I’ve been out cycling a little bit recently and I have been enjoying it. As a calorie burner it’s not as efficient as running/jogging but it is a different activity and fun. Also, as I can cycle three to four times faster than I can run and because of the increased time needed to burn fat I now have somewhere between 9 and 25 times the area to investigate – it depends on a number of factors but is essentially the length scale factor squared.
When I’ve been out I’ve been changing gear but I have been wondering what the actual ratios are and understanding these would make things a little more efficient and help me know when it’s best to change from big to small etc. The bike is an 18 speed machine which I find surprising but then I’m slightly old and can remember 5 speed derailleurs being impressive technology. I looked up the number of teeth on each gear and created a spreadsheet.
This now means that I understand the numbers more and can change into a more correct gear given the upcoming terrain. All the above are in the form 1 : n, where it is turns of pedal : turns of wheel. On a more fundamental level I think I am surprised at how efficient we are at cycling and it should be done more, if you can get a bike.