Cadence mathmaticians.

"David Brown :o)" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I've been looking for a cordless computer with cadence
counter but even non-cordless ones cost a fortune. Then it
occured to me, Doh! I ride a singlespeed so it can easily
be worked out from my speed. So could one of you please
take a peak at my calculations to check I

haven't

Quoted message said:

made any silly mistakes.

I ride a 32/16 ratio on a 26" wheel (measures
slightly under)

52"x pi = 163" of travel per rev. 1 mile = 63360" 1 mile =
389 revolutions

So far so good,

Quoted message said:

Therefore Cadence = 6.5 @ 1mph.

But.. but.. on a 32/16 each turn of the big ring causes two
turns of the small (and therefore of the whole wheel)? So to
do 389 revs of the rear wheel you have to turn the cranks
195 times? So if you turn it 195 times in one hour, that's
3.25 rpm.. isn't it?

Rich

Following on from David Brown :o)'s message. . .

Quoted message said:

I've been looking for a cordless computer with cadence
counter but even non-cordless ones cost a fortune. Then it
occured to me, Doh! I ride a singlespeed so it can easily
be worked out from my speed. So could one of you please
take a peak at my calculations to check I haven't made any
silly mistakes.

I ride a 32/16 ratio on a 26" wheel (measures
slightly under)

52"x pi = 163" of travel per rev. 1 mile = 63360" 1 mile =
389 revolutions

Therefore Cadence = 6.5 @ 1mph.

Thank you

A much simpler method
(1) Cycle 1/4 mile counting crank revs
(2) times 4 = revs per mile
(3) divide by 60 = conversion factor mph to revs per min

Even simpler method. Cycle at 10 mph for 1/2 minute counting
the revs Times 3 for 15mph cadence etc

IMHO bothering with cadence on a single speed is pointless.
The reason for measuring it is to help tune the gear ratios
and can be a handy input to something you can control. In
your case there's nothing you can alter so why bother?

--
PETER FOX Not the same since the submarine business went
under [email hidden]
www.eminent.demon.co.uk/wcc.htm Witham Cycling Campaign
www.eminent.demon.co.uk/rides East Anglian Pub cycle rides

"Richard Goodman" <[email hidden]> wrote
in message

Quoted message said:

Quoted message said:

I ride a 32/16 ratio on a 26" wheel (measures slightly
under)

52"x pi = 163" of travel per rev. 1 mile = 63360" 1 mile
= 389 revolutions

So far so good,

Quoted message said:

Therefore Cadence = 6.5 @ 1mph.

But.. but.. on a 32/16 each turn of the big ring causes
two turns of the small (and therefore of the whole wheel)?
So to do 389 revs of the rear wheel you have to turn the
cranks 195 times? So if you turn it 195 times in one hour,
that's 3.25 rpm.. isn't it?

Note the 52" x pi, not 26" x pi

"Richard Goodman" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

"David Brown :o)" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I've been looking for a cordless computer with cadence
counter but even non-cordless ones cost a fortune. Then
it occured to me, Doh! I ride a singlespeed so it can
easily be worked out from my speed. So could one of you
please take a peak at my calculations to check I

haven't

Quoted message said:

made any silly mistakes.

I ride a 32/16 ratio on a 26" wheel (measures slightly
under)

52"x pi = 163" of travel per rev. 1 mile = 63360" 1 mile
= 389 revolutions

So far so good,

Quoted message said:

Therefore Cadence = 6.5 @ 1mph.

But.. but.. on a 32/16 each turn of the big ring causes
two turns of the small (and therefore of the whole wheel)?
So to do 389 revs of the rear wheel you have to turn the
cranks 195 times? So if you turn it 195 times in one hour,
that's 3.25 rpm.. isn't it?

He's doubled the (nominal) wheel size. The calculations are
more-or-less correct, but, of course, by approximating and
rounding in several places there is going to be an error
built in. Not particularly significant, though.

---
Outgoing mail is certified Virus Free. Checked by AVG anti-
virus system (grisoft.comgrisoft.comOpen ↗). Version: 6.0.688 /
Virus Database: 449 - Release Date: 18/05/2004

"David Brown :o)" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I ride a 32/16 ratio on a 26" wheel (measures
slightly under)

52"x pi = 163" of travel per rev.

No. 26" is the diameter, unless you really have a 4'4" high
wheel. Circumference is 2 pi r or pi d.

Quoted message said:

1 mile = 63360"

Yes.

Quoted message said:

1 mile = 389 revolutions

No, 776 revolutions, due to above error. Hence 12.9rpm/mph.

That's a really, really low gear. Are you sure you ride
32/16? I'd struggle to maintain 10mph on your bike.

--
Mark.

52"x pi = 163" of travel per crank revolution 1 mile =
63360" 1 mile = 389 crank revolutions

Therefore Cadence = 6.5 @ 1mph.

"David Brown :o)" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

"Richard Goodman" <[email hidden]> wrote
in message

Quoted message said:

Quoted message said:

I ride a 32/16 ratio on a 26" wheel (measures slightly
under)

52"x pi = 163" of travel per rev. 1 mile = 63360" 1
mile = 389 revolutions

So far so good,

Quoted message said:

Therefore Cadence = 6.5 @ 1mph.

