
Bajaj Auto and Triumph Motorcycles duo are working on a new 350cc 400 class motorcycle. This upcoming motorcycle, called Bonneville 400, will be manufactured by Bajaj Auto at its Pune facility and has been spotted testing several times. Its direct competition will be with Royal Enfield Classic 350 and Honda CB350.
The latest spy shots reveal that the test model looks like it is ready for production and may undergo the final stages of testing before its grand launch. With distinctive bicycle parts and design language, the upcoming Triumph Bonneville 400 could be the most ‘classic’ motorcycle format from the brand.
Triumph Bonneville 400 spied
350cc Retro Classic Motorcycle Buyers generally make purchasing decisions based on their heart, not their head. Desirability plays a key role here and the upcoming Triumph Bonneville 400 aims to address this. For starters, it doesn’t look much like the Speed 400 or the Speed T4, which can be said to be more of a neo retro than a classic.

The design of the Bonneville 400 is classic and its proportions also feel classic. So, the upcoming Bonneville 400 Speed may be slightly larger than the 400 Duo. A wide teardrop fuel tank, wide classic-style handlebar, wide and well-padded seat, bench-like seating arrangement, a straight pea-shooter single-sided exhaust and other elements are expected.
An all-new rear subframe for the Bonnie is flat compared to the Speed and is then suspended on a twin-shock rear suspension setup. A simple swingarm is also expected. Other notable bicycle parts include an RSU telescopic front fork setup with fork gaiters and wire-spoke alloy wheels, which appear to be finished in black.
what to expect?
The classic style front and rear fenders with circular LED headlights establish its retro and classic design aesthetics. These headlights will be LED and may be shared with other Triumph 400s in the portfolio. The turn indicators are also circular and may be LED, while the LED tail light looks like it is an oval-shaped unit.

A circular instrument cluster can be seen in previous spy shots and is unique to the Bonnie. We hope it’s a fully analog unit to match the retro aesthetics of this motorcycle. Previous spy shots have confirmed that there could be multiple variants of this machine and the top variant could come with a chrome exhaust, chrome engine casing, chrome grab rail and more.
The same 350cc single-cylinder liquid-cooled engine will power other Triumph 400s. It is not yet confirmed whether the engine tune will be the same as the Speed T4, Speed 400 or Thruxton 400. The launch is expected to take place in the second half of 2026.