Currently I own a wheel on bike trainer, the Tacx Vortex, now discontinued. The Vortex maximum supported gradient is 7%. Some of the vEveresting rules and recommendations suggests that if the Zwift course is above 7% which Alpe Du Zwift is then you have to use a direct drive trainer such as the Wahoo Kickr or the Tacx Neo, the Neo supports a maximum gradient of 25%. Otherwise with a wheel on trainer you can find a course that provide lesser gradient restrictions such a the Epic KOM, part of the Big Loop course in Watopia.
I am left with some choices here, forego Alpe Du Zwift and do the Epic KOM or upgrade my trainer to a direct drive. The latter option seems to be the option I’m leaning towards as I have been in search of a direct drive trainer for sometime now and I am a huge indoor cyclist and making this investment will make the overall indoor experience so much better and eradicate future trainer restrictions at least for now.
Read more about the vEveresting rules.
Tacx also has an article on this topic.