My cruising speed is 55, the speed limit on anything other than interstates in Oregon. Mechanical brakes are not the limiting factor, the 525/550 18 tires are. I wouldn't make any irreversible changes. Would need to buy an extra rear end for modifications. An overdrive that would replace my freewheeling unit would be the best solution. Gear Vendor units with torque tube adapters are really long. Larrowe modifies Saggies to make third gear ovedrive and a linkage kit that retains the proper "H" pattern for about $3500.
3.54 gears are available for late 35 rear ends for about $900, so changing to that would be another option.
