CBR650F Gearbox backlash

[Shaun22P]

Hi everyone. I've had my CBR for a month now and put 780km on it. I have noticed however that there is a really annoying jerk in the handlebars when opening up and closing the throttle (and I mean a gradual opening and closing, not snapping it). It's small, but it makes you feel uncomfortable to push it.

I took it to the dealership several times and had the chain checked too, but my guess is that it is either backlash from the gearbox or something with the stearing head that creates this little loose back and forth jerk (even though they checked that too).

Has anyone experienced this or have any advice on the matter?

 

[Somchai]

My 2018 bike felt a little jerky too in the break-in period. I never felt any looseness or too much play though.

Probably engine braking is stronger at first, caused by the very tight initial fitting of the pistons in the cylinder.
It's better now for me (after about 1500 kms).
Overall the bike is very smooth. Initial vibrations in the clip-ons are almost completely eliminated too.

In slow traffic modulating the clutch can compensate jerkiness for the most part.

 

[Shaun22P]

My 2018 bike felt a little jerky too in the break-in period. I never felt any looseness or too much play though.

Probably engine braking is stronger at first, caused by the very tight initial fitting of the pistons in the cylinder.
It's better now for me (after about 1500 kms).
Overall the bike is very smooth. Initial vibrations in the clip-ons are almost completely eliminated too.

In slow traffic modulating the clutch can compensate jerkiness for the most part.

Perhaps you are right about the break-in period. It's fine during a slow ride, but once you need to overtake a car I can feel a tap in the handlebar, as if there was a slight shift somewhere in the front.

Thank you for the feedback. I'll see how it is after the first service.

 

[Brammers]

Check throttle cable free play... Adjust to minimum of 2mm. This helps a lot.

Grab the service manual and go for it.

J

 

[Somchai]

Check throttle cable free play... Adjust to minimum of 2mm. This helps a lot.

It is definitely a plausible reason, but I'd think that would be one of the first things the dealership would have checked.
I checked clutch, throttle and chain play for my bike at the 500 km mark and the clutch and throttle needed a tiny adjustment, chain still OK.
At the 1000 km service, the dealership adjusted all 3 again to the minimum allowed setting.
Cables and chains do keep on stretching. On my bicycle gears and brakes are cable operated, so I check those even more regular.

 

[Perza]

The first thing I did on my new 650f was adjust the throttle handle freeplay. It was about 6 or 7 mm which is just too much. Reduced that to practically zero and the response was completely different.

 

[Somchai]

Reduced that to practically zero and the response was completely different.

I like my throttle free play also as small as possible.
Important is to check that there's no throttle engagement when the front wheel is fully turned to the left and right.
A little buffer is however advisable. Even when you have a super stable throttle hand, a big road imperfection might force unintended throttle action.
That's also the reason dirt bikes need more free play.