I have completed quite a lot of bike Segments in my local area (over 5,000) and I'm quite familiar with the Segment leaderboards. If I attempt a new Segment I often look at the leaderboard and see familiar names of keen local cyclists. If I see a name I don't know or a big performance gap between the top 2 on the leaderboard I may look at the Activity of the KOM-holder in case of anomalies - if I see obvious use of a vehicle (such an Activity mostly at 10 mph followed by stationary for 5 mins followed by the last mile at 50 mph) then I may comment on the Activity to request the athlete trim their data. If there's no response I may flag the Activity as "in a vehicle" in an effort to maintain integrity of the leaderboards.
Today I saw something strange - I tried a few new Segments and saw a new name who had the KOM for about 4 of them. Their profile was "open" and I could see they had only done 2 Activities (on consecutive days in 2019). For the relevant Activity with the KOMs the average speed was 19.9 mph and the max speed was 16.3 mph - I've seen average speed higher than max on individual Segments if the athlete didn't complete the whole Segment, but I've never seen this for a whole Activity (anyone have an explanation ?). The other thing that is very strange is that in an Activity of about 40 minutes the speed was in a very narrow range of 19 to 21 mph - it didn't go out of this range for sharp bends, junctions, changes from smooth tarmac to rough gravel, uphill at 3% or downhill at 3%. Has anyone else seen anything similar ? My first thought is that they were on an E-bike limited to 20 mph but I don't want to flag their Activity unless it can be proved beyond doubt. As they haven't been active on Strava for 3 years I don't expect any response to a message. One of their "KOMs" is about 20% faster than the 2nd place (of about 300 people).
Any suggestions ?