Power output differences two different setups with Neo 2T

Hi everyone,

I am confused on setting up my powerzones for outside and inside training. I know I am not in the easiest situation as I have two different bike setup. Yet, outside feels way too easy compared to inside.

Inside : I use a low-range bike linked to a Neo 2T for power
Outside ; High end bike with Quarq AXS powermeter

I once put my outside bike on the Neo 2T and found 2 to 5% difference in power measurements. The Quarq being higher than the 2T. The higher the power the higher the difference.

Where I find it hard to understand is that I just did a ramp test recently which has always worked fine for setting up my zones and ended up with a 290W FTP and I have done my first trainings on this value and they seem hard enough or just a bit too hard ? Still to be completely determined.

After McAdie on this I was really tired but went out with my outside bike for recovery and tested myself (I couldn’t resist) on a 7 min slop outside and averaged a not so hard 345W for those 7 minutes. I could have pushed more or longer not 50% let’s be honest but I am confident I could have a 310W FTP outside from an 8 min test. And I was tired from the morning McAdie…

I am not familiar with the roads outside my place here as I just started cycling 4 months ago and so I find it hard to complete a full FTP test outside for 20 min for example.

The thing is I really think the difference in power is huge and I would assume it may be due to : bike quality, power measurement position (spider vs. hub), outside feel… but all this to so much difference ? Seems quite weird. I also heard the Neo 2T might underreport but I am not entirely convinced it does… If I compare my power output outside on the short climbs I have around here with people my weight and all, the outside power seems very accurate compared to all other athletes as I climb as fast with the same weight and same power…

So the problem is I find it hard to really know how to train outside as my zones feel a bit random for it. Apart from finding a way to really FTP test outside I have not had any more ideas to “adjust” the zones…

If anyone had the same issue or have some advice I would be so glad.

Thanks a lot !