Does a gear change require a shift point change?

[rossb]

Do I need to adjust the transmission shift point if I install the 18T clutch bell?

What determines the shift point? Is it based on spur gear RPM or output shaft RPM?

 

[GilBeQuick]

IMO you shouldn't have to adjust your shift point if you've already got it set they way it should be. It depends on how you gear it. If you gear it for higher top speed then you may want to shift later so when you do shift your rpms don't fall low enough that it struggles to accellerate in second gear. If you set it to shift later it'll be in a slightly higher rpm when it shifts and won't struggle as bad to accellerate.

I would say it really depends on your engine's powerband more than anything. If it's a high revving, strong top end engine you don't want it to shift early on because you'd be wasting the engine's powerband. If it's a down low torquey engine you don't want to shift to late because again you'd be wasting your engine's powerband.

If you have your shift point adjusted right, you should barely be able to hear your engine shift. It'll just be very smooth accelleration from the start all the way up.

 

[rossb]

Is the shift point based on output shaft RPM (road speed)? If so then installing a taller gear set (18T bell) would cause the transmission to shift at a lower RPM because the gearing change is made at the transmission input side.

 

[UNCDROCK57]

Yeah, when I changed from a 14t Cb to a 16T Cb I had to change the shift point because with the 16T it would shift way to early. So in my experience you do have to change the shift point. Lower tooth CB, the more RPMs the motor will produce before it changes. A higher tooth CB, the motor will produce lesser RPMs before it shifts, which will be earlier.