Please add sim mode so my trainer works and so we can specify slope %

It would be really useful if sim mode could be added (or maybe just replace the current resistance mode).

The wattbike atom next gen currently has issues with erg mode (, and without support for sim mode it’s not really possible to use the app (this is wattbike’s fault).

Thanks for the request Joe. If I understand it correctly I think sim mode would be cool too as it would be easier to add slope mode. So +1 could be +1% grade for example…


Hi Alex, I think I understand the difference in the modes now. I’ll link a couple of resources that imho explain it well.

In essence:
RESISTANCE- Fixed brake power (think Shwin Bike etc.) linear power increase with cadence. PROS: Simple to implement. Does not need to be “smart” (like needing to know rider weight/hight/bike) CONS: Does not really feel like riding a bike. Values don’t translate from one trainer to another- 50% brake power on a powerful trainer not the same as on a weaker trainer. Not intuitive (what percent setting in i.e. closest to riding in the flat or say at 7% grade)

SLOPE/SIM- exponential increase in power when going faster. PROS: most realistic ride feel. Speeds/Gearing feel of acceleration should be very close to the real bike. CONS: Needs to be “smart” (know the hight/weight/bike type to compute Crr Cda. Intuitive: Every rider knows what a 7% slope feels like.

LEVEL- exponential increase in power when going faster/spinning faster. PROS: more realistic feel than resistance mode. CONS: values don’t translate from one trainer to another. Not intuitive (what percent setting in i.e. closest to riding in the flat or say at 7% grade)

You are the best!!! :slight_smile: Very nice. Makes absolute sense. I knew resistance was like a break, I did not realize slow was expoential like this.

Oh I see Wahoo points out 4 modes

  • Sim mode and Level mode are different, I had heard (or thought) sim, level and slope are all the same. Looks like I need to do continued research. We have not started working on this yet just having conversations here.

I see Tariq did something too

My pleasure, Alex :slightly_smiling_face:- Now to the unknown:

I’m not sure how FTMS works. To explain: When using the Wahoo app, I need to set weight/bike/hight and the Kicker does the “simulation” with their algorithm- it feels quite realistic to me, imho the “best” mode.

Now I wonder: I assume that i.e. Zwift do “their own thing” to control the trainer (you need to enter riger weight within Zwift). I’m assuming they have their own simulation model to not rely on how different trainers do the simulation, but I’m just guessing here…

Does FTMS allow to tell the trainer “do SIM/SLOPE modes” or would you have to come up with your own simulation model? I’m hoping not :wink: While the math is simple, it’s probably a bit tricky to come up with gain-/ramp up values that work with different trainers…

Yes, I have resources at Tacx and Wahoo to help. I know this is what I heard about FTMS. This is from DCrainmaker’s Neo 2T review.

Tacx actually does support FTMS on all their non-NEO series just fine, but doesn’t do FTMS on the NEO series due to FTMS’s lack of ability to transmit weight information to apps (which is needed for the virtual flywheel in this specific trainer series).

We do 3 protocols FTMS, Neo and Wahoo. So I think we Neo and Wahoo we can use their sim/slope mode but with FTMS yes might be more complicated.

But you are right I will move this stuff to to other thread :slight_smile:

I now realize there are 3 different requests here :slight_smile:

  1. Like zwift’s free-ride mode allow to automatically switch from ERG to free-ride (slope). Also like the tradtional 20-minute FTP test in TR
  2. Create a slope mode that increases “resistance” on target changes like ERG mode
  3. Supporting slope mode in addition to resistance mode (this one)