Hi Tim here ,I have finished the first Izip upgrade and I an very pleased ! The bike came out very sturdy and is a blast to ride .The seat and seat post along with the seat post collar clamp have been changed as well as the handlebar stem. All of this stabilizes the top part of the bike for our needs. The tires have been changed and this helps quite a bit . Also I swapped out the crank set and gave the bike 7 more speeds to aid in going up hill and on rougher terrain . The first bike is already sold and another one is on the way for conversion -be first in line for spring !!!