But.. but.. on a 32/16 each turn of the big ring causes
two turns of the small (and therefore of the whole
wheel)? So to do 389 revs of the rear wheel you have to
turn the cranks 195 times? So if you turn it 195

times

Quoted message said:

Quoted message said:

in one hour, that's 3.25 rpm.. isn't it?

Note the 52" x pi, not 26" x pi

Ah yes of course, circumference = 2 pi r and you did 2 pi d.
So yes, you did the gear doubling at first stage.

Rich

"Mark Tranchant" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

"David Brown :o)" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I ride a 32/16 ratio on a 26" wheel (measures
slightly under)

52"x pi = 163" of travel per rev.

No. 26" is the diameter, unless you really have a 4'4"
high wheel. Circumference is 2 pi r or pi d.

Yes, and he's taken the gearing into account. If his gear
had been 52/13, the numbers would have been 104" * pi = 326"
of travel per rev. Gear inches work this way.

Quoted message said:

Quoted message said:

1 mile = 63360"

Yes.

Quoted message said:

1 mile = 389 revolutions

No, 776 revolutions, due to above error. Hence
12.9rpm/mph.

That's a really, really low gear. Are you sure you ride
32/16? I'd struggle to maintain 10mph on your bike.

And that should give you the clue that your sums are wrong -
think for yourself what a 32/16 gear on a 26" wheel is like.

cheers, clive

"Peter Fox"
<[email hidden]>

Quoted message said:

IMHO bothering with cadence on a single speed is
pointless. The reason for measuring it is to help tune
the gear ratios and can be a handy input to something you
can control. In your case there's nothing you can alter
so why bother?

I'm working the other way 'round..... 95% off my riding is
at a pretty constant speed as I ride riverbanks that are
bumpy but obviously flat. I can use my ideal cadence to work
out gear ratios as I get fitter.

David Brown :o) said:

I've been looking for a cordless computer with cadence
counter but even non-cordless ones cost a fortune. Then it
occured to me, Doh! I ride a singlespeed so it can easily
be worked out from my speed. So could one of you please
take a peak at my calculations to check I haven't made any
silly mistakes.

I ride a 32/16 ratio on a 26" wheel (measures
slightly under)

52"x pi = 163" of travel per rev. 1 mile = 63360" 1 mile =
389 revolutions

Therefore Cadence = 6.5 @ 1mph.

Thank you

There is an easier, if slightly more expensive method, which
does not require the user to tax his/her brain whilst
enjoying the scenery. *

1. Buy a dirt cheap Cycle Computer.

2. Stick the magnet on the crank and mount the sensor
accordingly.

3. Set the wheel size to 1.667 metres or 166.7 centimetres
or even 1667 millimetres depending on type of computer.

4. A reading of 6.5 kilometres per hour will indicate a
cadence of 65 revolutions per minute. (Just ignore the
decimal point)

Terry Duckmanton

* Not a mathematician, can you tell?

"Terry D" <[email hidden]> wrote in message
news:jprrc.472$X64.267@newsfe3-gui...

Quoted message said:

There is an easier, if slightly more expensive method,
which does not require the user to tax his/her brain
whilst enjoying the scenery. *

1. Buy a dirt cheap Cycle Computer.

2. Stick the magnet on the crank and mount the sensor
accordingly.

3. Set the wheel size to 1.667 metres or 166.7 centimetres
or even 1667 millimetres depending on type of computer.

4. A reading of 6.5 kilometres per hour will indicate a
cadence of 65 revolutions per minute. (Just ignore the
decimal point)

Aksherly that sounds like quite a good way of getting a
cheap cadence display, given that computers with this
function built in tend to be a bit expensive - and it would
be one that is always 'on' while you can have speed
displayed on another computer. Good tip!

Rich

Richard Goodman said:

Aksherly that sounds like quite a good way of getting a
cheap cadence display,

An even cheaper and easier way is to use Sheldons online
gear calculator. Easy as point, click, print.

sheldonbrown.comindex.htmlOpen ↗

You can use this to calculate and print a small chart
showing cadences at a variety of speeds. I have one
sellotaped to the stem of my hack showing cadence in
different gears at 15mph and 20mph. Gives a good estimate
without bothering to buy a cadence capable computer.
--

"Bob"

'The people have spoken, the [censored]'

Email address is spam trapped. To reply directly remove
the beverage.

Isn't cadence was the speed of rotation of the cranks?

If so count your pedal revolutions over 15 seconds (from a
cycle computer) and multiply by four for rpm!

--
Wallace Shackleton,

Kinross, Scotland.

Cycling in Kinross-shire www.cyclekinross.org.uk

Wallace Shackleton said:

If so count your pedal revolutions over 15 seconds (from a
cycle computer) and multiply by four for rpm!

Hi Wallace

I don't have a cycle computer and counting revs accurately
is almost impossible without one. My counting automatically
gets in time with my pedalling. The minus side to this is
that i have no real way of knowing my true cadence: the plus
side is that my rpm can be anything I wish!

However, if i were to take a guess, I would say that I pedal

Quoted message said:

75rpm but <100rpm, which suits me, sir.

James