I am new to Zwift and will be purchasing a Kickr Core soon and my road bike has a 11-40 11 speed rear cassette (I live in the hills and very much a novice).
So should I purchase another 11-40 for my Kickr Core to use with Zwift or go with a 11-28 or 11-32?
It depends on how realistic you want the trainer resistance to feel. If you want it as close to real life as possible, then get the 11-40 cassette and crank the Trainer Difficulty setting to 100%. If you would like some closer ratios, perhaps for racing, then get the 11-28 or 11-32 and you can turn the Trainer Difficulty setting down if you find the resistance too great on steep hills.
I chose to install on my kickr the same size cassette as I ride outdoors! This simplifies any gearing/shifting issues and seems more realistic.
Kickr’s come with an 11 speed cassette, just try the standard one for a while and see what you think.
I haven’t seen any Kickr come with a cassette? My Kickr core definitely didn’t.
I didn’t say Kickr Core.
I think it’s what the additional £300 is for… 
Sorry guys, I am purchasing a Core which does not include the cassette. Sorry I left out that detail. I fixed my OP. I also went ahead and purchased the 11-40 to keep everything consistent for me and my bike.
Lol, now I look stupid… 
If you’re going to use the 11-40 to be consistent with your IRL bike, be sure to also set the difficulty slider to 100%.
That’s completely unnecessary, the difficulty setting is explained here
Setting it to 100 doesn’t make you strong or cool, it just makes you have to shift gears more
Watts are what move you forward on zwift, and Watts are Watts if you are at 100% or 0% difficulty
Difficulty setting actually doesn’t really have anything to do with actual difficulty
Perhaps you should re-read that article, as the difficulty slider DOES change how Zwift operates. With the difficulty slider at 50% a 10% grade feels like a 5% grade. Sure, watts are still watts, and watts are what makes the avatar move, but the OP stated that he bought the same cassette as his road bike so that he would have the same feel on both. So, if he sets the slider at 50% he will clearly be using different gearing in Zwift than IRL. My suggestion was simply to make the Zwift and IRL experiences as similar as possible. Why you feel the need to attack my suggestion is beyond me. I said nothing about the OP trying to be strong or cool, just about trying to get consistency between the two.
I think I found them all. I like this game. Another?
Depending on a riders fitness and the terrain they are used to, setting the slider to 100 could lead them to have an absolutely horrible time on zwift.
Just wanted the OP to not feel pressured to set it to 100%
I’m a flatlander and I tune my difficulty down to around 30-40 percent so I don’t have to shift as much on zwift, different strokes for different folks. Nothing wrong with trying different settings though, find what you enjoy!
Hope I didn’t miss any…
its far better to use a 11-25; and lower your setting to stay on the big ring and dont change. ripping up and down on the front chain ring is not necessary at all.
I went with the 11-40 and with Zwift set at 100% it feels amazingly like the real world and forces me to select similar gearing to real world. That is what I was after.
Personally I want my indoor rides to match real world as much as possible.
