Elite Realaxiom (connected w/ USB cable)

(Mike Carroll) #141

How old is your trainer?  Mine picked up right away and I don’t have any issues with connectivity (though I do with the absurdly low watt conversion).  However, I have a friend who has a trainer that is about 3 years older than mine (my trainer is about 4 years old now) and his will not connect as a controlled trainer.  I have not had the chance to get over and work on it but my theory is the firmware is too old to be recognized by Zwift (no evidence, just my working theory).  I have not checked to see if Elite offers firmware updates or not.

He has to use the trainer with a separate speed sensor using the realaxiom software running a flat course to control resistance to work with Zwift.

Good luck, and please post if you find a solution.

(Brendon Madden-Smith MEC) #142

Thanks Mike Carroll

I bought my trainer second hand in early 2012, and I think it was 2 years old at that stage. So, it sounds about the same vintage as your friend’s one.

I have been in touch with Elite support, so will ask them about firmware updates. I’ll let you know what they say.

I am also waiting to hear back from Zwift.



(Mike Carroll) #143

Sounds good. His brother had one of the same vintage with the same issue so it seems to be related. Good luck.

(tomas sklarcik) #144

Hi i have problem with RealAxiom Wired connected via USB zwift do not change resisdance during training… in Elite Real this works correctly… I have paired real axiom with zwift and on the main screen zwift said that realaxiom is pair as power meter and also as controlable trainer but not work. Thanks for answer

(Evan Walpole) #145

FYI, the Elite RealAxiom v4 wired USB trainer is not currently supported in Zwift.

My email correspondence with the helpdesk support folks over at Elite trainers tell me that:

“We haven’t given the protocol of the V4 to Zwift as they have not asked us. If they decide to support also this protocol, we are at disposal to give them (they must ask us).”

(Mike Carroll) #146

Jon Mayfield, Back in January you said you were looking to add a power bias adjustment to the wired elite trainers.  Will this be put in or has development here been abandoned.  I was excited a few months ago when I saw the adjustment for resistance in the settings, but while that did indeed change the resistance of the trainer down to no change on hills or up to quite difficult, it does nothing for adjusting the power readings as they adjust up and down with the change in resistance.  When I ride in the elite software or in Zwift using it as a non controlled trainer (I have to run the elite software with a zero percent flat course and use it in Zwift as an uncontrolled trainer) I am normally in the 250-280 watt range and seem to match pretty close to what Strava calculates for my watts and the speed seems to match what I get riding on the road.  I also borrowed a friends Wahoo Kickr which he said pretty much matched his power meter and I was getting about 305 on the two rides I did with that (not sure if it reads different or I was just riding a bit stronger that day).

However, if I use my elite trainer as a smart trainer going all out I get about 95-100 watts.  My rider shows as about 1.3 to 1.5 W/KG which makes me so slow I cannot ride with anyone as they fly by me at 2.5-5 w/kg.  (On the Wahoo I was getting 3-3.5 w/kg).  This makes it painful to ride and of course makes a multi user system useless when I just have to ride on my own anyway.  

I do enjoy Zwift and would like to ride, but have quit twice and am about to do so a third time as I just don’t enjoy it as much riding without the smart trainer yet see no reason to join a multi user program where I can’t interact with others in the smart mode as I am moving so slow.  It gets very frustrating going all out for 45 minutes to see in the end I averaged 13 mph or less.  You stated that once you added the adjustment it would not count as a power meter rider, and I am fine with that as I am not racing and pretty much live in the middle of the leader board on the road and in Zwift (unless using my elite in controlled mode, in which case I am often the last on the leader board by a HUGE margin.

I would like to continue with Zwift, but I do not see my self dropping a $1000 on a new trainer or a power meter when I already have a fully functional (and apparently quite accurate) trainer already.



(Gerrie Delport TeamODZ) #147

Hi Mike,

Sorry to hear that you have such bad luck, I say bad luck because it seem like the Elite Realxiom trainers have some randomness in them some produce high power and other low. That is why Elite has calibration values for each trainer. 

Mine is higher but not as drastic as yours. 

This may seem like a stupid question but I’m going to ask, are your weight correct in Zwift and didn’t you put pounds as Kg. (don’t hit me now I had to ask)

Why don’t you adjust your weight lower than your actual weight until it feels more realistic. Just be aware if you change your weight that in races you could be DQ for cheating.





(Mike Carroll) #148

Yes, my weight is correct.  As I stated, watts/speed seem correct if I use it as a non-controlled trainer and when I tried a friends Wahoo, just not as a controlled trainer.  I did play with the weight a bit out of curiosity.  I weigh in at 173 and dropped the Zwift weight to 90 pounds and did a ride.  It took my w/kg from the 1.4 range up to about 1.6 as I recall, so a slight increase, but still could not hang on the wheel of even the slow riders.  It really only made a difference on the climbs.  Downhills I was a bit slower though not as much as I expected and a very slight difference on the flats. 

