|Trace The Mitten|
...your feet which spins your wheels moves you along. I had always pushed harder gears to do around 60 rpm. As I started cycling again I kept hearing about the benefits of spinning above 70 rpms.
A friend let me borrow his mountain bike for a couple weeks. When I started to ride it I realized that I was not comfortable with the thumb shifting. I did not want to mess anything up on the bike. I definitely did not want to expose my ignorance and ineptitude, so I did not change gears all those hundreds of miles those weeks I rode the bike.
Luckily the gears were left in the middle positions. I would spin in 80+ rpms. I came to see that I was comfortable at that pace.
I later learned that you should spin with easy resistance as you build up your base.
Spinning in easy gears is easier on your joints. You are less likely to feel knee pain.
I am sure that had I used my own bike I would have pushed the harder gears earlier. I grew up the 'no pain, no gain' era. I was able to begin a good habit and prevent injuries. I went 5600 miles that year.
I can now shift with ease and I continue to improve on changing gears to maintain a steady cadence.
My advice is to spin in 80+ rpm and change gears as needed.