> On Apr 1, 2025, at 1:44 PM, Bill Lindsay <[email protected]> wrote: > > No, that is not an April Fool's Joke. 110RPM is a spin, but a do-able spin > for a spinner, and I consider myself a spinner > > 90-110 is pretty well established as the range that is most efficient. When > I do my gear calculations for single speed and other low-gear-count builds, I > calculate how fast I'll be going at 60RPM and how fast I'll be going at > 110RPM. So, for example, my RoadUno has two gears: 42 inches and 67 inches. > My low gear will go 7MPH at 60RPM. My high gear will go 22MPH at 110RPM. So > that bike is good for speeds in between 7MPH and 22MPH. > > When people tell me they can't (or don't want to) ride at 110RPM I tend to > believe them. >
Well, according to Grant, pretty much nobody on a Rivendell should be riding at a cadence of 90rpm. According to science, however, everybody has their own preferred cadence, and the cadence that is optimal for them (meaning most efficient power delivery) is rarely far from their preferred cadence. I’ve not seen any science that shows 90-110 is the most efficient. I do the same as Bill with my gear charts, except I use 75-100rpm, with a mid-point of 87. That’s about a 15% difference between the mid-point and the end-points, which is a change in cadence that I find meaningful but not disruptive. Thus, I look for 15% differences between cogs as ideal for me. My preferred gear chart metric is kph @ 87rpm. My personal observations are: - I can spin fine at 120rpm (in sneakers on Clem pedals, no less) but I prefer not to spin that fast - I can loaf along fine at 60 rpm, but I prefer not to go that slow unless I’m cruising down hill or down wind - very often on a long ride if I have a down hill or down wind section I will ride at a low cadence to rest my legs but keep them moving - level of effort makes a gigantic difference - the harder I’m riding, the more important it is to keep my cadence in a narrow range - related to that - up hill (or up wind) vs down hill makes a gigantic difference - when you are working against gravity (or a big head wind) every time your foot speed slows and you then have to speed it up again, the speeding up again costs energy. “Pedaling squares” is what us old timers call it. As cadence slows it becomes more difficult to maintain a constant angular velocity; your cranks speed up in the power part and slow down in the dead spots. All that acceleration and deceleration is wasted energy. I find that it gets harder to maintain constant foot motion as cadence drops below 75; and below 60, if there’s any significant drag, it’s almost impossible _for me_ (I can’t emphasize enough… for me!). - Power = torque * angular velocity. I have skinny, weak legs, so don’t generate anywhere near as much torque at the BB as others. I have to make up for that with angular velocity. Ted Durant Milwaukee WI USA -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/rbw-owners-bunch/71CB18A8-39FB-4170-BF8A-9AC2D446FC82%40gmail.com.