I have never done a Zwift race as I can’t even hang with anyone on a social ride, but I guarantee I would not get kicked out for cheating!

(Sean Scott WKG) #149

Hi Guys,

I have a wired axiom and a Max running OSX Sierra.  I tried to pair my trainer with the zwift app and it didnt work. So then I noticed that I needed to install a USB driver.  So I did that, rebooted, and tried to pair again with no success.

Is anyone having success with OSX Sierra?  



(Sean Scott WKG) #150

Evan W.


How do I determine what version of the trainer I have?

(Sean Scott WKG) #151

Ok… I looked at the elite software, and it looks like my trainer is a V4.  Zwift… It would be so awesome if you would add support for this trainer too!

What is the likelihood this would happen? 

(Evan Walpole) #152

I think the only reliable power meter reading you can get from an Elite trainer is the Drivo. Everything is else is ‘calculated’ power value. Other modern Elite trainers are kinda okay once you calibrate them. But for the older wired units, I guess somewhere between Zpower and a Power meter, with upto +/-50 W deviations.

Want accurate power but not a new trainer? Get a used Powertap hub on eBay. I bought mine for $150.

If you have ever dealt with the Elite Support, you might have a bit more sympathy with Zwift as to why they haven’t optimised the older wired trainers. Corresponding with Elite’s customer service team is frustrating experience.

If you have an unsupported Elite Real wired trainers,  then go open a ticket and let Zwift know! Keep this thread alive. And request the same from Elite’s support team and on their forums. Someone is dragging the chain. The wired communications protocol isn’t esoteric or even encrypted. Not much difference between pre/post 2006 Elite wired trainer protocols. Message length differs by a few bytes.

You can actually reverse engineer the serial protocol with a port sniffer and known programmed step resistance values. Did a bit of it this week. Bridged that data to ANT+ FE-C with the help of another kind programmer who shared his Serial-to-ANT+ code with me.

Had a RealAxiom v4 channelling though my PC to output via a ANT+ dongle identifying as a Fitness Equipment Device. Dynamic road slope/grade worked! For about 10 minutes, then my device blew two fuses on the resistance unit. (Wasn’t actually on the bike when it happened, was debugging). So maybe it’s a coincident? Anyway, I’m not releasing the binary until I get my trainer repaired and more bug testing performed.

Another solution and much simpler idea would be to write a serial communications wrapper to make the the Elite device looks like a post ~2006 trainer. Or a Computrainer!

To start reverse engineering unsupported Elite Real wired device communications protocols, start by downloading AxtoTest over at https://elitesrl.zendesk.com/hc/en-us/articles/201999801-Calibration-wired

Download and run this too:

Then run AxtoTest. On the RealAxiom V4, if you only change the Resistance value but not the Elevation value, the trainer resistance doesn’t change. But if you set both Resistance AND Elevation, then the trainer will update the to the new resistance value. Alternatively, use Real.exe and create a custom slope-time or power-time workout. Say a gradient or power ramp test, +1% or +25watts per minute, starting at 0% or 0 watts.

On my  Axiom v4, the byte value of resistance clips out at ~0xEC = ~6% in Real.exe. Grades 6.1% to 12% exact same thing. (The user manual says that the trainer simulates grades up to 12%, hmm…)

Typically 6 bytes. The received message length is of the format:
RCV >> F0 01 28 0D 00 F7

Byte 01: 0xF0 is start byte for the message frame
Byte 02: 0x01 Regular/ordinary trainer operation mode.

Byte 03: CONSOLE BUTTONS: 0x21 = ‘+’
0x02 = ‘-’
0x04 = ‘Left’
0x28 = ‘Right’

(Zwift engineers, if you are reading this, please map the console buttons to turn directions!)

Byte 04: Number of times roller has half rotated in 100ms.
Used to calculate speed… eg
Axiom V4 roller diameter = 39.5mm
Roller circumference = 2*pi*(39.5MM) = 124.09MM.
Rounds per roll event = 0.5.
Distance per roll event = 124.09*0.5 = 0.062045 meters. Speed (m/s) = (0.062045m/100ms) * (int)(0x0D)
= 0.625045 * 13 = 8.13 m/s = 29.25 km/h

Byte 05: ??
Byte 06: 0xF7 = end byte of RCV message frame.

I don’t have a wired cadence sensor or analog 5kHz heart rate strap. Maybe the message frame length is an extra 2 bytes long if they are detected?

