Sprint 18 Teeth Sprocket - Any Though?

Hi, I was wondering why I had almost 10 km/h gap between real speed and the speedometer.
Just checked.. I have a 18 teeth sprocket instead of the 19 teeth.

Should I come back to a 19 teeth on the next chain change?
Does it make a big difference?

It's a Sprint 1050

 

The issue is I can't compare. I would be tempted to put back a 19, but as we often ride 2 + luggages on the bike, I'm wondering of the 18 is not better.
If I stay on the 18 I will adjust the speedometer with tuneecu.

 

Yes you are probably right. I have way enough juice, the bike push really hard , not sure an extra tooth will make the bike boring.
In France we ride long distance at a stabilized 130 km/h speed. A few rev less will be welcome.

The other solution would be to apply a fix to the speed reloading a map in the ecu. Not keen doing that.

Thank you for all people there for your input

 

Just ordered a 19 t sprocket.. 20 bucks.. I will be able to compare and put the one I like.

 

I quikly made an excel sheet to calculate differences.
18 teeth sprocket at 4800 tr/m:


Same with 19 teeth sprocket


I hope I didn't outdid the calculation, but looks like it's realistic.

If someone wants to play with my excel sheet pm you email, I'll send it.
Just gonna add the perimeter calculation from tire indication.

 

Received the 19t sprocket.
It's now on the bike. Despite a new 4 weeks lockdown starting and a 10 km restriction, I made 2 rides to compare. One alone, one with Madame.
I will keep that 19t instead of the 18t. It's smoother, imho better adapted to the engine torque curve.
The bike still have enough power to catapult me in a few seconds.