Is a cadence sensor worth it?

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Grandad
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Re: Is a cadence sensor worth it?

Post by Grandad »

Only slightly off topic but before the days of cycle computers checking cadence involved a watch and counting.

On an 84" fixed 25mph is 100rpm. Riding a 25 mile time trial with an Ingersoll stopwatch on the handlebars I used to count the revs, aiming to reach 100 before the second hand got back to 12 o'clock. This gave an immediate indication of whether I was inside or outside the magic hour at every point in the ride. Sadly it was usually bad news but occasionally exhilarating.
The fat commuter
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Re: Is a cadence sensor worth it?

Post by The fat commuter »

Fitted the computer yesterday. Haven't fitted the cadence sensor yet though.

The good news is that the LED bike light doesn't interfere with the wireless transmission. The bad news is that the heart rate monitor doesn't seem to update properly - it sometimes changes and other times will stay at the same rate despite me changing the amount of effort. Tested it whilst sat at my desk today at work and the readout will suddenly freeze. I suffer from something called ectopic beats and the display would freeze after one of these beats. I can't believe that this is the problem, but I'll keep monitoring (pardon the pun) it.
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Mick F
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Re: Is a cadence sensor worth it?

Post by Mick F »

[XAP]Bob wrote:It's not quite true though, a cadence of 400 wouldn't be high power.

There is an optimum range, and it will be a bit different for each of us. MickF's range is lower than some others, but that's fine.

Personally I work best at 90-100 rpm, so what - we're not clones...
No, we're not clones. We're all different.

I walked to the village and back the other day, thinking about this thread. I walk at a relaxed pace. I don't have particularly long legs, I'm not a natural runner or walker. I reckoned I was walking at about 60rpm ie my left foot went down once per second or thereabouts. I could keep going like that indefinitely uphill and down dale.

Do people who cycle naturally at 80 or 90rpm rpm walk faster than me, or maybe the same speed but with shorter paces?
Mick F. Cornwall
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[XAP]Bob
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Re: Is a cadence sensor worth it?

Post by [XAP]Bob »

My walking cadence is far slower than my cycling cadence.

Not really sure they should be related.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.
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Mick F
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Re: Is a cadence sensor worth it?

Post by Mick F »

I reckon that they are related, well, at least for me they are.
We've had this discussion before on here.

I climb stairs as if I'm cycling, and I walk as if I'm cycling. It's all about a "natural rhythm" for me. Beats per minute sort of thing. Sort of "clockwork" with a pendulum. Repetitive, regular, constant, drum-beat.

Maybe it's just me. :lol:
Mick F. Cornwall
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[XAP]Bob
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Re: Is a cadence sensor worth it?

Post by [XAP]Bob »

We have had this discussion. I just find that it I am more comfortable when I am pushing lighter and faster - but there is a natural rhthym for walking that is related to leg length
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.
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NATURAL ANKLING
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Re: Is a cadence sensor worth it?

Post by NATURAL ANKLING »

Hi,
[XAP]Bob wrote:We have had this discussion. I just find that it I am more comfortable when I am pushing lighter and faster - but there is a natural rhthym for walking that is related to leg length


You ride a bent also what crank length :?: Long legs too :?:
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope
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NATURAL ANKLING
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Re: Is a cadence sensor worth it?

Post by NATURAL ANKLING »

Hi,
http://www.me.utexas.edu/~neptune/Papers/msse32(7).pdf
2015-05-26_213332_a.jpg

Each line represents 100,200,300,400,500 watts respectively.
Showing that peak power is achieve at a particular cadence for that constant level of muscle activity.
As the power increases 100 200 300W etc, the peak of line has an increasing cadence.

The lines actually represent a constant muscle activation levels, efficiency comes at max power for that minimum muscle activity.

"Optimal cadence (cadence with lowest amplitude of EMG for a given power output) increased withincreases in power output: 57 +/- 3.1, 70 +/- 3.7, 86 +/- 7.6, and 99 +/- 4.0 rpm for 100, 200, 300, and 400 W, respectively.
Conclusion:
The results confirm that the level of muscle activation varies with cadence at a given power output. The minimum EMG amplitude
occurs at a progressively higher cadence as power output increases. These results have implications for the sense of effort and
preferential use of higher cadences as power output is increased."


