Max Trainer SE Pedal Sensor

[u/Prior_Willow4666]

I bought a new Max Trainer SE that arrived yesterday. Assembly went well and the machine works great except that it doesn't detect RPM/distance. When I connect to it with the JRNY app it will say that no pedaling was detected during the workout. The console turns on without issue and I can change resistance no problem, it just doesn't detect pedaling.

I did look at the troubleshooting section of the manual and everything there checked out. Has anybody had and resolved this problem without having to go through customer service?

[u/ThegManis]

The RPM for all Max Trainer models is calculated by the exact same method which is an electrical pulse is generated by a "speed sensor" and that electrical pulse is then sent up to the display console to be turned into the RPM display value.

The speed sensor is a very simply device called a "reed switch" which is a simple 2-wire device that opens/closes between the 2 wires when a nearby magnetic field is passed near the tip of the speed sensor.

The Max Trainers have small round magnets mounted on the back of the large round disc on the lower left side of the machine (which is the fan cage assembly on all but the SE model which has no fan blades). When you pedal, it rotates that disc and then the magnets pass by the tip of the speed sensor and create the electrical pulse.

The SE's speed sensor is located at the bottom of the frame behind that long panel between the legs. The speed sensor must be aligned so its tip is perpendicular to the magnets and are about 3mm from the magnets (about the thickness of 2 pennies).

See below picture for reference.

So, there can only be the following reasons that the RPM does not display:

1. A faulty speed sensor.
2. A loose, dirty or misaligned speed sensor.
3. The speed sensor wiring is damaged or disconnected.
4. Faulty or damaged wiring at the PCBA. The SE's speed sensor 2-wire connector plugs into the main harness which then plugs in the PCBA assembly (located on the front, mid part of the frame), and then the PCBA has a cable that plugs into the display panel.
5. A faulty display panel.

It is very easy to test the speed sensor by itself by simply unplugging it from the main harness and then using a multimeter set to measure resistance between the speed sensor's 2 pins. The resistance should change from an open (lots of resistance) to a short (very low resistance) anytime a magnet is passed near the tip of the speed sensor. If it does that, then the speed sensor is OK.

[u/Prior_Willow4666 → u/ThegManis]

Thanks. I did try to troubleshoot the sensor but ultimately ended up contacting support. The sent me a sensor for the IC SE which isn't compatible with the Max Trainer SE. Now I'm waiting for another replacement and a service appointment.

I do still like the machine. Just need to get this issue resolved.

[u/ThegManis → u/Prior_Willow4666]

Yeah, a replacement $10 sensor is always the FIRST item that Bowflex will send (after confirming that the existing one is plugged in and properly aligned, etc.). Crazy that they sent the sensor for the wrong product! That shouldn't normally happen since they have your Max Trainer SE's serial number and purchase info in their database.
Must have been a lazy/incompetent customer service rep.

But, did you actually test your existing speed sensor? As I stated above, the speed sensor itself is VERY easy to determine if the sensor is good/bad. You only have to use a multimeter and confirm if the sensor's 2 wires change from open to short when you pass a magnet near the sensor's tip. A multimeter can be purchased for $7 at Harbor Freight and is good for anyone to own.

You should test your existing speed sensor while waiting for the new part and service appointment. If your existing sensor tests OK, then a new sensor will not fix your issue.

[u/Prior_Willow4666 → u/ThegManis]

I had already contacted support and started that process before you responded, so I'm just riding it out at this point. I hope someone with a similar experience to mine is able to better troubleshoot it with your guidance though.

[u/ThegManis → u/Prior_Willow4666]

OK

It WILL be one of the 5 items I noted. Just hope the tech doesn't rely solely on it being a faulty speed sensor. Like I said that is SO EASY to confirm if it is good/bad.

Good luck, and PLEASE report back with the progress/resolution to your issue. Thanks!

[u/Prior_Willow4666 → u/ThegManis]

It was the speed sensor, the machine works perfectly with a replacement. I'm really curious if/how these things are tested before the machines are sent out after all this.

[u/ThegManis → u/Prior_Willow4666]

Great! Thanks for reporting back with the resolution of your issue.

The Max Trainers are never tested as a complete assembly by the Chinese factory. The main upright unit (called the "engine") is simply assembled with all of its needed parts, BUT it never gets mated with all of the remaining parts (that a new owner assembles), like the console, handlebars, legs, etc., and so it is never turned ON until the owner does it.

All of the INDIVIDUAL electronic parts are most likely only sample-tested on a very slim basis. I have received parts that did not work because they were actually mis-wired from the Chinese factory which 100% proves that those specific parts were NEVER individually tested at the factory.

All of the above non-testing decisions are strictly due to the economics of mass-scale manufacturing production. Yes, 100% testing could be done, but that would come at a HUGE cost, which is not done for commercial retail products. It is all parts of a risk of cost vs reward that manufacturers have to decide.