View Full Version : Quickshifter Question - Loud Pop/Bang Sound

01-15-2019, 01:23 PM
Hi guys,

Name is Ken and I live in Sydney, Australia. Glad to be in this forum and nice to meet all of you. Recently picked up a 2012 RSV4 APRC model I am so happy to be owning this beast and have been enjoying it for the past couple of weeks. Now straight to the problem (I'm not too sure if it is). I was riding back home and came to a complete stop at a set of lights. I took off and and used the QS at around 9-10k RPM and as I soon as I kicked it up, I heard a loud crack/bang noise (obviously not the exhaust) and the REV suddenly climbed up to between 13-14k RPM and the back wheel started spinning. I donít think it was in second gear and I couldnít remember properly because that noise freaked me out and the rider who took off behind me heard it as well (he followed from behind). I quickly pulled in the clutch and slowly pulled to the side to have a look at the bike because of the noise. The bike looked cosmetically fine and the gearbox, chains, etc looked fine. I got back onto the bike and slowly rode it back home with all the gears engaging properly (using both the clutch and QS).

I know that I might have not kicked up hard enough to engage to the next gear but was the previous noise normal? I took the bike out after that because I was so paranoid and done the exact same thing (used the QS between 9-10K RPM from 1st to 2nd gear a couple of times) and everything was fine.

Sorry if this experience was addressed earlier but it would be nice if someone can shed some lights.

Lazy QS shift? but how about that loud noise?(sounded like my chains was about to come off).


01-15-2019, 05:43 PM
Kinda hard to diagnose but it sounds like you simply missed a gear.

- Revs jumped up suddenly indicating that the engine was not restricted by the speed of the rear wheel - ie false neutral.
- Rear wheel started ‘spinning’. Sounds like you suddenly lost drive which would have felt like it was spinning when it most likely would be very much ok (it’s almost impossible to spin the wheel when moving at speed, it’s exceptionally difficult to break straight line traction unless you are trying to do it.)

Then bang I can only speculate on. It’s possible you broke a component in the gearbox but it’s also likely that was the mechanical sound of you missing a gear. I’ve done it a few lines in the track and it’s audible.

This is all speculation from me of course.

01-15-2019, 07:29 PM
Hi Das. Thank you for your input. The first 2 points makes sense. In regards to the "bang", if there is a component that that has been damaged or broken in the gearbox, wouldn't that prevent me from riding the bike or have issues when operating the gearbox/clutch? Sorry for being a total newb and I am super paranoid that I am hearing this "noise" from the miss-shift/lazy-shift and having recently owned the bike. I spoke with the previous owner and he has said that he had no issues with the bike and this is the first time he had come across it.