Has anyone out there changed the rover to a 2 or 3 cog crankset? If so where did you mount the derailers? Is this feasible with the internal 8 hub or will I need to swap out the rear wheel and gears? Please reply with pictures so I can show the bike mechanic it can be done. He also told me the frame where the rear wheel mounts does not have enough room to change out to a different wheel with gearing. I do go up hills in 4th gear currently. How much will this effect uphill climbing?