How to make the 2022 KTM RC390 transmission better?

[morgans1980]

Hey Paxton and community,

I've been bringing my 2022 RC390 to the track exclusively since last year. I've noticed that the QS both up and down are just terribly unreliable. I've installed the shift shaft support, but that hasn't helped the situation. Here are my main issues:

1. Upshifts are very inconsistent. I notice it the most between 3rd and 4th and it just won't upshift and then I hit the limiter.
2. Downshifts from 4th to 3rd are also the same problem, but even worse, because I've had multiple instances where it will go to 3rd, but then bounce back up to 4th! I've had this happen in 5th to 4th too.
3. Neutral is non-existent. I've owned a Ducati, and I thought that was bad. This is even worse.

Is there anything I can do about this? I have the RapidBike Race and thinking about getting the QS unit. Would that help? Would upgrading the slipper clutch make a difference? I see there's an STM EVO unit, but I'm not sure that will solve my issue. Any help would be great!

-Morgan

 

[pineappleguru]

I share your frustrations. I don't have the QS, but I manually clutchless upshift so I preload the shifter with my left foot and quickly roll of and back on the gas. This is basically what the quickshifter is doing automatically for upshifting at least. I've missed gear and hit redline once and then it jumped into gear (like how you described). But my main problem is that it's pretty inconsistent. Sometimes it's buttery smooth and sometimes there's a jerk as the bike slips into gear. I'd be interested to know if anyone in the community knows of any gearbox mods to fix this because I don't think it's a problem with the QS system per se but more of how the gearbox handles shifts without the clutch.

 

[Superpacman13]

The true solution is to undercut the transmission, but we band aided it with the best quickshifter I could get (HM) and then shimmed the transmission for better engagement.

 

[pineappleguru]

The true solution is to undercut the transmission, but we band aided it with the best quickshifter I could get (HM) and then shimmed the transmission for better engagement.

Interesting. Curious, is this just poorly engineered on KTM's part, or is there something else affecting the gears interconnecting? Also, is the gearbox for the 2022 models different from the previous gen, and if so is this a known issue on those bikes as well?

 

[Superpacman13]

Its not new but worse on the 22's from what I can tell. I would attribute this change to a decline in build quality.

 

[pineappleguru]

Do you think it's due to the additional power or some new componentry elsewhere? Asking because if so it would be smart not to further increase the power...

 

[Superpacman13]

No as stated before I think it is just a decline in build quality and adherences to their own tolerances.