So it happened that one day I needed a new cadence sensor for my mountain bike.
Firstly, let me say that I love mountain biking but I rarely actually indulge in it and it always ultimately comes down to one simple thing – if I mountain bike I have to drive somewhere to get to a trail.
With my road bike, I can just hop on and ride somewhere easily reaching anything from small ascents to steep long ones, the same for descents, miles of fairly relatively level roads, and any mix and match of the above. I can ride along the water – dams, streams, rivers, big rivers, small ponds, marshy areas, swamps, big ponds, small lakes, or along Lake Ontario itself. I can ride through wilderness areas, parks, rural residential, farmlands, villages, towns, or through a small city. I can ride good blacktop, not-so-good pavement, multi-use trails, a little gravel or dirt, rough roads, smooth roads, new roads, old roads, etc.
What this all comes down to is that I usually don’t mountain bike a lot, even though I really enjoy it, because I have to drive the bike somewhere to reach any sort of trail.
So I decided to get a little bit cheaper cadence sensor since I don’t use the bike all that much, plus I wanted to try something a bit different than I had before. And of course get a chance to write a review on it if I liked it. You can see a couple of other reviews I have done for other cadence sensors I have like the excellent Wahoo Cadence Sensor (click here for my review) or the just okay Scosche RHYTHM cadence and speed sensor (see my review here).
After some research, the one I bought was the CooSpo RPM Cycling Speed and Cadence Sensor. At this time it is just under $30 on Amazon (May 2020 or Year 1 of the COVIDIAN Pandemic).
I decided on this particular one because it had good reviews and I had seen it advertised before, and also because I have another piece of electronics from CooSpo – which makes bike sensors, bike computers, heart rate monitors, and more. The other CooSpo device I own is the combination CooSpo Speed and Cadence sensor which I use on my indoor trainer bike. I didn’t do a review on it but just to go over it quickly – it works great! That one is different than the one I am reviewing here in that that one is BOTH the cadence and speed in one sensor and requires a couple of magnets, I use it on my bike that is mounted on the Ascent Fluid Bike Trainer (my review here). I’ll repeat it – that one works great but I didn’t need both the speed and cadence sensor for my mountain bike nor did I want to use magnets or extra parts that might get hit while MTB’ing.
So the one that I am reviewing is the CooSpo RPM Cycling Speed and Cadence Sensor (BK467) and unlike the one I mentioned above is ONLY a cadence sensor or a speed sensor and can not be used for both at the same time.
The sensor is packaged well, with a nice design on the box incorporating icons showing that the sensor is ANT+, Bluetooth, IP67 water resistant and dust-proof (you can drop it in water up to a meter deep but don’t let it sit submerged for a long time), and that it is either speed or cadence. You can see the cool little bike gear design on the front of the sensor itself through the little plastic window in the box. So all in all, a really nice professional packaging despite the cheap price.
There is a simple manual, written just fine and in two languages; the sensor itself is 46 grams for you weight weenies out there ;), and size is 1.65”x1.33”x0.47”. Included are two rubber protective pads with nubs that fit into the back of the sensor. One pad is for use on the crank when the sensor is configured for cadence and one for use on the hub when it is configured as a speed sensor. Also in the box include two pairs of different sized rubber-band sort of attachments, very similar to what you see on other sensors and bike computers. In fact, these seem to be the same sizes as ones from other devices in case you need to do any replacements.
It also has a one year warranty from CooSpo.
In the middle of the nubs of both attachment points for the rubber bands is a little indentation that allows you to zip-tie it on instead of using a rubber band. Unlike some other sensors I have used there is only one slot in the middle for a zip-tie here instead of a place for two, but what I did was used the rubber bands AND zip-tied it in its final position. So if one or the other ever breaks someday there is the other attachment method in place as backup. I think this is especially good while mountain biking as you never know what will hit, swipe, or smash into any particular piece of the bike.
As per the instructions you open up the back with a coin, the same method as many other sensors of this type use. Inside you will find a battery (standard CR2032 – again; pretty standard) and a plastic shield used to insulate the battery so the sensor isn’t using battery power while being shipped. Pull that plastic shield out.
The battery fits into the cover itself and the cover loosely containing the battery is slipped back into the sensor body and tightened with the coin – a very short turn of only a few degrees locks it in fully.
At this point, a quick look at the front will show which mode the sensor is in – a red light for speed, and a blue light for cadence. The light doesn’t stay on all of the time but will flash when it is activated.
To switch from cadence to speed or vice versa open the battery door and pull the door and battery out, and then put the whole thing back in and tighten it back down, again – only a short turn does it. The interruption in power toggles between the two modes. It’s quick and relatively easy to switch back and forth. Again – red light is speed, blue is cadence.
Taking a look at the battery door and where it screws into the sensor it seems to me to have the standard rubber seal and fits the sensor body snugly for a good water-resistant and dust-proof seal. We will see as I use it and if there are any issues I will update this post at that point. But so far so good; including some muddy rides that I have done.
Of course, this water resistance is especially important on a mountain bike as the crank is going to get wet and muddy sometimes, and well – there have been times when my crank has gotten totally dunked underwater or under-muck, for a few moments. This sensor should also be water-resistant if you are riding in rainy conditions too, as well as snow. But not if you store your bike underwater of course…
Firstly I tried this as a speed sensor. The hubs on my mountain bike are not super-beefy but pretty standard, yet it still took a little finagling to get the largest rubber-band around the front hub. Which is what you want – you certainly don’t want it loose or jiggly. And it definitely is not.
