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Discussion Starter #1 (Edited)

For most builds, or purchases, people should take into consideration the pedal assist capability of the bike.

(RPM - crank-pedal Revolutions Per Minute - pedal rate)
60 rpm is considered a casual-sustainable rate
90 rpm is, a more, top sustainable rate

Figured - rpm x ratio x wheel size = mph

(rpm x 60min) x (Front T / Rear T) x (Wheel " x 3.14) / 63360 = mph

26" wheels - My EZip Trailz (OEM)
(60rpm x 60min) x (44T/14T) x (26" x 3.14) / (12" x 5280') = 14.57mph
(90rpm x 60min) x (44T/14T) x (26" x 3.14) / (12" x 5280') = 21.86mph

26" wheels - My EZip Trailz (w/32-11T upgrade)
(60rpm x 60min) x (44T/11T) x (26" x 3.14) / (12" x 5280') = 18.55mph
(90rpm x 60min) x (44T/11T) x (26" x 3.14) / (12" x 5280') = 27.83mph

26" wheels - My Black Widow (Upgraded 34-11T)
(60rpm x 60min) x (48T/11T) x (26" x 3.14) / (12" x 5280') = 20.24mph
(90rpm x 60min) x (48T/11T) x (26" x 3.14) / (12" x 5280') = 30.35mph

27" Wheels - My old 12 speed
(60rpm x 60min) x (52T/12T) x (27" x 3.14) / (12" x 5280') = 20.87mph
(90rpm x 60min) x (52T/12T) x (27" x 3.14) / (12" x 5280') = 31.31mph

700c = 28" wheels - My Haro Express Deluxe
(60rpm x 60min) x (48T/11T) x (28" x 3.14) / (12" x 5280') = 21.80mph
(90rpm x 60min) x (48T/11T) x (28" x 3.14) / (12" x 5280') = 32.69mph

29'er Wheels
(60rpm x 60min) x (48T/11T) x (29" x 3.14) / (12" x 5280') = 22.58mph
(90rpm x 60min) x (48T/11T) x (29" x 3.14) / (12" x 5280') = 33.86mph
 

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For most builds, or purchases, people should take into consideration the pedal assist capability of the bike.

(BPM - Beats Per Minute - pedal rate)
60 bpm is considered a casual-sustainable rate
90 bpm is, a more, top sustainable rate

Figured - bpm x ratio x wheel size = mph

(bpm x 60min) x (Front T / Rear T) x (Wheel " x 3.14) / 63360 = mph

26" wheels - My EZip Trailz (OEM)
(60bpm x 60min) x (44T/14T) x (26" x 3.14) / (12" x 5280') = 14.57mph
(90bpm x 60min) x (44T/14T) x (26" x 3.14) / (12" x 5280') = 21.86mph

26" wheels - My EZip Trailz (w/32-11T upgrade)
(60bpm x 60min) x (44T/11T) x (26" x 3.14) / (12" x 5280') = 18.55mph
(90bpm x 60min) x (44T/11T) x (26" x 3.14) / (12" x 5280') = 27.83mph

26" wheels - My Black Widow (Upgraded 34-11T)
(60bpm x 60min) x (48T/11T) x (26" x 3.14) / (12" x 5280') = 20.24mph
(90bpm x 60min) x (48T/11T) x (26" x 3.14) / (12" x 5280') = 30.35mph

27" Wheels - My old 12 speed
(60bpm x 60min) x (52T/12T) x (27" x 3.14) / (12" x 5280') = 20.87mph
(90bpm x 60min) x (52T/12T) x (27" x 3.14) / (12" x 5280') = 31.31mph

700c = 28" wheels - My Haro Express Deluxe
(60bpm x 60min) x (48T/11T) x (28" x 3.14) / (12" x 5280') = 21.80mph
(90bpm x 60min) x (48T/11T) x (28" x 3.14) / (12" x 5280') = 32.69mph

29'er Wheels
(60bpm x 60min) x (48T/11T) x (29" x 3.14) / (12" x 5280') = 22.58mph
(90bpm x 60min) x (48T/11T) x (29" x 3.14) / (12" x 5280') = 33.86mph
Why wouldn't you use "RPM", the industry standard for things that go 'round, and save BPM for heart rate, also an industry standard?
 

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RPM sounds more associated with tire speed.
PC for Pedal Cadence was way too confusing.
BPM - Beats Per Minute - from the music industry, as in timing and music, seemed most appropriate.(In fact, cadence is also a musical term)
Many bikers tend to train, and adapt their pedal cadence, to the beat of various musical numbers, "getting their timing and rhythm right."

