Typical cruising gears are in the 80s gear inches and climbing gears are 30s gear inches.
However, they will depend on personal fitness, and preferences. Use your existing set up as
the benchmark for any changes. Please also remember to consider the impact on chain length.
Note:
*1: Brompton 3 Speed -12%
*2: Brompton 3 Speed -18%
*3: Brompton 3 Speed standard ratio
*4: Brompton 3 Speed +8%