Trainer doping?



Sorry if this has been asked before, i’m only a level 5 so Zwift is all pretty new to me. 

I’m using a Tacx Flux trainer and was joined by a buddy the other night on a Bkool smart go. Now i’m usually the one waiting at the top of the hills or the one doing the towing in a head wind with this guy out in the real world but on Zwift it was like trying to follow Contador on a good day! Once he got out in front i just couldn’t reign him in, and on the climbs he was gone? Watts is watts…right??

Yes, watts is watts, as you say. But unfortunately, not all trainers are created equally. As a former owner of both a Tacx Vortex (piece of rubbish imo) and a BKool Pro, I did find the accuracy of both varied dramatically. At one point I got a replacement Tacx Vortex (due to the aforementioned rubbish nature of the trainer) and found that it gave me completely different power figure to the previous trainer.

When I moved to the BKool, my FTP took a nose dive. It was much more difficult, even though “watts is watts”. I can only guess it has to do with the accuracy of the power meter, and the fact that the Vortex you needed to tighten the roller to the wheel.

Now I have got a direct drive trainer (Elite Direto) which claims 2% accuracy (although tests show it to be better than that), and again I noticed my in-game power down on the BKool (but closer to reality now).

So it might have to do with the fact that the BKool is grossly over stating its power, so your friend zooms up the road.

Thanks for that Steven, I was wondering if it might have something to do with the fact that mines a direct drive and his is tyre resistance, good to hear from someone that has tried and tested a few formats.

The difference in speed you’re running into could be caused by a number of factors. Varying levels of accuracy between the two trainers is a biggie - weight is another.

Andy - I took a look at your account and noticed you’re pairing using ANT+ FE-C. I’m willing to believe that the discrepancy could be due to differences between trainers. All the same, I’m creating a support ticket for you so I can double check your ANT+ signal strength - keep an eye on your inbox!

Steven is bang on. Take zwift races with a pinch of salt as what trainer you use makes a massive difference.

I went from a tacx vortex to a tacx neo and my ftp dropped by 40! which is a massive difference. If i was on my neo id never be able to keep up with myself if i was on the vortex. Obviously the neo is far more accurate and a true representation as to the watts you put out.

The only way you can be assured its as fair as possible is if your all using high end direct drive turbo trainers with a high power accuracy but obviously thats not the case for everyone on zwift races unfortunately.