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Hi

recently the bike judder excessively during very low rpm, ie: below 2000 rpm.
very noticeable during heavy traffic.

just noticed how bad the judder when I put it on the race stand, put it on 1st gear and let the wheel run, it judder like crazy, but soon you open the throttle the judder gone.

I have replace the clutch pack, friction and the steel plate, but still exists.
I have done the reset adaptation as well.

Anyone know what caused this?

Many thanks
 

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MacBandit offers a sensible stab at what it might be and, having already made your mind up, you dismiss it without even a thank you. C'mon, you're better than that.

:frown2:
 

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There is such a thing as running an engine at too low an rpm. The Street Triple engine is happiest above 4000 rpm, and accelerating below 3000 rpm will definitely cause a transitory shudder or vibration which is normal. This is a high revving engine and does not like putting around town.
 

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If it would pull smoothly under 2000rpm previously then it has to be something has definitely changed.

Try running the chain just a little looser. And check the countershaft sprocket nut is still tight.

Has it been in the dealers recently? Could they have loaded a different map without telling you?
 

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If it only happens while riding when trying to accelerate from very low revs - 2000 is very low revs for this engine - I would say you are lugging the engine and that you absolutely need to change your habits to stop doing this. However, you say this:

...when I put it on the race stand, put it on 1st gear and let the wheel run, it judder like crazy, but soon you open the throttle the judder gone...
Which leads me to believe you are not lugging the engine. This is good, because besides running it without oil, lugging an engine is one of the worst things you can do.

Lugging an engine is like hammering the engine parts with every explosion in a cylinder. It racks on the rod bearing/journals, makes the pistons slap the side of the cylinders hard, and if is done enough, could probably break piston rings. It also creates a hammer effect all the way through the drivetrain. There are springs in the friction disk (of the clutch) which takes up some of this hammering, but they will only take so much before they wear out as well. This causes premature wear all the way around. It's not like it will wear out tomorrow, but it will cause wear over time. If you want your car to last a while, you don't want to be doing this.
If your "judder" only happens at very low speeds in gear with the rear wheel spinning - like when you had it on the stand - then MacBandit is probably correct (good odds of that since he is an actual bike mechanic), and the judder is due to your chain, and or sprockets. If it happens at similar revs in neutral, without the chain and wheel spinning, then it's probably engine related.
 

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Keep in mind even a new bike ran on a stand will have the rear wheel judder and bounce. This is because there is no load on it to even put the engine pulses and chain slop.
Good point.
 

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Keep in mind even a new bike ran on a stand will have the rear wheel judder and bounce. This is because there is no load on it to even put the engine pulses and chain slop.
I think the OP is saying it happens when he's in traffic, too.

My bike ran a little rough at idle until and I used to think it went away while riding but if i held the throttle steady in motion, I noticed it still persisted. I did a throttle body synch and it helped significantly. You should look into it. It's a maintenance item.

Sent from my Pixel 3 using Tapatalk
 

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Understood. I’m just explain why he was experiencing it on a stand. There are literally hundreds of potential causes. That is why I haven’t gone further. The first real step is to go to a dealer and let someone else ride it to verify the issue is actually real and not something the rider has found a way to cause by accident.
 
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