wislander

I need a relatively cheap (under 50 euros) device to measure cadence, preferably something that I don't have to connect to my phone. Is Sigma BC 14.16 STS CAD any good? Are there any other options?

John_V 

My wife had a Sigma computer with cadence (BC16-12) and it worked great. Unfortunately, the cadence sensor was the first thing to go on it. Otherwise, it’s a great non-GPS computer.

dabac

You can use the speedo function of a basic bike computer as a cadence counter. Put the magnet on the crank, the pickup on the chainstay and program it with a calculated fake wheel diameter.
The number will be correct, but the decimal point will be off.
If you set the Computer to wheel circumference 1667 mm, the kmh reading will be 1/10 of your cadence.
If your computer accepts a wheel circumference of 16.67 metres, kmh will equal cadence. Not all computers accepts that though.

Steve B.

Wrist watch, count your pedal strokes for 20 sec., multiply by 3 ?.

I’ve always been puzzled by the need for a cadence readout. After a few decades I know my usual cadence is around 80-85. Not sure what else I need to know and or how knowing that helps me.

Seattle Forrest

You said you don't want to have to use it with your phone, how are you going to use it? Do you already have a computer (Garmin? Wahoo?) or do you mean a cheap cat eye style?

Elvo

Garmin and Wahoo sensors are like $35

wislander

I am a beginner, so I don't have anything yet. Do you think that buying a full-blown computer would make sense, given that I use my bike for 4-5 hours a week only and usually go on the routes I already know?


I don't have a lot of experience and some previous knee issues, so I'd like to make sure I am hitting 80-90 rpm (especially on the hills).

Trakhak

Just looked up that Sigma computer. Very impressive list of features, especially for the price.

That said, for the cheapest cadence determinant, here's how I think about it: if I don't know whether I should shift to an easier gear, it means that I should shift to an easier gear.

Which reminds me of an off-topic but delightful quote from Robbie McEwen, who was a professional bike racer from Australia who won many sprint stages in the Tour de France in the early to mid-2000s. Asked after a photo-finish Tour sprint stage whether he knew that he'd won, he said, "You don't always know when you've won, but you always know when you've lost."

(I'd have liked the interviewer to follow up: "But, Robbie, doesn't that mean that if you'd don't know whether you won or lost, you must have won?")

Pop N Wood

Bike computers and even GPS units are a bit of a toy. But they can add to the enjoyment of riding the bike. So yes, it would make sense for you to buy one.

I like the speedo and knowing how far I have ridden. Many even have clocks with time of day, that can be very useful, better than pulling out your phone or wearing a watch if you have somewhere you need to be.

Bike computers can be relatively inexpensive and the batteries can last a year or more. I prefer the wireless models, wires get in the way and clutter the bike. GPS units are larger, need to be charged much more often, and can get expensive.

canklecat

XOSS and comparable low priced dual purpose speed/cadence sensors are available for around $20-$25 each or $40 per pair. They're switchable from speed to cadence by removing and reinserting the battery while checking the LED color change. They work fine.

Pair 'em with any free or low cost activity app on your smart phone. Wahoo Fitness is free and works well. Cyclemeter offers more features and costs $10 a year. Neither automatically shares your ride data online unless you choose to. Of the two, Cyclemeter is probably the most secure and private (for folks who are concerned about that stuff).

The XOSS G+ is the lowest cost bike computer that's compatible with most sensors (other than power meters). I use one with my old Wahoo wired speed/cadence sensors (ANT+ only), newer Wahoo Tickr (Bluetooth or ANT+) and XOSS speed/cadence sensor (also Bluetooth/ANT+).

I've had no problems with my XOSS G+ but tech support is practically non-existent. Apparently they planned a major launch of a China based rival to Strava for 2020, of which XOSS is a sub-company. But the coronavirus pandemic hit China hard and by January XOSS was responding to customer posts on Facebook only once a month or so. However they are still making products and maintaining the computer firmware and app with occasional upgrades and improvements. They just don't respond to customers online. I suppose with limited human resources they're concentrating on product. If customers have problems I suppose they can file a claim through Amazon, the main vendor.

But if you don't need a realtime display on your handlebar/stem that lasts longer than a phone display, you won't really need a computer for now.

I use a computer mostly to track my heart rate, time and distance. I modified my cadence last year, switching from spinning around 90-100 rpm to a more natural cadence of 60-75 rpm. Works better for me at age 62. My heart rate is lower, my legs are stronger, no knee problems. The whole cadence issue tends to take on cultish tones so do whatever works best for you.

