Concept2 Forum

Hello,

I recently got a PM5 retrofit kit for my Model C. This included the drive chain assembly + a new PM5.

I will be honest I am a bit sloppy with working with my hands, but after struggling through with it for 4-5 hours I did get the drive chain assembly installed and it has been great. Unfortunately as much as I like the new PM5 I have been having a lot of issues with it.

The PM5 is very erratic about the metrics it displays. When I do a "Just Row" or a timed row and I start rowing the unit displays metrics and then it suddenly just freezes up. The backlight shuts off and the time is frozen even when I am rowing. The strokes per minute is frozen and when it does work it just throws random numbers at me, anywhere from 2 to 102 strokes per minute(as seen by the ergdata app on my phone, the PM5 unit just shows 02 for spm when I am at 102).

I have been talking to support who have been very helpful and sent me a new PM5 unit under warranty replacement. It seemed initially promising but then reverted back to the behavior I mentioned earlier.

I suspect it has something to do with the following part being broken/disconnected. I do see people talking about using a multimeter to measure the resistance.

https://www.concept2.com/product/121

I have 2 questions.
1. How does the PM5 techncially get the metrics from my model C?
2. I have seen some other users comment about using a multimeter to measure the output to make sure things are working, can somebody point me to exactly how I can do this to debug this problem and hopefully fix this problem one of these days.

Thank you!
IPA

indiapaleale wrote: ↑

February 2nd, 2025, 7:08 pm

I have 2 questions.
1. How does the PM5 techncially get the metrics from my model C?
2. I have seen some other users comment about using a multimeter to measure the output to make sure things are working, can somebody point me to exactly how I can do this to debug this problem and hopefully fix this problem one of these days.

1. It uses a magnetic sensor that measures pulses from the magnets on the flywheel. It does some maths on the results and gets acceleration, watts & strokes per minute. It does more maths on that watts number to get stroke rate and pace.

2. It's a coil that senses the magnetic pulses from the flywheel, you can use a multimeter to ensure it has continuity. To do more you'd need an oscilloscope.

Have you upgraded the monitor to the latest publicly available version? That's got to be your first move.

Citroen wrote: ↑

February 3rd, 2025, 4:05 am

1. It uses a magnetic sensor that measures pulses from the magnets on the flywheel. It does some maths on the results and gets acceleration, watts & strokes per minute. It does more maths on that watts number to get stroke rate and pace.

The magnetic sensor is correct, the rest is close but wrong. Pulses report position, from there flywheel speed and acceleration can be calculated, as well as the dragfactor. Based on that, all rowing states (drive, recovery), and linear metrics can be calculated directly (power, average linear velocity, strokerate).

Citroen wrote: ↑

February 3rd, 2025, 4:05 am

2. It's a coil that senses the magnetic pulses from the flywheel, you can use a multimeter to ensure it has continuity. To do more you'd need an oscilloscope.

Can you measure it via a multimeter? When I look at this scope measurement, it is a pretty small peak.

Do a search on here.

You need to set the PM5 monitor to the right version of rower.

The sensors are generally reliable but the wires break or go intermittent at the connector.

The PM5 will throw an error on start up if the sensor is not plugged in or potentially faulty.

Hello Carl et al, thank you for your responses.

I just want to go back to the beginning and explain what work I did to get the problem in hand.

I have a Model C which I purchased in 1996 or so which I have used almost every week since then. In december I purchased a retro fit kit(drive chain kit + PM5). I am not particularly handy but I managed to battle it out and got this replaced and this is where the issue with the new PM5 not receiving any of the metrics since I did the retro-fit replacement work.

At this point I worked with support and they ended up replacing the PM5 unit and I further ended up replacing the Monitor Pickup and Screw Kit—Model A, C. So even with the new unit in place the PM5 just erratically shows numbers.

I did notice one thing, I removed the fan cover removed the flywheel and put it back together in place again. Before I put the fan cover in I rowed earlier I rowed for a few minutes. At this time I did notice the numbers were accurate, when I replaced the fan cover back again and when I rowed the numbers were all over the place. I was getting stroke rates of 234 s/m and at times the timer just stopped when I was rowing.

I really am not sure what's wrong at this point and have resigned to the fact this is what it is and I will just keep rowing without any reliable metrics.

IPA