Triumphrat

wakx

I have a new 2012 Bonnie Black with barely 300 miles to it, still in the break-in period.

Sometimes whenever I go into 1st from neutral, there is a very loud CLUNK sound. And then sometimes there is no sound at all, a very easy transition.

I blip when I upshift and downshift. Not really riding it very hard.

I also sometimes hear it with other motorcycles on the road. I seem to remember a similar phenomenon with my first bike, a Honda Nighthawk CB250.

Can anyone explain to me (a not-very-mechanically-inclined noob) what is happening in the bike for it to happen just sometimes?

arbeach

What I have been told long ago is that when not engaged your drive is not spinning or slowing. So when you engage with a spinning gear you can get a clunk or a grinding. Preloading your shifts helps quicker shifting which will take care of the 1-2-3. Neutral to first the motor should be at idle. I normally recommend staying in gear at lights and traffic (Its a safety thing). I'm sure there is someone on here who completely disagrees with me and I'm A-OK with that.

Junipero

You'll also find that as your Bonnie breaks in, the tranny gets much much smoother. The transmissions on the Bonnies are fantastic. At 25K on my Bonnie, it's like butter. My RT on the other hand is like shifting a tractor.

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NORTY FLATZ

Hard to explain in layman's terms. It has to do with the clutch pack not fully releasing. There are lots of reasons why it may (or may not) fully release. Oil temp, previous plate separation, oil viscosity, oil additive packages components. Shift fork dog fitment in shift drum.

The easiest way to minimize it is to "pause" after you pull the clutch lever in for 1~2 seconds, THEN apply pressure to the shifter pedal. (From N to 1st.) Try it and see if it helps.

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wakx

Yeah, all of the above and everything arbeach wrote is all Greek to me. I have a very basic understanding of how a motor works and how the power is transferred to the wheels. But once you get any deeper than that, I'm lost. I do appreciate the suggestion and I will indeed try it and report back.

Thanks!

DeanRider

While '02 Daytona 955i gearbox is as smooth as butter, my son's '06 Honda Fireblade also 'cluncks' into first gear even though is seamless between gears. I have found this to be the case with a number of other Japanese Superbikes I have ridden over the past years. Nothing too mysterious and not a big deal really...

williamr

A clunk going from neutral to first is common on most bikes as the clutch plates stick together a bit because of the oil. It's worse when the engine is cold. Put it into gear and the transmission starts to pull, then the loading hitting the clutch causes the plates to fully separate and release. The clunk is the slack in the chain and gears taking up.

Rob

NORTY FLATZ

Partially, but mostly within the clutch basket.

Let's see if we can get this by the mods~

The chain slack and gear clearances is called "driveline s natch" Most noticable in vehicles with a differential.

I'm not sure this will get through but that's what it's really called.

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KitNYC

Please be aware that it's not the mods; it's an auto-censor with a dictionary that we don't currently have control over.

Cheers,
-Kit

02bonneam

raise the back wheel and put your foot on the back break, if the rear wheel moves you need a new rubber dampener in the rear hub, that clunck was what i got after i'd been to the drag races easy fixed.