steve2k

I came across this article, on building a cadence meter for $12, via lifehacker and thought it might be interesting to people here, we often seem to talk about cadence.

https://www.instructables.com/id/Very...-Your-Bike-12/

flip18436572

You can get cadence on many cyclometers very cheap anymore. I think I paid less than $35.00 for my cyclometer with cadence and it is a Cat Eye Astrale 8.

Air

Great idea, thanks!

twobikes

I want to try this. My bike is a triple. The granny gear is steel, but it is small. The magnets could attach to the gear, not just to the bolts. Still, I would want to make magnet holders out of sheet metal for each magnet and run the bolts through the holder for a more secure attachment. Even then, I am not sure I can get the pickup close enough to the BB to "read" the magnets passing.

But, I had another thought I want to try first. I got a package of five button magnets at Radio Shack. One of them fits into the slight recess for the inner end of the left pedal at the crank. I would set the cyclometer for a wheel size of 1,666 mm rather than 3333 mm (1/5th of 16,666 mm) and multiply the display reading by 10 for my cadence. It seems like it should work and I would have a better magnet mount, as well as more room to mount the pickup coil.

twobikes

I have now tried the $12 cadence meter. I used one magnet stuck to the end of my left pedal where it fits into a nice little recess and will not easily come off. It is a round button magnet that came in a pack from Radio Shack. I programmed the cyclometer to a wheel size of 1667 and to read in Km/Hr. I ignore the decimal point in the display for a direct reading of my cadence. I made a bracket from heavy wire to bolt to the water bottle screws on the seat tube and to hold the pickup. This involved a little welding, but I have a welder.

As an accuracy check of the cadence meter I memorized my speed, cadence, and gear during part of today's ride. I used the following formula to see if the results equaled what I got from the meter: cadence = 336 x miles per hour/gear in inches. (336 is a constant.) The meter is accurate.

I had always thought my cadence was hopelessly stuck in the 60's and 70's, but discovered I actually hit 90 rpm for a while and was frequently riding in the 80's. I will use my new cadence meter to monitor my shifting from now on and will attempt to stay in the 80's.

It works very well.

Air

I love the fact you had to weld to get it to work - man after my own heart!

twobikes

I think a little careful experimentation with some paper to develop a pattern I could use to cut a mounting bracket out of galvinized sheet metal would have worked, but I try to weld whenever I can find an excuse.

I went on a 28 mile group ride yesterday and used the cadence meter to hold my cadence around 85. Whenever it dropped below 80 I shifted down. As soon as I shifted my cadence jumped to almost 90. People riding around me were starting to breathe heavily at the start of a slight upgrade. Not only did I not break a sweat, but I was passing people again and again. I did come home and take a hard nap afterward, though.