Right my bike has 16/45 gearing that the previous owner put on. Thinking about switching the gearing to 15/42. Would it be much of a difference? Or would it be pretty similar to what's on the bike now?
So theoretically your front sprocket will turn by 0.0125 turns less for each rear sprocket's full rotation. That means it'll be a bit "longer" geared than with the 16/45.
Probably a couple of mph more on the same rpms
I don't think that you'll notice much on the throttle while riding it though
You'd achieve a tad more power at the rear wheel, since a 15T sprocket is easier for your motor to turn than a 16T, but I'm not sure you'd notice it. I'm not smart enough to convert it to torque figures.
Only variable IS torque.
Power will stay the same.
Can't work out power without a torque figure to start with.
Power = torque X rpm
Smaller drive sprocket = more torque + less rpm = same power