Minimum grade setting for smart trainers

It would be nice if there were an enhancement to the trainer difficulty that would allow setting a floor on the simulated grade. For example, I would like to set the minimum grade set in my KICKR to 1% so that I can still generate good power on the downhills. This would give me the option of keeping my power up consistently going downhill while still getting the simulated grade when going uphill. Right now, if I want to put in long efforts without breaks, I would have to turn off trainer difficulty which would mean that I lose the uphill simulation too.

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An issue with this is that you would instantly PR all of your downhills, and it could potentially be used as a crutch to win races/segments?

I have a kickr too, and it’s annoying when the guy next to you on the not-smart trainer goes zooming by on the downhill while you frantically shift and sprint to keep up.  However,if you’re not on the same grade as the others on the track, then the watts/kg ceases to be an even comparison (I suppose you could do w/kg/grade, but it’s a bit weird.)

Remember that there are two different grades we’re talking about here. There’s the grade that’s used in the simulation to convert watts to speed and the grade used by the KICKR to determine how much resistance to apply. The former is always the same for all riders. It’s the latter that would be affected by any trainer difficulty setting.

I know that feel Mark.  First few rides with someone who wasn’t on a Kickr blew major gaps on downhills.

Hi Aaron yeah it’s a little annoying at times.  I suppose this really begs the question though – how much is this a game, or is it a training aid, or is it trying to be “the real thing”?

I think Christian is certainly allowed to want to use Zwift as a training aid – it’s a great way to ride for an hour without traffic lights, cars, potholes, etc.

If it’s supposed to be as close as possible to “the real thing”, then there’s gotta be a way to keep the competition realistic (I think of games like Gran Turismo which try to model the physics as accurately as possible  - yes you can upgrade the car, but the physics still applies).  Zwift leans this way in my mind as it records fake GPS coordinates of a real place to Strava, and my Kickr is following the grade based upon my weight etc.  So, if they ever do a Zwift version of Alpe d;Huez or something, I would be stoked, but all the Zwift weight-cheaters etc would take the PRs from real GC racers, and that’s not cool either.  I wonder how that’ll be handled?

If it’s supposed to be a game, then that’s cool too.  I can see them leaning this way as well with the drafting and featherweight bonuses etc that obviously make it less real.  If they are going this way, then they need better rubberbanding to catch the non-smart trainer zoomers and the guys like Christian who just want to use it as a training aid (again, perfectly valid!).  Then it would be less frustrating when you get on and all the Aussies and French are asleep (for some reason those guys beat me all the time with valid power meters:)) and you feel like you have a chance at a jersey – but it’s dashed by some muppet pulling 10 W/KG around the whole track.

Anyhow, I suppose I’ve given up on the competition aspect unless someone else is on a power meter smart trainer like me and also is in the same W/Kg – then it’s cool to see if I can hang.  Otherwise it’s just kinda going around by yourself.  I hope they decide what the goal of Zwift is, though, as it seems a bit confused at the moment.

I think you misunderstand my position. I am very interested in competition in Zwift. Applying a minimum grade just levels out the playing field a bit so those with smart trainers aren’t always dropped going downhill because those on basic trainers can put out the same watts on any grade.

Note that I’m talking about mass start racing (such as the Tuesday and Thursday training races on Zwift), not time trials like the various leaderboards. In this context it’s important to balance the realism against preserving the ability of riders on different equipment to compete fairly against each other.

In any case, adjusting the trainer grade doesn’t make you work any less hard, it’s just the speed the trainer is spinning that changes.


HI Christian,

I see what you’re saying, apologies for the misunderstanding – on the mass start races, you are looking for a way to even the playing field by allowing us kickr guys to have a chance on the downhills… 

In addition to giving us some more resistance, another way might be to subtract watts off the guys who don’t have smart trainers.  There’s gotta be a calculation that can be done based on your weight so that it doesn’t let you get over a certain speed that’s realistic with common gear ratios etc…


I think changing the wattage applied is dangerous since you would want the record of the power you exerted to be accurate. It also seems unfair to let someone do work that has no effect since it would increase their fatigue.

I think if everybody is able to put out the wattage downhill, there will be no incentive to attack on the downhill and the end result is people will coast or soft pedal going downhill as they would in real life.

If the issue is getting spun out on the downhill sections I think you will find that adjusting down the percent resistance slider smooths out things a bit.  As a result you do less shifting and it is easier to grab some chain tension downhill.  I would try this because I think it will accomplish what you are after.

Game vs simulation vs training: All I know for sure is that madness lies in the path of simulation.  I’ve made careful efforts over the years using the software that comes with my CompuTrainer to match virtual terrain to real world speeds by adjusting my weight and drag coefficient.  I’m still off by 5% and can’t get it much better.

I’m just one person and geeky enough to try and care.  Throw in 50+ people who just want to ride and kill the mind-numbing trainer experience and abandon all hope of achieving simulation nirvana.

I think you can have great training while treating it as a game.  Outdoor riding is a game, after all.  I’m not riding the bike to pick up groceries 99% of the time.

@Duane - that’s exactly what I do right now. I made the feature request because I think it would be nice to have the option to run at 100%, which is pretty much impossible in races because of the downhill issue. I’ve ridden with other software that has this option and it’s a nice compromise between realism and the reality that you’re still on a trainer. At -2% you still get the feeling of spinning on the downhill while still being able to put out power if you want to.

This is still an issue 6 months later. Just how do you stay with a group or a bunch in a race with a smart trainer? I really want to know what the optimum setting is as now I am joining into more group rides and races.