#46




Quote:
In terms of pedaling cadence, for a given power one can apply higher force on the pedals at a slower cadence, or lower force on the pedals at a faster cadence. But despite the legs moving faster at the higher cadence, higher cadences actually utilize more Slow Twitch muscles. This is because the muscle force (at a given power) is lower when the cadence is higher. The forum's own member Ti Designs talks about this a lot. Our posture on the bike has a large effect on the range of motions and utilization of our muscles. When bending your torso over the bars, you are probably getting your gluteous muscles into a range of motion where they can generate more power. Search more on the forum for Ti Designs discussions about this. 
#47




Quote:
Fp = (wg)(R/l)(tf/tr) where Fp = force at the pedal, in lb w = weight of bike and rider, in lb g = gradient; that is, sine of the angle of elevation. That seems to be how it is typically defined. l = crank length, R = rear wheel radius tr = rear teeth tf = front teeth The units for wheel radius and crank dont matter as long as they are the same. Changing weight by dw would change the force (dw*g)(R/l)(tf/tr) While changing teeth on the rear from tr to tr' would change the force (wg)(R/l)(tf)(1/tr'  1/tr) Equating these gives tr'/tr = w/(w+dw) So if you decrease weight by 5% it would feel the same as increasing rear teeth by a factor of 1/.95 or a little more than 5%. Doing this with the front teeth would give a simple direct proportion. We can also see that tr and w are proportional, so the same percent decrease in both would keep the force the same, for example going from 25 to 23 teethan 8% decrease and losing 13.6lbs from 170 to 156.4 would leave the force unchanged. It may seem odd that gradient drops out. But that is because we are dealing with proportions. Last edited by marciero; 05212024 at 05:01 PM. 
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