Personally, I don’t think it’ll be much more complicated to switch in 90° degree steps instead of 120°.
But there is no room inside of the gearbox to add a fourth gear pair that easy - I guess that is the bigger problem.
All you could do is to increase the gear ratio somehow; there are a few possibilities…well…it seems better to choose the word “challenges”…
- One can switch to chain drive; the chances to find a suitable primary chain transmission are much bigger than with a belt system (An odd way for my meaning, recommendable for racing or record Strida attempts only.)
- Another method for gear ratio increase might be the change to different rims; would we use 349er rims instead of 355er original ones (which are just 6 mm bigger) it could be feasible to ride Greenspeed Scorchers
These again are, due to their 40er width, 6 mm bigger (in diameter) than the biggest suitable 355er tyre and they would raise the gear ratio for ~ 3 %!
(Working on this right now.) - Finally it seems that in the near future we’ll get an alternative drive for the Strida!
Of course I’ll report about it asap.