Those ratios were used on R50/5, R60's and R65's. They work great on a hack as long as you're running an 18" wheel and not looking for speeds above 70mph. Your hands will go numb. I prefer a 3:09(R90/6 or a 3:20(R75) and use a little more RPM between gears.
Originally Posted by Wirespokes
The lower ratios are the most popular for hacks - 3.36 and 3.56. I may have one of these I'd swap for a 3.0 or 3.09.