I have a spreadsheet that auto calcs mph with the different gearing and tires. I have the 16-18, 19 and 19 gytr reduction ratios. Pretty sure the TW 30% is the same as the '19 GYTR kit. Not sure how to upload it.yamaha torque assist vs 2019 reduction in 1st gear is a difference of 2.4:1 for 2019 from 2.06:1 2016 and 2.62 for the yamaha torque assist gears now just calculating the middle gears to see the difference but need numbers. this is just the 1st gear calculations not total.