Garmin 010-12843-00 Speed Sensor 2, Bike Sensor to Monitor Speed, Black

Garmin has once again created a great product. Good seller with quick shipping also.

Connected right away with a strong signal. I use this with a resistance trainer for Zwift and it works perfectly. I bought this to replace a cheap, off-brand sensor that I got bundled with a trainer. I absolutely love the trainer, but the speed sensor had terrible battery life and stopped working after 350 miles. So far so good with this one. I have high hopes. I've had nothing but good experiences with Garmin. I LOVE my 935. It's never let me down during triathlon training and I'm sure this sensor will be no different.

I purchased this as a replacement for the previous version of Garmin speed sensor. Not that the old one is broken, but it needed a magnet attached to a spoke for it to work, so it became inflexible. This one just attaches around the hub is easy to install and move to different bikes/wheels without any tools.Pairing it to a bike computer or watch is also very easy, and it self calibrates for wheel size. Very happy.

Works as advertised.

I use this on a 29" mountain bike rear tire for indoor winter training on a bike trainer.Pro, Con, and Resolution.Pros: Reports a consistent speed that I believe feels appropriate to my road riding. There is no weird highs/lows. Paired quickly with Garmin 645 and Garmin Connect.Cons: You can find all over the web that if you spin the hub it does not wake up and I can agree as I wanted to throw it against the basement wall and was ready to return it. I had to keep removing the device, then remove the battery and put it back in, and then reattach the device.Resolution: What I found out...I was so very frustrated when it would turn on when I moved the bike on the floor (two rotations) and it would NEVER turn on when it was on the trainer. When I would disengage the tension on the wheel it would work when it spun free.What I realize and highly believe is with knobby tires on a mountain bike it generate lots of vibration in the wheel that must mess with what I assume is the accelerometer. I think it is looking for a specific curve and it gets lost in the vibration.Still is not a good thing to disable and then reenable the tension to get it to work but at least I know and do not need to mess with the battery.Wish: If Garmin would be listening...a press to turn on would be great to avoid this whole issue of not waking up. Or just sense vibration not rotation because there should be a way to firmware update that.

This is my second Speed Sensor 2 from Amazon. First unit purchased last year. Sold and shipped via Amazon. Sync'd with Gamin Connect app. Upgraded firmware. Using the sensor with a 3rd party cycling computer. Zero issues.The second unit I purchased was sold by a 3rd party vendor and shipped by Amazon. I had all sorts of problems with this unit.Problem #1. The unit came up on Garmin Connect app with an odd name. The correct name should be Speed Sensor 2. This unit came up as BSG 2 SPD(?). (I'm not 100% certain what the name was. The unit has already been returned to Amazon.)Problem #2. I could not update the firmware on the sensor. Tried multiple times, got multiple failures.Problem #3. I tried sync'ing the sensor to my cycling computer and it would sporadically send speed info.I have this weird feeling that this is some sort of counterfeit product. Problem #1 and #2 are dead giveaways for counterfeit products.I wrote this review to alert potential buyer to be on the lookout for counterfeit products.My overall rating is based on the legit Speed Sensor I purchased last year. It really works well.

If measured wheel calibration is correct,,, speed and distances while mountain biking in wooded area should be exact. Wooded areas without speed sensor will give incorrect GPS readings.

I bought this with a complete disregard for all the negative reviews. Took some effort to get it to wake up and removed the battery. Nothing keeping the battery from making contact. Who knows how long that battery has been active.After a bit of frustration I was able to pair the sensor to my app/watch. Took it for some test rides. It worked just fine. Then of course when I take it out for a trail ride it failed to connect, it failed to turn on and flash the green light. I got nothing and going into the app it showed I had nothing paired for a sensor. Tried once again to go through the process but the sensor just wasn’t turning on. No green light flashing, just dead. It’s a pain to put on and take off and if I have to do that to remove the battery just to get it to wake up… not worth the hassle. Really Garmin, what’s the point of selling these if you keep disappointing your customers and get endless returns. My Garmin watch fails to track my rides accurately, that’s the only reason I bought the speed sensor. I’m just gonna use other apps for now on.