The rubbery pad that goes on the back of the sensor helps to keep the sensor securely in place and I would trust this just fine, I believe. Though of course over time, years likely; you want to do periodic checks of this rubber-band and replace it if it ever gets old and/or just use a zip-tie. I didn’t try this but I am wondering if the two of the smaller bands could be put on over each set of nubs – for security purposes. Or just use zip-ties.
The sensor can go on either the front or back hub, maybe depending on the size of the hub but likely you’ll want to go with the front.
For an initial test I used the Wahoo Fitness App and my Samsung Galaxy S10e (which has ANT+ as well as Bluetooth), even though I wouldn’t be using my phone for logging my rides on a permanent basis; the phone makes for an easy diagnostic test and tool.
A quick scan with the app on the phone showed the sensor showing up right away on both ANT+ and Bluetooth. It paired quickly in the Wahoo app (pair this sensor in the app, not through the phone’s Bluetooth) and a quick ride around the yard showed it working just fine. I tried both ANT+ and Bluetooth and both seemed to work fine, though I prefer ANT+.
In most apps and devices you will either need to enter the correct tire size or, if the device has an automatic setting, let that determine it and then double-check the automatic settings by riding a known distance. For manual input, there are multiple places to find proper tire sizes like the one from the immortalized Sheldon Brown’s reference site or this one.
A quick test with a few other apps allowed pairing also. Likely if it pairs to one app it means your phone is capable of it and it will probably work on any other app that will pair to an external sensor.
Temporarily pairing it to my Garmin Edge 520 Plus worked just as easily.
What else can I say about using it as a speed sensor? It was quick and easy to pair and it worked perfectly. Since I am not using this as a speed sensor long-term I can’t speak to anything past a quick test in this mode.
Moving on to switching to cadence mode – again; just pull the battery/battery door and re-insert it. A check of the LED on the front now shows blue and it is now in cadence tracking mode. If not pull it again and re-install.
The flat pad for the back goes on the sensor for cadence mode, and again the pad and the rubber-band (one of the smaller ones this time on my bike crank) attach it to the bike. With mine, the attachment location was about the middle of the crank, as there is a depression on the crank closer to the bike on the inner side that wasn’t conducive to the attachment. Somewhere near the middle is going to be the best and most accurate, too far in either direction seems to throw off accuracy.
The sensor isn’t very thick but it is possible with a very close crank arm there would not be enough clearance. It is maybe a bit thicker than some other sensors but still relatively thin.
I tested the attachment with the rubber band for a while but eventually added a zip-tie around the whole thing too. Don’t get me wrong; the rubber band was very secure at that point but rubber/plastic does deteriorate over time.
And again – it was an easy process to pair the sensor with either ANT+ or Bluetooth, to the Wahoo Fitness App on the phone. There is no size adjustment or anything like that for cadence.
As I mentioned above this needs no magnet as there are internal accelerometers – which are motion-sensing sensors – that measure the rotation of the crank arm it is attached to. It is quite accurate and this sensor seemed to be as accurate more expensive ones, a bit more a few paragraphs down.
Next, I tried my Garmin Vivoactive 3 Music watch (see my review of this watch here), and the pair once again went quickly and smoothly with a quick spin of the crank to bring the CooSpo Sensor out of a sleep mode. The name displayed “Sp/Cad” but it picked up the correct mode that the sensor was configured for, which in this instance was cadence.
The Edge found it and I was able to rename it in the Edge sensor settings screen, which is nice as I have several bikes and sensors on each.
For a further test, I mounted this sensor on my road bike and compared it to the Wahoo Cadence Sensor (see my review here) by syncing the CooSpo to the Wahoo app on my phone, then comparing the resulting chart with the one from my Wahoo via Garmin Connect. They were very close, with no drop-outs or crazy highs or lows. Not the most scientific comparison as I just used Photoshop to superimpose one over the other, but for my purposes and likely most people’s it was very accurate.
There didn’t seem to be any noticeable difference between ANT+ and Bluetooth connection and accuracy of recording, though there is always a very tiny lag with any of these sensors I think. This is compatible with Zwift also, in case you are wondering.
Also, one thing that I noticed while testing the sensor with various devices – both with initial pairing as well as when I needed to bring the sensor out of sleep for reconnection – it very quickly powers up from sleep mode and re-connects. Possibly faster than other bike sensors and other ANT+/Bluetooth sensors and devices that I have.
Now for the bad news – as of July 2020 while checking things over I noticed that one of the sides of the tabs that the rubber band goes onto had broken off. It’s still secured with the zip-tie as well as the rubber band for the most part, but it is a concern I guess. The tabs protruding are maybe a bad design versus something like the Wahoo cadence sensor that is a completely different design with the attachment tabs at right angles to where they are on this sensor (and of a totally different type) and so protected by the crank – though in all fairness the Wahoo is JUST a cadence sensor and isn’t double-duty as having the speed sensor capability. A different sort of tab or mount would be required for that sensor to function as both.
So in conclusion I would say that the CooSpo RPM Cycling Speed and Cadence Sensor works very well generally, but I can not give it a full and hearty thumbs up due to the broken tab and possibly the design that allowed it to happen.
It does everything that it should do and well otherwise, and if you are using it as a speed sensor or as a cadence sensor on your road, commuter, touring, etc bike the tab design will likely not be an issue.
But for a mountain bike, the slightly protruding mount tabs that overlap the outside of the crank a bit COULD present a problem at some point.
Perhaps I just had bad luck and a rock or fallen tree caught it just right, and your outcome of using it could be different. I’ll update this post if anything changes but so far with the zip tie it still seems to be secure, with just the rubber band it might not be so.
Otherwise, I would say that if you are looking for a cheap and reliable speed and cadence sensor this might be for you, keeping in mind what you are using it for and my thoughts above.