Before then I used my old iPhone 4s on the stem but it lasted only a couple of hours with the display on, so that got old pretty quickly on longer rides. And even the smaller phone was much larger and heavier than most bike computers. The XOSS G+ is about the same size and weight as non-GPS computers like the CatEye models. Costs about the same too. No really reason not to get a good low cost GPS computer now. Lezyne and Bryton also sell good low cost GPS computers now.

Seattle Forrest

It sounds like you'll need something that can display the cadence number for you as it's measured. That could be a phone, it could be an expensive GPS computer with all kinds of features, it could be a $50 Cateye. If you don't have any other reason to choose one over the other, go for the least expensive option.

fietsbob

stop watch.. count pedal strokes ..

Musician's metronome is adjustable in beats per minute.. there are electronic ones with headphone jacks now..
https://www.musiciansfriend.com/metronomes I see one is even in a wristwatch format..







...

Amt0571

I bought a no brand ANT+ sensor from Aliexpress for 8€. It works, but tends to spike over bumpy terrain.

I then bought a Magene ANT+ sensor, also from Aliexpress, for 13€. It works perfectly well with no spikes.

I have kept the no brand one on the road bike, as it doesn't spike a lot there, and use the Magene one on my mountain bike.

Iride01 

80-90 rpm isn't a magic number on hills for knee issues. What is magic for knee issues is just learning to shift to a lower gear when ever you feel like you are putting a lot of muscle into pedaling.

If you don't have a low enough gear for what you ride, then your money will be better spent on resolving that. Knee problems have other causes too on bikes. Almost all causes have a remedy if they are a result of cycling.

Seattle Forrest

That's not a helpful answer.

fietsbob

if you are practicing music performance a Musician's metronome has dual uses..

minnesotabob

Just for fun I've been developing an Android app to measure cadence using the phone's own internal accelerometers. No external sensor needed. It is not yet in the Play Store because I don't know exactly what I should do with it, not knowing if such a thing is even useful. After reading this thread I am beginning to think maybe it is. What you do is just put the phone in your pocket and start riding. Even the smallest amount of tilt is enough for my app to detect cadence in most cases. It doesn't work with an irregular cadence, or on a very bumpy road. It requires 10 seconds of pedaling at a constant rate. It displays the RPM on the screen (which is useless while it is in your pocket) and it also speaks the RPM with the Android text-to-speech conversion, which is a bit more useful. You might have a hard time hearing it in traffic, but on a quiet bike path it is quite audible. Of course one could wear ear buds, but that seems kind of inconvenient. I could log the readings for later review.

So help me out here. Is this an idea worth pursuing? Or should I just put it back on the virtual shelf? It was quite a challenge making it work in a variety of positions and extracting the RPM from a very noisy signal. I ended up using autocorrelation, if any of your are interested in signal processing. But really, what should I do with this half-finished app?

fourfa

I think you'll find many cyclists interested in cadence have no pockets on the legs of their cycling shorts and bibs...

Sounds like a fun project and I don't want to discourage, though. Is it possible to make it broadcast to a bluetooth-compatible bike computer as if it were a normal cadence sensor? I don't know how controlled the BT I/O is on android...

minnesotabob

Yes, I could do that. I mentioned that in another thread. But then you would need two phones - one to be the sensor and the other to be the display.

fourfa

I mean one phone and one Garmin / Wahoo / etc style bike computer, which seems more likely. Phones make pretty poor always-on, always-max-screen-brightness bike computers.

minnesotabob

Oh, I see. That sounds hard for me, not knowing the specific Bluetooth profile required by those special-purpose bike computers. Also, the phone serving as the sensor is another always-on device that probably would use a lot of battery if used over an extended period.

fourfa

always-on Bluetooth, particularly BLE, is a tiny fraction of the power needed to run the screen backlight on full. Coin cell powered ANT+ / BLE cadence sensors run for many years on a 2032. Turn your screen on full power, disable auto sleep, how long will it run on the huge 4000+mAh phone battery? No more than 4-6 hours I'd bet.

Seattle Forrest

A Garmin or Apple watch would be able to display a number from a phone too.

But cadence sensors are cheap. Unless the reliability is dead on, I think a lot of people would rather spend $30 on a dedicated device they'll be able to use for years.

bikebikebike

Second on Magene from ebay, great but slow ship @$~15, BT or ANT+ and will do cadence OR speed. Needs bike computer or phone display.
Metronome is ~$10 and helps you pace, needs no display, attaches easily with cheap phone mount.
All the 0ring mounted stuff is prone to fall off , so cheap is the way to go
Wired sensor / computer is pretty workable, too.
~$150 ante to get you into the bike computer/GPS game, but that really is the way to do it, as a tool you will really be using.