If there’s one thing that’s true about major motorcycle manufacturers in general, it’s that any new engine design that it’s taken time to painstakingly develop is going to go in more than one machine. While rumors and spy photos of what appears to be the upcoming KTM RC 990 have appeared in the past, this most recent batch shows street testing of a prototype in Europe.  

It’s powered by the same heavily modified LC8c engine as should power the KTM 990 Duke Prototype that was also recently spotted testing in Europe. It’s also expected to use the same chassis underneath that fairing.  

While the images of the 990 Duke Prototype were almost all taken from the left side of the bike, these images of the RC 990 instead spend a great deal of time on the right side of the bike. Still, comparing the two sets of spy photos reveals not only the same swingarm, but also what appears to be the same exhaust canister that ends in a sort of rounded-square shape just before the tip.  

Gallery: 2025 KTM RC 990 Prototype Spy Photos

By their very nature, of course, the 990 Duke Prototype and the RC 990 are completely different in appearance. The fairings on the RC 990 clearly hark back to some of KTM’s previous fully faired sport successes, from the RC8 and RC8 C to Team Orange’s RC16 MotoGP machine. As you’d expect, the riding position is also significantly more aggressive than the one found on the 990 Duke Prototype. 

Rumblings about other developments on the RC 990 include an expectation of engine power figures topping 140 horsepower, with torque as yet unspecified. While previous prototypes of the RC 990 more clearly showed Brembo Stylema calipers, the ones here are lightly disguised. It’s unclear what kind of developments may be in store in that department, but expectations of strong performance remain high, as ever. Still, as usual, we should caution that everything is very much speculation at this point.

The headlight is also somewhat disguised on this RC 990 prototype; much more so than it appeared to be on the 990 Duke prototype. Although this test mule appears to be further along in development than some of the images spotted in 2022, current expectation is that we probably shouldn’t expect to see a production RC 990 until sometime in 2025. Still, it’s almost August 2023—which puts us that much closer to the start of 2024.

Got a tip for us? Email: tips@rideapart.com