Originally Posted by
dr1445
i had to move from 135", pedal to seat height to 137", to be able to get full rotation. did 6 miles the other day with the seat back at 135, some complaints for the first mile , then all went smoothly. so far no flare ups. did a 3 mile walk today as i mix up walks and rides, brilliant spring morning. if all is well tomorrow i will most likely try my old 10 mile route, last done in 2017. not a lot of hp here, not sure about the having to spin a 165 faster. currently running 170mm crank. thanks for the suggestion.
Interestingly, when you shorten your cranks by, e.g., 5 mm, you must then raise the saddle 5 mm resulting in a 10 mm difference when coming over the top of the pedal stroke... Interesting research that is easy to Google and has been printed many times on this forum showed that the optimum crank length was actually, 145 mm so, there's a lot to play with there. In any event, the effect on RPMs is usually positive not negative and also that longer cranks at any given RPM results in a faster foot speed which is the more relevant factor to consider. What some find is, when going to a shorter crank the RPMs go up which is good and the foot speed goes down in any given gear which the rider naturally accommodates for by increasing the gear with the result that power output is increased.