And ... "Beats Per Minute - pedal timing", seems perfectly clear ... ?
How can "pedal cadence" be too confusing, when cadence is the basis for all things cycling? This is a bicycle forum. Despite the rubbish you have just posted about musical numbers, any cyclist that that is doing any sort of real training is concerned with maintaining a certain cadence (which is the RPM of their cranks) and keeping their heart rate (BPM) within a specific range.

Besides, a gentlemen whose untimely passing followed my father's by two weeks has already provided the cycling world with this handy calculator.

Cheers,

Industry "Knows his resources" Hack
 

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I figured it was a DJ thing. iTunes database allows music to be sorted by BPM. Should a rider select music for his iPod that matches his desired heart rate or pedal cadence?
 

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Discussion Starter #7
I figured it was a DJ thing. iTunes database allows music to be sorted by BPM. Should a rider select music for his iPod that matches his desired heart rate or pedal cadence?
The program is designed for training your pedal cadence.
Music has long been used as a physical training aid, for developing ... rhythm.
Hence the musical cadence from Army drill Sergeants.
Teaching the lowly grunts, how to shuffle their feet.
(Sorry ... Armed forces drill training! Didn't intend to slight any branch.)

Of course, you should monitor your heart rate, at least during training,
Much of the purpose of training, is to find your optimal cadence, then to gradually improve upon it. (duration, speed, effort - singularly, or combinations, thereof)

To improve your muscular efficiency!
And yes, your heart is one of those muscles.
 

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I like to listen to The Pretenders "Back on the Chain Gang" when I ride.
My guess is that The Pretenders would make a ride much more enjoyable than something like Pantera. Does that happen to coincide with a higher cadence, or a lower one? Because if you follow Gunnie's approach, you'll be at the back of the pack, grinding along at 60 RPM.
 

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Actually the rhythm works nicely as 120 BPM
The same rhythm works nicely at half rate speed, for 120 RPM.
Just adjust the timing, to revolution per footfall, instead of revolution per 2 footfalls.
In fact a cycling music site lists music by both speeds.
Best Cycling Songs
Between your incorrect use of acronyms and the simple comma, it's becoming more difficult to even follow your faulty logic.

A military march incorporates an average cadence of 120 RPM, but a footfall is not equal to a rotation of the cranks, since it is a step, rather than a revolution, and thereby the count will be twice as high. So it actually equates to a cycling cadence of 60 RPM, which is not so good on the joints, nor would it be an efficient use of the cardiovascular system. On the plus side, the website you linked to may be handy for those that cannot multiply or divide by two.
 

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It its not incorrect to use an abbreviation after first defining it. ViB defines his acronym (and upon interrogation explains why he didn't use RPM which might have been used without including definition). His post is correctly written if of limited usefulness.

Another I like to listen on rides;

The Wheel
(Garcia/Hunter/Kreutzmann)


The wheel is turning and you can't slow down,
You can't let go and you can't hold on,
You can't go back and you can't stand still,
If the thunder don't get you then the lightning will.

Won't you try just a little bit harder,
Couldn't you try just a little bit more?
Won't you try just a little bit harder,
Couldn't you try just a little bit more?

Round, round robin run round, got to get back to where you belong,
Little bit harder, just a little bit more,
A little bit further than you gone before.

The wheel is turning and you can't slow down,
You can't let go and you can't hold on,
You can't go back and you can't stand still,
If the thunder don't get you then the lightning will.

Small wheel turn by the fire and Rod,
Big wheel turn by the grace of God,
Every time that wheel turn 'round,
Bound to cover just a little more ground.

The wheel is turning and you can't slow down,
You can't let go and you can't hold on,
You can't go back and you can't stand still,
If the thunder don't get you then the lightning will.

Won't you try just a little bit harder,
Couldn't you try just a little bit more?
Won't you try just a little bit harder,
Couldn't you try just a little bit more?
 

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It its not incorrect to use an abbreviation after first defining it. ViB defines his acronym (and upon interrogation explains why he didn't use RPM which might have been used without including definition). His post is correctly written if of limited usefulness.

Another I like to listen on rides;

The Wheel
(Garcia/Hunter/Kreutzmann)

[snip]
He's trying to present information that he thinks other people might find useful, but fails to realize that there's already widely accepted acronyms for his equation. Imagine someone trying to apply that new found knowledge at their LBS, and suggesting to the salesperson that they are most comfortable at 60 BPM.

