Distance variations in group events?

I start riding in a group event when everyone else does and try and stay in the main blob. If I am ahead of the red fence or find myself in a break-away group, I immediately slow down to get back into the group. However, as the ride progresses, I see my distance travelled is slightly more than some of the riders I have been riding with. By the end of a 20km ride I have often done 0.5-1km more than the route said it would be. What am I doing wrong?

You’re not doing anything wrong. No-one seems to know why this happens to some users.

You’re definitely not doing anything wrong.

My understanding is that this comes down to whether or not an event is time-based or distance-based, combined with how Zwift calculates/displays distance in each case.

If an event is based on distance, during the event, Zwift will report distance for all riders via the main dashboard at top center of the screen based on a common center line down the route so that the event ends at the planned distance for all riders; however, Zwift is still calculating actual distance traveled by your rider (including side-to-side movement) - that distance is what you see after the event ends, and accounts for the difference between the event plan and the actual distance covered by your rider. You can also see the distance creep during the event by comparing the distance in the dashboard with your distance reported in the “riders nearby” list, which reflects your actual distance.

My group (WSR) used to ride 30 km events but switched over to 1-hour events (we tend to avg. 30 kph, anyway) to eliminate this discrepancy - during time-based events, the dashboard distance and “riders nearby” distance is consistent for each rider.

Hope that helps explain the issue!

I’ve seen plenty of time-based events with slightly different distances per user.

Right, because each rider’s distance is being displayed according to Zwift’s calculated distance during a time-based event. The only difference in how Zwift displays distance occurs in distance-based events in which the rider list shows the individual rider distances, where the dashboard at top center shows the center line distance required so that the event ends as planned.

It’s a Zwift data display issue - all individual rider distances are calculated the same way behind the scenes.

Or to put it another way: during a time-based event, all riders will have ridden slightly different distances while having ridden for the same amount of time. During a distance-based event, all riders will have ridden slightly different distances which, during the event, are displayed by the dashboard as the center line distance.