ebuilder said:
The Madmadscientist said:
ebuilder said:
He should get a faster bike where human pedaling matters...lol.
You made a blanket statement and you were wrong. I routinely have top cyclists in my town draft me at 35mph + and I am contributing over 300w to the pedals. I have a FTP, functional threshold power of 275 watts and can easily sustain over 300w's for a few minutes when doing interval training.
BBSHD bike with 52/11 gear ratio maximum speed:
28 inch dia tire x 3.1416 = 87.96 in = 7.33 ft = .001388 mi. miles traveled for 1 wheel revolution
52/11 = 4.73 = .211 crank revolution per 1 wheel revolution
.001438 miles = .211 crank revolution
1 crank revolution = 0.00681 miles traveled
1 mile = 146.8 crank revolutions with 52/11 ratio and 700c/28mm wheel dia.
Posit max human sprinting RPM well within RPM capability of BBSHD ~170-180 spindle RPM
130 crank rev = 0.885 mile
130 crank rev/min = 0.885 mile/min
= 53.13 mph (power limited)
WP_20210725_15_04_18_Pro.jpg
Your post brings up an interesting question for me...
I have no idea what my happy cadence is. I only know that my prefered cadence seems to be slower than what I see when I'm out and about.
This is something that I've been meaning to figure out for a minute now. Can't really figure out a safe way to do it...
I could write a small book about this but will try to just touch on a couple of things.
Kinematics aka biomechanics of a rider matter greatly when it comes to sustainable cadence on any kind of a bicycle.
Cycling at let's say the elite amateur level is a skill. An equation. Every single aspect of a rider's position on the bike is scrutinized. The guys you see with immaculate pedal stroke who are high cadence riders, likely weren't born with it. Like a scratch golfer or top swimmer they arrived after great study and hard work.
Everything in the kinematic chain matters from cleat position to shoe varus/vulgas, hip angle, saddle setback. An equation. The more fit you are and the cleaner your pedal stroke the higher the RPM you can sustain on the bike.
The higher the cadence, the less your legs lactate and the more you lean on your cardio which good cyclist develop after years of training.
Watts= Torque (pedal force X crank arm length) X RPM.
With same pedal force turning a higher cadence, the more power you produce and the faster you ride.
A nominal cadence of 90 RPM is considered a good cadence for a performance rider and pretty close to what I generally ride. I am old and fit and probably top 2% for my age. I have been around bicycle racing for decades and have learned from many talented riders.
A small nitpick - I know you don't mean it this way, but it may SEEM that if going 90 cadence over 70 is better, than going 180 is double better
)
Cadence is all about *linear* muscle contraction speed in the end, and muscle physiology has a certain force/velocity relationship: the higher the SPEED of contration, the less FORCE muscles can generate, and this is by no means 'double the speed - half the force', relationship is much more complex and greatly depend your build, prevalent muscle type, 'weak links in the chain', etc!
Due to muscle recruitement principle, slow twitch, fat-burning, get recruited first, and as workload increases, more and more fibers get increased, including fast twich. (Btw, no single volunatry contraction can reqruite more than about 1/3 of the muscle mass - that's why direct electric stimulation by, say, electric torture or tetanic seizures can literally tear your ligaments - that's why 'feats of unnatural strengths' are sometimes possible... also, this: https://www.nature.com/articles/s41598-021-97949-2).
An other interesting tidbit: fat-burning slow twitch muscles are:
1. Less mechanically efficient
2. Require more oxygen to function
All in all, there is a
very complex interplay of multiple, mutually complementing and inhibiting factors. Unless you have a couch AND entire sports science laboratory at your disposal, it is extremely likely that your self-selected cadence is the best for your fitness level and power output, period, and don't listen to anyone that tell you otherwise.
As you get fitter and cycle harder, your average power output naturally increase - and so is your cadence. Cadence drills are like power lifting - good training tool, but cycling the way you do bench presses is terribly inefficient, and cycling is 90+% aerobic activity. Cycling at cadence faster than your 'preffered' one is even less so, actually.