"Although there is considerable discrepancy in the literature
with respect to preferred cadence (14,19,21), there is
general agreement that cyclists use a relatively high cadence
(11,19,21) and cyclists are more efficient at higher cadences
(11,29). It is also noteworthy that the world 1-h cycling
record has been consistently set with average cadence just
over 100 rpm (27). Assuming a sustained oxygen uptake of
5 Lzmin21, an efficiency of 25% and 20.93 kJzL21, the
power output during these efforts would be 419 W. This
level of sustained oxygen uptake would be feasible, based
on reports of elite cyclists (34), and 25% represents the
extreme upper level of reported values for efficiency in
cycle ergometry
(1,7)."

So if you wanted to produce power at a lower than optimal cadence more muscle activity would be needed.

If you are not racing or trying to kill yourself then at that power level you determine, would have a cadence of 70 say at 200 Watts.

It would be pointless in turning faster or slower at that power output, unless you are training (slower) for strength, higher than optimal efficiency, you are just activating muscles more and in time fatigue unnecessarily.

So its still more power at a higher rpm but only if you are putting out that power at the optimal rpm.

Obviously if you decide to output the same power as your cycling buddy at a lower than optimal RPM then you will fatigue faster than your buddy.

Of course if you are just tootling along at a relaxed pace then with low power output your cadence will not mater much as there will be little power loss and little early fatique.

I suppose that's why we don't see racers and hour attempts at 70 rpm.......how long would anyone last.


Mick F's claimed low average is probably not much different from mine when I am out training on mixed surfaces and a weighted MTB.
Mick F's hills will no doubt contribute to his lower cadence too, then you would say that what about his end 2 ends, by his own admission he cruises at 10 MPH overall on them and the terrain would average flatter than his training rides at the reduced effort, so lower power needed than home rides. Result is same cadence.
The pro's cruise at up to 75 rpm but race at 75 - 85 / 90 +.
If I am out training its normally at the moment very mixed and 1:5 hill on 50 Ib bike 30 " gear is probably 30 - 40 rpm.
On the flat.....................well I just worked it out.
Cycle path flat and gravelled 18 mph 80 - 94 rpm.
Fast road top gear 25 mph 100 rpm.
Dropping down base of haytor 30 mph 120 rpm.
Moderate pace road flat 22 mph 88 rpm.
Dropping out of top gear 20 mph 80 rpm.
Up 1:7 hill 5 mph 48 rpm.
up 1:5 hill 3mph 34 rpm.
Up railway track 12 mph 74 rpm.

All at average of 80 % of max HR.
On the turbo 80 - 91 avg max HR gives about 300 + watts :?:
So my assumption of my lowish cadence is wrong although I did have in my youth.
Maybe nowadays I just got smart, or its simply that at 24 mph I have run out of gears on the Skip Trainer :)

We all tend to rely on perceived efficiency but the gears and how fast we want to go play a large part on the true efficiency of our ride along with fitness.

P.S. I could use the redundant granny on the Skip Trainer but my idea is that its strength building....
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope
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Mick F
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Re: Is a cadence sensor worth it?

Post by Mick F »

NATURAL ANKLING wrote:Mick F's claimed low average is probably not much different from mine when I am out training on mixed surfaces and a weighted MTB.
Mick F's hills will no doubt contribute to his lower cadence too, then you would say that what about his end 2 ends, by his own admission he cruises at 10 MPH overall on them and the terrain would average flatter than his training rides at the reduced effort, so lower power needed than home rides. Result is same cadence.
Although those graphs are very interesting, they may be more generalising than factual?

You say that I cruise at 10mph.
Not correct.
I cruise faster than that, but I always reckon on 10mph average for a long day's ride. 100miles fully loaded will take you 10hrs door-to-door. This includes stops for rest, comfort breaks, food, sightseeing, going through traffic and junctions etc etc etc.

With hills, I personally have higher cadences. Just looking a segment I do regularly up from the Cornish/English border towards Tavistock, my cadence is (looking at my records) about 70rpm.

End2End with a cadence monitor was only on the Chopper, but for the record the overall average cadence was 65rpm.
I have a long ride info too. In 2011, I rode up the the Yorkshire Dales for a 100mile jaunt into the Dales up horrendous climbs and descents, and averaged 64rpm overall home-to-home.

