NeoBike - Power reading differences

I don't have a Neo Bike, but I have owned two Neos and two Neo 2 trainers. I also have Assioma Duo pedals, owned since my second Neo. Data observations....

First Neo matched second Neo by perceived effort (heart rate vs power at steady 200W).

Second Neo matched pedals

First Neo 2 measured -8% compared to pedals at all power levels.

Second Neo 2 measures -5% compared to pedals at all power levels.

Pedals measure the power where it is applied by the foot, before any transmission losses. Neos measure power at the hub, after any friction losses between cogs and chain and chain links. I imagine the Neo Bike measures at the same place. It does not seem likely to me that the bike should report higher power than the pedals, certainly not 3-5% higher, even with margin for error.

Are your crank lengths set correctly for the pedals? Have you double checked pedals calibration with a static load of precisely known weight? My guess is that the bike is off, but I don't know if this is likely or common, since I don't have the bike.I just know that the Neo 2 has a reputation for not being accurate. FWIW I only bought the first Neo. The three subsequent models have all been warranty replacements for different problems.

The crossover in power looks really unusual. I have some graphs of my own in this thread....

https://forums.garmin.com/sports-fitness/indoor-training/f/tacx-neo-2/251100/tacx-neo-2-power-accuracy

and the difference is quite consistent throughout the power range, with my Neo 2 always reading less than the pedals.

I think you need to contact Garmin support directly about the bike. I've always had good outcomes from support in the UK. Either phone or use online chat if you want a rapid response. I've found email to be very slow with replies.

Apologies - I realised that I had posted a screenshot of an untrimmed ride which completely screwed the graph. The trimmed version shows the charts matching, though transposed, with the Assioma pedals around 4-5% down.

No worries. I saw your post on Facebook too. As others have said, it is unrealistic for the bike to produce higher numbers than the pedals. Since you have Garmin pedals as well as the Garmin bike (and the Assiomas for reference) it would be difficult for Garmin to argue that both bike and pedals are correct. That should help your case for action.

Hi TimGo,

I've just got a new bike and I have the feeling that is mesuring +10%power.  I'm going to borrow a garmin pedals to compare and will let you know.

Did you contact Garmin support regarding this issue in the end?

Best regards

It is a common issue, 3-5% overmeasuring... i have seen only 1-2pcs (maybe from the new version) which was below to a dual bike powermeter (Assiomas), so probably those were (more) accurate. But its design a garbage imho, very sensitive for heat, cadence (the speed of the rear "wheel")...