[Veselin Kolev]

Remember:

The number of moving parts squared is proportional to the probability of something going wrong.

If making a shifter adds too many more moving parts, reconsider your design. Apart from the pneumatic moving parts, there should not be that many more bearings or gears between a one speed and a two speed. However, there are two speed designs that only add 2 gears and two bearings, as in one more moving part. Keep it simple!