Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

User Tag List

Reply
 
Thread Tools Search this Thread
Old 05-31-07, 02:45 AM   #1
sportsguru
Newbie
Thread Starter
 
Join Date: May 2007
Bikes:
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
can i make a cadence monitor

hi can anyone tell me if it is posable (and how 2) make a cadence monitor out of a spedometer , i have a few old cyclecomputers that i could put to use!

ie where to mount and how to programme the cyclecomputre
thankyou in advance
sportsguru is offline   Reply With Quote
Old 05-31-07, 07:43 AM   #2
twobikes
Healthy and active
 
twobikes's Avatar
 
Join Date: Mar 2007
Location: Caldwell, Idaho USA
Bikes: mid-60's Dunelt 10-speed, Specialized Allez Sport Tripple, Trek 7.2 FX
Posts: 887
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If you simply want to know your cadence, there is a formula you can use. When you are pedalling at the cadence you want to know, note the gear you are using. How many sprockets from the outside on the back and which chainring on the front? Note your speed. After your ride multiply the constant 336 by your speed in miles per hour and divide by your gear in inches.

As for converting a spedometer to measure cadence, it would seem an unlikely possibility. I am guessing, though. You might be farther ahead to start fresh with a reed switch for a sensor and an IC counter chip you can configure for events per minute. You would need to make your own case and mount. It could be fun, but would be involved.

Many say they used a cadence measuring spedometer for a while and later learned how to judge their cadence from experience. After a time they no longer used the cadence readout on their spedometer.

Last edited by twobikes; 05-31-07 at 12:03 PM.
twobikes is offline   Reply With Quote
Old 06-02-07, 09:40 PM   #3
ericgu
Senior Member
 
Join Date: Oct 2003
Bikes:
Posts: 1,941
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The answer is "yes".

There's no reason you can't mount a speedometer sensor on a crank, and it will give you a reading. The problem that you will have is that if you are riding at 100RPM, your computer might say something like 7mph, and you would have to figure out the conversion factor.

You might be able to play around with the tire size setting and switch between MPH and KPH to get a number that's easier to convert.
__________________
Eric

2005 Trek 5.2 Madone, Red with Yellow Flames (Beauty)
199x Lemond Tourmalet, Yellow with fenders (Beast)

Read my cycling blog at http://riderx.info/blogs/riderx
Like climbing? Goto http://www.bicycleclimbs.com
ericgu is offline   Reply With Quote
Old 06-04-07, 10:24 AM   #4
BILL SCHMIDT
Member
 
BILL SCHMIDT's Avatar
 
Join Date: May 2005
Location: WOODBURY, CT.
Bikes: LEMOND VERSAILLES, Surly Crosscheck
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Get or borrow a musician's metronome, set the cadience you want and pedal along at that cadience
while your speedometer is hooked up to your crank. Note the speed. Change the cadience on the
metronome and repeat the process several times until you generate a conversion chart between the registered speed and the cadience. You can then either post the chart on the bike or alter the dial readout.
BILL SCHMIDT is offline   Reply With Quote
Old 06-04-07, 11:11 AM   #5
socalslowguy
Senior Member
 
socalslowguy's Avatar
 
Join Date: May 2007
Location: Vista, CA
Bikes: 2006 Trek Madone 5.2
Posts: 153
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Sounds like a fun math problem so I broke out the calculator. If you set your computer to a tire circumfernce of 2682mm cadence will show as mph where each .1 mph = 1rpm. So 10.0 mph on the computer = cadence of 100 rpm. 7.5mph = cadence of 75 rpm etc.

You'll want to mount a magnet on one of the crank arms. A simple flat magnet held by wrapping electrical tape around the crankarm would work. The sensor can go on the chainstay.
socalslowguy is offline   Reply With Quote
Old 06-07-07, 05:18 PM   #6
UrbanChicago
Junior Member
 
Join Date: May 2007
Location: Chicago USA
Bikes: 1996 Gary Fisher Paragon
Posts: 11
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I suspect what you really want is for the computer to show you cadence as if it were speed. As in the computer reads 100 mph or 100 KM/h when your cadence is 100 rpm.

If your computer will accept your wheel circumference as 88ft (14ft radius) or 1666.67cm (265.4cm radius) if using KM/h, that will get you your desired results. But will the computer be able to display numbers that large?
UrbanChicago is offline   Reply With Quote
Old 06-08-07, 07:55 AM   #7
bh357
Senior Member
 
Join Date: Sep 2005
Bikes:
Posts: 169
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
http://www.63xc.com/martink/cadence.htm
bh357 is offline   Reply With Quote
Old 06-12-07, 04:26 AM   #8
sportsguru
Newbie
Thread Starter
 
Join Date: May 2007
Bikes:
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
interesting calclation

i am very interested in finding out the calulations that you used to get the quoted figure ?

i have now got 3 difering numbes to input and i am trying to workout which one is best/correct
sportsguru is offline   Reply With Quote
Old 06-12-07, 04:41 AM   #9
sportsguru
Newbie
Thread Starter
 
Join Date: May 2007
Bikes:
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
does the length of the crank make a differance to the input number??
sportsguru is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 01:04 PM.