For TRANSMIT (PC—>Trainer)

Wake up console / identify unit example:
TRX >> F0 08 28 00 00 F7
RCV << F0 08 50 00

Get console unit serial number example:
TRX >> F0 03 00 00 00 F7
RCV << F0 03 00 15 B2 F7
Bytes 4 & 5 = 0x15B2 = 5554 dec.

Set resistance example
TRX >> F0 01 4D 00 00 F7

Byte 3 = 0x4D = 77 dec ~ 1.5% grade.


Hope that helps. 

(Gerrie Delport TeamODZ) #153

Hi Evan W


That is a very informative post, I was going down that path when Zwft was just supporting wireless trainers, currently they support my Elite Realxiom trainer.

Please keep us up to date with you progress.

did you get a ANT+ powertap hub or did you convert a old wired one to ANT+


(Evan Walpole) #154

Gerald, I got the ANT+ Pro model. And it came with a Mavic wheel and tyre! The trick is to use ‘fat fingers’ search terms in eBay e.g. (powertap, power tap, powartap).

What is everyone’s Elite Real wired trainer versions? I’m curious to know what works and what doesn’t. We don’t want more people buying secondhand used RealAxiom trainers only to find out that they don’t currently work in Zwift. We need a definite list of version numbers. Could everyone on this message thread please contribute your knowledge.

Alternatively if you like riding solo, you can manually input the Richmond and London courses into the Geolocation trainer feature in Real.exe. Turn on 3D Google Maps. It’s like riding around a giant impressionistic Lego representation of the actual world. Very cool/weird.

Unfortunately grades are fixed per 500m on a course in Geolocation rides. I’ve created a Python script that will overcome that limitation. Converts GPX files to TGM files that Real.exe can load. The Strava GPX file of Watopia isn’t so great to look at in Real.exe, it’s just the Zwift course plopped on a random Pacific island. But London and Richmond look hilariously silly. If anyone is interested I’ll link a copy to my Python script.


(Sean Scott WKG) #155


Great info.  I am a software guy too,  and I started digging into the ANT+ protocol and sniffing the serial port as well… in hopes to just write a Serial to Ant+ adapter.  Seemed like too much of a project so I stopped, but you have really made some good progress!  I do have a wired cadence sensor, and if you tell me what you would like me to do, maybe I could send you some data.

I also wrote Elite asking them to sell me an ANT+ controller for my trainer.  They claim its some super huge deal to make such a thing, so it doesnt exist.  ha!

Anyway, I would love to get my real axiom working… but I am really just about to pull the trigger and buy a Kickr.  Keep us informed on your findings!

btw, I believe I have the Real Axiom V4.


(Evan Walpole) #156

Yeah they could create a embedded serial-to-ANT+ device. $1 to make, $100+ to sell. Or just friggin’ publish the serial comms protocols to everyone. But then they wouldn’t be able to sell you a one of their new trainers. 


Program is a bit buggy. Was coded in C#… serial port library quite restrictive. Writing resistance data is fine, but Read data a mess. So speed / cadence / HR / power from trainer disabled for now. Needs to be rewritten in C/C++.

When I tested the program, wasn’t recording any ANT+ packets for later debugging. I don’t know if Zwift send out wind resistance (i.e. for drafting) or alter rolling resistance (when riding over dirt). 

Run the AxtoTest program. Is the message length longer with cadence (extra byte or two)? 

And submit a support ticket with Zwift. The more V4 users petition for trainer support, the faster they will implement it. 

Haha but if you buy a Kickr, I will buy your old Axiom V4 from you. If I had a spare V4 the program would be done by now.

(Evan Walpole) #157

Sean or Gerald, could you guys do a small favour for me?

Don’t know if I also borked my RealAxiom V4 Console Head Unit. Can’t remember if it flashes LEDs or shows up as Device Driver when only plugged into PC (and not Resistance unit).

Could you both disconnect the RJ-45 cable that links the Console Head Unit the Resistance unit. Then connect the USB cable that links Console Head Unit to your PC (switched on).

Does the Console Unit flash any LEDs? Does the computer recognise that there is a device? Not in Zwift of course, but in System Properies or System Report.



(Gerrie Delport TeamODZ) #158

Hi Evan

So I checked my device specs. 

Axiom device: 4.5

Prod. version 5


I also did the test as you asked. 

  1. no wires connected to the head unit, then I connected the USB cable: No Led, no reaction from the Windows pc and noting showed up in device manager.

  2. Connected the RJ-45 no Usb: Head unit led light up green led Flash

  3. RJ-45 is still connected now i connect the USB: Green light stop flashing, Windows PC show device connected  to com 5

(Sean Scott WKG) #159

Yep, I did the same test.  The head unit must be connected to the trainer in order for it to light up and connect to the PC.

(Alain Alphonso) #160

I am planning to buy a used realaxiom wired 2015 model, is it working well ? Does it change resistance automaticly ?