept him off the bike since the San Marino Grand Prix.

Chantra, who raced in the premier class for Honda LCR in 2025, has spent the 2026 season in HRC’s World Superbike programme. The call-up gives him a factory RC213V for the weekend of 2 to 4 October and a return to a circuit that holds special meaning in his career.

The key facts

• Chantra replaces Joan Mir at Honda HRC Castrol for the Japanese Grand Prix.
• He raced in MotoGP with Honda LCR in 2025.
• In 2026 he has competed in WorldSBK with HRC, scoring points seven times.
• He won a Moto2 race at Motegi in 2023 and finished 15th there in MotoGP in 2025.
• Mir’s condition will be updated after the Indonesian Grand Prix.

Why Motegi matters to Chantra

Chantra’s Moto2 victory at Motegi in 2023 was one of the defining moments of his rise through the intermediate class and helped earn him the chance to become Thailand’s first MotoGP rider. When he returned to the Japanese circuit as a rookie on the Honda RC213V in 2025, he finished 15th, a modest but solid result in a difficult season for Honda’s satellite team.

The circuit suits a rider who knows where to brake. Motegi is a stop-and-go layout with some of the hardest braking zones on the calendar, and familiarity with its reference points can help a stand-in rider settle faster. Chantra’s previous experience there should reduce the learning curve at a time when he will have limited track time to adapt from a Superbike back to a prototype.

A season of recovery in WorldSBK

Chantra’s move to World Superbike for 2026 was a significant change of direction. MotoGP.com notes that his campaign has been affected by pre-season injuries, which he has had to recover from while racing. Even so, he has scored points on seven occasions, showing steady progress on the Honda Fireblade.

Switching from a production-based Superbike to a MotoGP machine is not straightforward. The prototype has more power, more sophisticated aerodynamics and electronics, and a different tyre supplier this season, with MotoGP using Michelin while WorldSBK uses Pirelli. Chantra will need to readjust his braking, corner entry and throttle application within the limited sessions of a Grand Prix weekend.

• More power and aerodynamic load than a Superbike.
• Michelin tyres in MotoGP this season compared with Pirelli in WorldSBK.
• Different electronics strategy and riding position.
• Limited practice time before qualifying and the Sprint.

Why Honda chose him

Honda had several options. Crash.net had listed test rider Takaaki Nakagami, who stood in for Mir in Austria, as well as Aleix Espargaro and Cal Crutchlow among the possibilities. Nakagami was already scheduled to ride at Motegi as a wildcard, which may have influenced the decision to look elsewhere for Mir’s seat.

Choosing Chantra keeps the seat within the HRC family and gives Honda a rider who knows the RC213V from a full season of racing. It also rewards a rider the company has supported through the ranks. For HRC, the priority is consistent feedback and clean laps rather than a headline result, and a rider with recent premier-class experience is better placed to provide that than someone stepping up for the first time.

The Southeast Asian angle

For fans across the region, including in Malaysia, Chantra’s return is a welcome story. Southeast Asia provides some of MotoGP’s most passionate audiences, from Buriram to Sepang and Mandalika, but riders from the region at the top level remain rare. Thailand’s first MotoGP rider appearing again on the premier-class grid, even as a replacement, keeps that representation visible.

Malaysian publication Paul Tan’s coverage highlighted the same point: Chantra carries the hopes of regional fans every time he appears in a MotoGP session. Whether he can make the most of this opportunity may also influence how Honda views him for future substitute roles or testing duties.

What to expect at Motegi

Expectations should be realistic. Chantra will be returning to the class mid-season, on a bike he has not raced in 2026, against riders fighting for a world championship. A points finish would represent a good weekend, and the main goal will be to build speed gradually, complete his programme without crashes and give Honda useful data.

It is worth remembering that he is not only filling a seat. Honda is in the middle of a demanding stretch of races while also preparing for the 850cc regulations, and every rider on the RC213V contributes information. A calm, consistent weekend would serve the team well.

Mir, meanwhile, remains in recovery. Honda said updates on his condition will follow after the Indonesian Grand Prix, meaning Chantra’s involvement beyond Motegi has not been confirmed in the announcement. For now, his focus will be on a single weekend at a track where he has already enjoyed one of the best moments of his career.

Measuring success

A fair way to judge Chantra’s weekend will be to compare him with his 2025 benchmark at the same track, when he finished 15th, and with the other Honda riders on similar machinery. Consistency across practice, the Sprint and the Grand Prix would be a strong outcome. Honda will also value clear technical feedback, because a rider arriving from another championship can sometimes spot characteristics that regulars have grown used to.

There is also a personal element. Chantra left MotoGP after one season and moved to WorldSBK to rebuild. A composed performance at Motegi would show that he remains a credible premier-class option, whether for future substitute rides, test work or a longer-term return.

His return will be one of the stories to watch in the paddock next week. Thailand has invested heavily in MotoGP through Buriram, and Chantra’s appearance on a factory Honda at Motegi gives the region another reason to follow the start of the Asian rounds closely.