Sunday, 2 February 2014

Surviving the Winter: NordicTrack GXR 4.2 Review

UPDATE (16th February 2014): All is fixed and working!!! I'll post a new review and an iFit review shortly...
After banging my head against what appeared to be the usual menu-card-driven first-line type of customer support that many for a couple of months I got through to the-man-who-can! The first line guys had suggested swapping parts to be fair, but without success and we'd clearly go to the end of their ability. So after causing a little bit of fuss I got through to the next level of support and, after some initial investigation it was agreed my machine was faulty, then the same fault was identified on a stock version of the bike! More investigation and a surprisingly simple fix - a simple sensor repositioning within the machine has cured everything!!! Two sensors next to each other were interfering, moved apart they behave..... Easy!


I don't have a local night ride route that isn't car-infested so during the weekday winter evenings I don't usually get any exercise in. I've noticed my weight increasing and it's getting harder and harder to shift it. So this winter I had a plan! Early on I bought a rowing machine and at the start of December, I added a high-end exercise bike to the 'stable'. Since then I've been doing more-or-less 30 minutes on each machine each evening. And it's working - I'm down 7.5kg (16.5pounds) from my peak last Autumn.

As I only ride recumbent I didn't really want to go upright for a stationary bike so I went for the NordicTrack GXR4.2. With a 9kg flywheel, 22 resistance settings and the ability to use standard road bike pedals and shoes it seemed a well balanced specification. It's a bit of a beast but that does at least mean it doesn't move in use!

The Good - the iFit feature has been amazing - I'm that impressed I'll do another post covering it in more detail. Basically it lets you plot a route on Google Maps, download the ride profile to the bike, ride the route with the resistance relatively realistically varying and, with the addition of a tablet computer, you get almost-realtime StreetView images of the route. More in a later post.

The Bad - the promised heart rate feature appears to be fake!

The Ugly - customer support, after initially swapping out parts, is now telling me that what I've got is as they intended and tough luck....

So... the full story...

I bought the machine from online retailer Sweatband, who were great - machine ordered, next day delivery. Couldn't have been better. The Courier separated the two parcels during shipping; the machine and the iFit plug-in hardware, but as it took an evening to get the machine assembled and working this was no problem.

So, up and running, the bike comes with heart rate sensor handles. I've used these in the gym so had no worries about them. But on this bike they just don't work. The instructions said to hold the handles for 15 seconds to give it time for the reading to settle. I've been doing 30 minute training rides and have tried hands on the handles for the duration. The problem is no matter what I've done the heart rate displayed on the screen is always just 10x the current speed! I could make that same guess myself without having a display for the purpose!!!

The manual instructed that in the case of any queries/questions/problems to go direct to Icon, the European distributor. They supplied a Polar chest strap - removing the need to hold the handles. The result - no change - the displayed pulse rate is still ALWAYS 10x the current speed...!

The iFit equipment logs data - here is a 30 minute log of speed and heart rate. Now I'd kind of roughly expect heart rate to pick up from rest over a few minutes and then kind of track effort, but as this graph clearly shows - heart rate is almost exactly 1-to-1 tracking speed... The session is steady rate effort - the speed variation is purely from me as I've adjusted my position, got tired, realised I'm slowing, etc.

Next Icon suggested replacing the Console - the main computer. They suggested this on 23rd December and, what with the holiday disruption, the replacement arrived on the 20th January. The results are the same...

This week I've invested in a Garmin heart rate strap and have made a video showing the GXR display and the Garmin side-by-side.

The video shows the pulse rate on the GXR (the figure in the lower centre of the blue screen, keeps alternating with calories display):
* The two readings more or less agreeing at the start.
* As I accelerate the GXR shows pulse tracking speed - immediately jumping from 122 to 141 when speed increases from 12 to 14mph whereas the Garmin takes time to climb up to 120bpm.
* This is repeated for 16mph - and a jump to 160bpm on the GXR.
* And again for 19mph - 197bpm on the GXR with the Garmin still at 144bpm - A VERY significant error.
* A demonstration of deliberately putting the pulse rate at 145bpm is then achieved by simply accelerating to 14mph.

Further testing at different resistance settings shows this 10x speed relationship to remain constant - so even when the machine is set to simulate a hard 12% hillclimb and I manage to maintain a 12mph speed (working very hard), the display 'claims' a low pulse rate of 120bpm where as I'm actually pretty much at my limit.

The GXR is clearly 'Guessing' the pulse rate based on speed - it is not using any sensors at all despite the manufacturer's claim - and the displayed figure is so inaccurate it makes a farce of the manufacturer's claim of being able to use the reading to keep within heart rate training bands.

I've now received emails from both Icon and from NordicTrack themselves 'explaining' this behaviour...

"The heart rate monitor is not a medical device. Various factors, including the user’s movement, may affect the accuracy of heart rate readings. The heart rate monitor is intended only as an exercise aid in determining
heart rate trends in general.

"For the most accurate heart rate reading, please stop pedaling, then hold the contacts for at least 15 seconds. Are you doing so? If not, please do so. You may even want to take three consecutive readings and take the average so as to ensure accuracy. Also the sensors seem to work best when the palms are dry"

I've NEVER encountered any gym equipment that requires the user to stop for the best part of a minute to take their pulse to ensure they're training within their target band - and I'm pretty sure by the third reading my pulse rate will be heading rapidly back toward my resting pulse rate!!!

And this advice is despite the machine 'guessing' my heart rate without me even needing to touch the sensors or wear the chest strap!

This is clearly a dangerous situation - with the machine significantly over reading I'm able to exercise under the impression I'm preparing myself for a much higher work rate than I'm actually achieving. Planning real world activity based on this information and overexerting myself believing I'm sufficiently trained could have serious consequences.

Basically NordicTrack appear to have behaved fraudulently as I have demonstrated above that the equipment I have simply does NOT even attempt to read the user's heart rate. I have not yet been able to establish if this is due to this example of their equipment being faulty, or if the GXR4.2 series machines don't work as advertised.

I intend to offer NordicTrack/Icon the opportunity to comment on this blog and, if the issue can't be addressed, I will refer the matter to Trading Standards.


  1. Icon UK and I seem to be in agreement the bike hardware is probably faulty... possible interference in the wiring harness... They've duplicated the fault on a duplicate bike at their offices. Waiting to find out what the plan is to fix mine...

  2. I also have the GXR 4.2 the heart rate monitor etc. doesn't bother me. Within the last year since purchasing it, the pedal bearings failed, engineer replaced them, on inspection they were rusty and no sign of grease at all, 4 months later it felt as the belt was slipping and making a grinding noise, they replaced the bike without problem, unfortunately they wouldn't extend the warranty, 2 months later the bearings have failed yet again on the new bike,
    seems as though it is a reoccurring fault, emailed them this morning and now waiting for a response.

    1. I use my own pedals so haven't put any miles on 'theirs'... At least they're threaded for standard road/mtb pedals (not something proprietary) if you need to source your own replacement.
      I have had to tighten the belt - instructions are in the manual. I found it was slipping on the steeper sections of some of the rides I downloaded. Seems a bit heavy on the 'easy' bits now but no slip.
      Over the summer I've been putting more miles on a T14.2 treadmill that I was tempted to buy after being impressed with the iFit stuff.