I've always like the Dead, and even saw them in the 80's, in Long Beach. Not my crowd though. Of course, I'd rock one of Jerry's ties any time.
 

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Discussion Starter #16 (Edited)
120? But you've suggested "90rpm is, a more, top sustainable rate".
Max recommended sustainable output seems to be at just around 100 - PPR (Preferred Pedal Rate)
Preferred Pedal Rate: An Index of Cycling Performance

Of course, since I often Sprinted my oem EZip at 25mph+
"26" wheels - My EZip Trailz (OEM)
(60rpm x 60min) x (44T/14T) x (26" x 3.14) / (12" x 5280') = 14.57mph
(90rpm x 60min) x (44T/14T) x (26" x 3.14) / (12" x 5280') = 21.86mph"
That means , for sprints, I often, briefly maintained ~115rpm.

And with my upgrade EZip I've attained 35mph with favorable tailwinds, and while drafting and on slight downgrades.
26" wheels - My EZip Trailz (w/32-11T upgrade)
"(60rpm x 60min) x (44T/11T) x (26" x 3.14) / (12" x 5280') = 18.55mph
(90rpm x 60min) x (44T/11T) x (26" x 3.14) / (12" x 5280') = 27.83mph
"
Which is pushing near to 120rpm! By an old man in his mid 50's, with a bad heart.

Now I'm certain that my efforts could be exceeded by young, healthy, trained
athletes.
But, yes! Maximum sustainable PPR seems to be right near the 90rpm rate.

Sprints ... on the other hand are brief surges of speed, possibly pushing, well beyond the 120rpm range.
Spinning classes, indoor training etc, (places you should listen to music), might greatly exceed that, due to limited resistance?
 

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Discussion Starter #17 (Edited)
L********e said:
Good info, however, does it also take into account the extra torque needed for the higher speeds? The legs/motor still need to be able to maintain that kind of sustained power, and then there are the aerodynamic considerations, going from 20 MPH with X watts, isn't going to make 30 MPH with the same wattage even though you have mechanical advantage with gearing. ;)
No, just pedal speed capability.

However ... variations of motor and gearings show the following, (real world), motor only top speeds, for my mountain bike style:
450 watt = 21-22 mph
675 watt = 27 mph
750 watt (1HP) = 30 mph
832 watt = 32 mph? (estimated from 44.4V pack)
(based on Li-ion batteries w/full charge)
"watts" are motors output watts ... not input watts.
Through a typical brushed permanent magnet motor, input watts would be ~20 - 25% higher.
Through a typical brushless permanent magnet motor, input watts would be ~15 - 20% higher.

I, of course, would like to keep my pedal assist capability, at noticeably past , motor only speed.
There is still motor assist applied, past the motor only speed ... it's just waiting ... for a little help, from me!

I can push my 675 watt, (27mph), EZips, past 30 mph, even to 35mph ... with a tailwind, or drafting.
 

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Discussion Starter #19
No, just pedal speed capability.

However ... variations of motor and gearings show the following, (real world), motor only top speeds, for my mountain bike style:
450 watt = 21-22 mph
675 watt = 27 mph
750 watt (1HP) = 30 mph
832 watt = 32 mph? (estimated from 44.4V pack)
(based on Li-ion batteries w/full charge)
"watts" are motors output watts ... not input watts.
Through a typical brushed permanent magnet motor, input watts would be ~20 - 25% higher.
Through a typical brushless permanent magnet motor, input watts would be ~15% higher.

I, of course, would like to keep my pedal assist capability, at noticeably past , motor only speed.
There is still motor assist applied, past the motor only speed ... it's just waiting ... for a little help, from me!

I can push my 675 watt, (27mph), EZips, past 30 mph, even to 35mph ... with a tailwind, or drafting.
Took a bit of searching, but I found my graph, of gearing-voltage comparisons.
I even factored in road load and wind resistance:
 

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Discussion Starter #20 (Edited)
Personally, my target speed for an eBike, or eaBike is 30mph.
This allows smooth blending with local traffic.
With a mountain (style) bike, I would estimate that 30mph (motor only) would require a 750watt motor (1hp), and proper gearing, of course.
A "road" bike (racing style) would require considerably less, possibly 500watt, due partly to less "road load", but mainly due to reduced wind resistance.
"Road load" might be a major factor, below 20mph, but beyond that, wind resistance, increases resistance, exponentially.
 
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