Originally Posted by
guachi
On reasonably flat terrain my Zwift speeds and real speeds outside are almost identical once I got my new bike. I did a century on Zwift and outside both on flat courses. My average Watts were within 1 W and the times were less than five minutes apart. So Zwift is realistic (for me) given a suitably aerodynamic bike.
Same for me as long as I ride solo with no drafting from other riders. If I do a group ride on Zwift then it's a lot faster as you would expect riding in a large group. But I did a meet-up ride the other day with a friend of mine, just the two of us with no other Zwifters on the route. I led most of the ride with my friend sitting on my wheel. Average speed was very similar to what I get IRL on similar terrain. I was a little surprised because I'm so used to Zwift speeds being higher. But it's mainly down to all the drafting, presuming you are on an equivalent bike.