Hopefully this question won't make me sound utterly clueless. I really have no experience modifying bikes.
A while back, a friend was showing me their mountain bike, and mentioned that they had just installed a "granny gear". He let me try it, and I was rather amazed at how easy it was to peddle through sand and up hill. True, my feet were rotating about as fast as a ceiling fan, but the bike kept moving, which for me was unique. Typically, in sand or up big hills, I bog down and have to walk.
Is this possible with Rovers?
If possible, how does one go about it?