As mentioned earlier, I've sold all the Garmin stuff and no longer bother with it as it's pointless for me. I ride to enjoy myself, not to train for a race. All the HR and cadence info was interesting and thought-provoking, but I've risen above it now and take it all with a pinch of salt.

Perhaps crank length and leg length come into all this? Maybe muscle lengths and diameters come into it too?
Some internal combustion engines have long strokes and some short, some are "over-square" and some "sub-square". They both rev differently for max torque and power.

We are all different. You'll be telling me next that when I swim I should use a certain strokes-per-minute for maximum speed. Maybe when I climb stairs I should do it a particular rate, or when I walk I should use a particular stride frequency and pace length?

Pinch of salt.

I'm being held up as an example because I'm a frequent poster on here and I'm prepared to nail my colours to the mast.
Mick F. Cornwall
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[XAP]Bob
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Re: Is a cadence sensor worth it?

Post by [XAP]Bob »

I think it's more than that MickF - I think you are at the lower end of what a "typical" range.

And no-one doubts that you put the miles in and have actually tried different methods. It's one of the most convincing "it varies by person" comments...


But - you are generally aiming for endurance, not outright speed, so define efficient? Does efficiency allow speed or endurance.

That's the gotcha - people say most efficient without actually saying that they mean most effective at <unknown target>
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.
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NATURAL ANKLING
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Re: Is a cadence sensor worth it?

Post by NATURAL ANKLING »

Hi,
I maybe started to misrepresent your average speed from memory, I couldn't look for the info you posted as I would probably struggle so I guessed a bit.

Yes we are all different and maybe its in our genes what pace you set.

Your own admission is that you have a low cadence so yes as a regular poster you are more than likely to be quoted, certainly no slight there :)

If you look at what I posted as I slow down and go up hill my cadence is slower.
So I am on that point opposite to you.
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NATURAL ANKLING
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Re: Is a cadence sensor worth it?

Post by NATURAL ANKLING »

Hi,
[XAP]Bob wrote:
That's the gotcha - people say most efficient without actually saying that they mean most effective at <unknown target>

True.
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope
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Mick F
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Re: Is a cadence sensor worth it?

Post by Mick F »

Efficiency to me, is the ability to go on indefinitely.

Efficient vehicles are vehicles that can travel using the least fuel possible. I can ride 100mile days back to back and think nothing of it physically, but then I don't try to do the 100miles as fast as I can.

Going back to hills, you need to get into a suitable gear (for you) and climb in comfort. Once down into bottom gear your cadence can't be increased unless you speed up. I find that I reach for bottom gear up a 1in6 maybe? Any steeper than that, my cadence has to go lower and lower and lower.

We live on a 1in4 and I have to climb it just to get home. I do maybe 2 or 3mph. The road is narrow with grass up the middle, so I only have a couple of feet width to go at that speed. 3mph in my bottom gear of 30r 28f = 24.5" is a cadence of about 40rpm. I cannot go into a lower gear, and I cannot go any faster when I'm tired after a long ride.

OK, I could fit a 34t sprocket and a 26t inner ring and be able to climb at 3mph at a cadence of 50rpm but I'm not complaining about my 40rpm. :wink:
Mick F. Cornwall
The fat commuter
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Re: Is a cadence sensor worth it?

Post by The fat commuter »

Well, the computer is being returned. The heart rate monitor would freeze every now and then. I worked out that it would stop working once the bike speed got above about 17 or 18 mph. So, I could cycle along the flat to the top of a slope and have a heart rate of 140 bpm. Freewheel down the slope at 20 mph for five minutes or so, get to the bottom where there's a junction and find my heartrate drops from 140 to, say, 80 in an instant. If I then increased my speed immediately then my pulse may go up to, say, 110 but then stay at that rate until my speed drops again.

I've tried with my light off, moving the computer head unit, doing a battery full - but no luck

It's this one, btw:

http://www.rosebikes.co.uk/article/sigm ... tAodKVYAew
Mark1978
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Re: Is a cadence sensor worth it?

Post by Mark1978 »

I have a cadence sensor but I can't see a readout when I'm on the bike. However looking at the results after a ride it's remarkable that I tend to keep a fairly constant 90-95 the most of the time I'm pedalling. So I guess I don't need a live readout
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