Support for cyclops alu rollers (with resistance) - all data included in post for developers


(Finlay Downham) #1

Hi

I entered a support request and was told to post here.

I’ve provided the attached info to both TrainerRoad and Sufferfest in the past so that their dev’s could add support for Cycleops aluminium rollers, and they were very happy to oblige as all the data they needed was there … so it would be really great if someone at Zwift could do the same to add support for these rollers too.
FYI - I’ve tried using the generic roller profile on zwift but it way overestimates power figures.

Attached are power charts for power vs speeds on each resistance level:
info

About how the rollers operate:

The rollers have a level 0 where no resistance is added (Or no resistance unit is fitted to them).
After engaging the resistance unit by turning the dial, you have levels 1 to 5.
The resistance unit is very much manually operated and an optional extra, so not everyone may have or use them, and changing mid workout is not really something I’d think many people would do.
Trainer road and sufferfest provide virtual power for these rollers based on the attached figures
More info on these rollers/ resistance unit etc can be seen here …
https://www.cycleops.com/product/rollers
Video:


(Lee Downham) #2

Today I quickly tested this for a few minutes at the start of a ride against my quarq power meter - I set zwift on virtual power and used my garmin to record and show actual wattage.

Without being rude, the algorithms in Zwift are utterly useless.

I set the cyclops down to 0 resistance … (with resistance at 1 or more the results were even more crazy)
When pushing low watts, Zwift calculates about half power seen by quarq, and vice verca (higher watts = doubles power) … seems the algorithms are a curve rather than straight (as seen on OP’s graphs)

So when quarq says 80w, zwift says something like 40w
around maybe 100-120w it seems to roughly meet up
above around 140w it starts to go up exponentially, and from memory Zwift pretty much doubles power output at about 170w - 200w but then hit some kind of ceiling as it displayed 400W (whilst I was pushing around 300w on the quarq).

FWIW the max power I was able to get in to the rollers (measured on quarq and recorded on garmin) with resistance level 5 was in the region of 870W at a cadence of 150 rpm … not sure how that stacks up with the lines above, but my weight is 78kg and bike is perhaps just shy of 8kg with 25c tyres.

Hope this is all useful to someone in development who takes it upon themselves sort this … should realistically be a quick fix … instead of curves use straight lines for power and you will be much closer :wink:

The figures in the graph above should fix this … seems like I said the power profile zwift uses is something of an exponential curve rather than a linear resistance between speed and power.