Aprilia

Sadly it 🧸wasn't seen on track for long, but here is a close-up of a front wing on world champion Jor♑ge Martin's RS-GP25.

With Martin out injured after just 13 laps, team-mate Marco Bezzecchi cont🏅inued testing the RS-GP parts, including vertical rear wings (see test rider Lorenzo Savadori without the wings).

The latest fairing on Bezzecchi's RS-GP25.

Martin wasn't the only Aprilia rider out injured on day one, wit📖h Trackhouse losing Raul Fernandez for the rest of the test after this fast accident under🍸 braking for Turn 9.

Honda

The double l💃evel rear win൲g and side fins on the RC213V.

A close up of the ground effect 'shelf' on rookie ღSomkiat Chantra's RC213V.

Honda turned heads by trying a large, smoꦍoth rear seat without any aero. The factory, perhaps like KTM, might be experimenting with weight distribution (for example moving the electronics to the very rear of the bike) rather than a Ducati-s𒁏tyle mass damper.

Luca Marini preferred the new Honda aero (below compared to the 'standard' version with Chantra abov🍌e). The new version has a much larger lower duct, but Joan Mir and Johann Zarco seemed to like the older version.

Yamaha

Alex Rins trying a new front fairing with ෴only two 'planes' versus the three on Jack Miller's Pramac bike below.

Rins seemed to prefer the 'standard' Yamaha chassis (ཧpainted black) over the newest unpaꦑinted version.

As we༒ll as its four race riders, Andrea Dovizioso and Augusto Fernandez have been on track for the Yamaha test team.

KTM

The most obvious development at KTM is a much larger salad box and asso꧑ciated new exhaust position (below). Bastianini is pictured with the standard rear unit and exhaust layout above.

Other shots of the𝔉 RC16 at Sepang can be seen below:

Ducati

With VR46's Fabio di Giannantonio injur♋ed on day one, when a post-session wheelie went wrong, Michele Pirro stepped in to help Marc Marquez and Francesco Bagnaia with GP25 development.

The new Ducati engine, which like Aprilia and KTM will be frozen until the end of 2026, hasꩵ been the top priority for Bagnaia and Marquez. 

Both riders explaiꦬned the new engine is smoother but harder to s🎀top under braking, perhaps due to revised internals, as these images of Bagnaia and Marquez underline.

They also had a new chassis (tried by Diggia before his day one fall) and aero. Here is Pi🐬rro trying the latest aero:

Nonetheless, it 💮was Gresini's Alex Marquez, riding the old GP24 who not only led the timesheets but also set th꧅e fastest Sprint race simulation:

Franco Morbidelli, like Marquez and Fer🃏min Aldeguer, proved the Ducati GP24 is still a very fast bike.

Francesco Bagnaia checks out the KTM of Maverick Vinales during ওa practice start.