Trainer Resistance Setting


(K.C. Race3R) #1

Now that Zwift has introduced the variability setting on the game that allows users to set the percentage at something less than 100%, it seems that the percentage chosen by the rider should be displayed on their rider profile. Not that everyone is not honest, but it likely is a good piece of info to displayso that when racing we all can verify that everyone is set to the same gradient realism percentage for fairness sake.  Thanks.  


(Jon Mayfield) #2

Why would it matter what their trainer setting is set to?  They could just as easily be on a classic style trainer without variable resistance.  They still have to put out the same watts to move the guy around the world no matter what the setting is.


(K.C. Race3R) #3

If I understand the trainer setting properly, then it allows a person to chose whether the zwift 10% hill rides as a 10% gradient or a 5% gradient.  If that is right, then there is no doubt that to people of different weights, those gradients make a difference. The lighter rider will have an advantage over the heavier on the steeper gradient.  If that is not the case, then a Zwexplanation as to why this setting exists and what it impacts would be much appreciated. THANKS. 


(Ben Crone) #4

I’m not sure you understand the trainer setting (or physics)… You can think of the trainer setting as the gearing of your bike, an easier setting would be similar to riding a compact. 

Assuming a constant cadence, then a lower trainer setting will result in a lower torque, and as power = torque * cadence (which we’re assuming is constant) power will also decrease with trainer setting.

Zwift uses power to calculate how fast it takes you to get up the climb therefor if you’re cycling at the same cadence then it will take you longer to get up the climb in a lower setting than a higher setting (think back to using compact gearing).

A lighter rider will get up the hill faster than a heavier rider but it has nothing to do with trainer setting, only the fact that it takes less energy (and therefor less power) to haul their ass up the hill.

 


(K.C. Race3R) #5

You are quite right. I did not understand the impact of changing that setting. It seems now that it is all personal preference and there is no shortcut available at all through this setting.  THANKS.   While I have you and because it is on topic, would you expect a smart trainer (one that auto-adjusts cadence) to require the identical effort (all else being equal) to a dumb trainer (like a Wattbike, that does not auto-adjust resistance to simulate hills) to perform identically over a perfectly flat course? Then when we add the hills of Watopia would that change and the smart or the dumb trainers have an advantage either on climbs or descents?  THANKS.  KC


(Stewart G teamWBR) #6

Kev, I use my Computrainer on Zwift and have used it in three modes. ERG when doing intervals at pre-set wattages, slope mode where the power is dictated by my gearing and cadence (maybe similar to the way the Wattbike works) and sim mode. I do prefer sim mode at around 50% grading (as it saves changing gears too much) but if I was wanting to do my fastest time I would choose slope mode. There won’t be much in it but when in sim mode if I am a bit slow in changing gears when going over the top of climbs my watts will drop down quite a bit (as in real life cycling) whereas in slope mode the watts will remain the same if I pedal consistently. On the steep KOM if I am going up at around 4-450W I will drop down to around 200W as it levels out at the second corner and the final one meaning I do lose some speed up it even if I change gears. There is not a lot in it though.


(K.C. Race3R) #7

That is very interesting and JUST what I needed to know!  THANKS. 


(Ben Crone) #8

Assuming infinitely quick gear changes and ignoring any efficiency losses in the gearing, then yes: in theory, to perform identically over a given course (hills or otherwise) would require the same effort regardless of trainer.

This is because the energy (in physics terms) required to carry you over the distance/hill in a given time is the same. 

However, this doesn’t mean to say each effort will ‘feel’ the same to the cyclist. Everyone has there own preferred cadence/torque ratio (to develop a given power) and the smart trainer may force the rider into gears that is away from the preferred ratio (to maintain the power) meaning that the smart trainer feels more difficult than the steady state effort provided by the dumb trainer.


(K.C. Race3R) #9

Thanks again guys for the input here … I have now discovered that my Wattbike that is meant to produce/display 300W given a 6 Fan setting and 80 Cadence was only sending a message of 260W produced to Zwift, my Garmin 1000, and the Wattbike headset … Therefore my power reading and therefore Zwift speed was lower by 13.3% with obvious impact on racing speed and times!  This Wattbike needs to go to Nottingham for servicing!  


(Doug Goglia) #10

Stewart:  how do you change the setting of your Computrainer while using Zwift?

 I didn’t know this was possible.  I typically use Ergvideo rather than Zwift for intervals because it has been difficult to maintain power output on Zwift given the simulated grades.  I keep the trainer setting at 100% but didn’t know you could use Zwift with the CT in erg mode.


(Stewart G teamWBR) #11

Doug, I just do it through TrainerRoad and use trainer relay. This allows you to choose a preset ERG programme or by pressing SLOPE mode which will allow you to change the resistance by gearing or cadence along with fine tuning the slope %. I am sure you can change to ERG on the head unit as well and this will transmit to Zwift. I would need to check the manual again for this though.


(Joost de Vries) #12

Hi Guys,

maybe a little of topic, but you seem to be the guys who can help me with this. I recently bought the new Elite Qubo digital smart B+. When I am riding Zwift it seems that I’m riding faster than I would do on the road with the same effort. Can I correct this with this setting? If so, would I need to slide it to the left or the right :slight_smile:

And maybe is there some standard setting for my type of trainer? Maybe a standard per brand of something like that.

I hear some people about calibrating their trainers, but I didn’t read anything about that in the manual of elite (bad translated manual by the way) and can’t find anything about it on the internet. Or do I have a self calibrating trainer or something like that…

Hoping for your help!


(Joost Knapen) #13

Hi,

Since a week I have the same trainer as Joost de Vries. The Elite Qubo digital smart B+. And I have the same issue. The resistance is by far not enough. Maybe just 50% or even less. On a flat road I almost feel no resistance and I always need to put the bike in one of the highest gears on the trainer. 

Is there a way to calibrate the trainer for Zwift?

Thanks!