Edge 840 speed issue with e-bike

probably you paired your ebike speed sensor to the connect app also (and not just to the Edge itself), delete it

I haven't got the ebike paired to the connect app, only to the edge. The only other app paired to the bike is the specialized app

the speed sensor, i mean. the phantom distance is coming from this issue, if a sensor paired (accidentally) to the connect app directly also

or this extra distance is in the edge? i mean, you know that a trip is 30km but the edge recorded 50km in total? can you share a fit file here in zip format?

The extra distance is in the edge itself. I'll download the fit file. Also, have a look at the speed grafic19718173071_ACTIVITY.fit

Hi Juan, i checked your file, and yes, apprx after 5 1/2 mins, the speed is changed to a fix fake value for the rest of the ride (or until you disconnect, reconnect) and this cause the fake distance also: (yeah, appprx 30.6km this route, not 57km)

= TYPE=5 NAME=record NUMBER=20
--- timestamp=1121326366=2025-07-13T07:32:46Z
--- position_lat=508215755=42.5981525 deg
--- position_long=-107408455=-9.0028727 deg
--- distance=124206=1242.06 m
--- accumulated_power=27988=27988 watts
--- enhanced_speed=1745=6.282 km/h
--- enhanced_altitude=2709=41.8 m
--- grit=37.5=37.5
--- flow=0=0
--- power=0=0 watts
--- ebike_travel_range=1=1 km
--- heart_rate=148=148 bpm
--- cadence=71=71 rpm
--- temperature=21=21 deg.C
--- fractional_cadence=0=0.00 rpm
--- xxx107=1=1
--- ebike_battery_level=68=68 %
--- ebike_assist_mode=1=1
--- xxx137=97=97
--- xxx138=91=91
--- xxx144=148=148
==
= TYPE=5 NAME=record NUMBER=20
--- timestamp=1121326367=2025-07-13T07:32:47Z
--- position_lat=508215554=42.5981356 deg
--- position_long=-107408387=-9.0028670 deg
--- distance=124925=1249.25 m
--- accumulated_power=27988=27988 watts
--- enhanced_speed=7194=25.898 km/h
--- enhanced_altitude=2709=41.8 m
--- grit=37.5=37.5
--- flow=0=0
--- power=0=0 watts
--- ebike_travel_range=1=1 km
--- heart_rate=148=148 bpm
--- cadence=71=71 rpm
--- temperature=21=21 deg.C
--- fractional_cadence=0=0.00 rpm
--- xxx107=1=1
--- ebike_battery_level=68=68 %
--- ebike_assist_mode=1=1
--- xxx137=97=97
--- xxx138=89=89
--- xxx144=148=148
==

aweatherall any idea what can cause it? wrong data from ebike via ANT+? (i dont think that the circumference auto-calibration makes it wrong, the re-calculating is periodically during the ride, isnt it?)

My guess would be that the ebike is sending the wrong data. The ANT traffic would need to be logged to determine that

yeah, i had similar experience with Wahoo HR sensor in the past many years ago, it transmitted weird datas via ANT+ but good via BT. Maybe the dual transmission is the problem in same time, some sensors cant handle it properly but working good if only the one of the protocols is used.

meneillos1980 do a test that you dont pair it to your phone via BT and using via ANT+ with Edge only.  And other test: try to pair it via BT to the Edge only as speed/cad sensor, not via ANT+ and not to the phone neither and trying this way also.

I tried one more time today to remove all sensors from the edge and pair them again. Went out for a ride after and it has worked seamlessly this time. Could be just a coincidence, ill keep an eye during next rides. 

I had a sigma Rox 11.1 Evo before the Garmin edge and never had an issue with the speed or any data, perhaps the Garmin is more sensible or picky with the data than the sigma...

meneillos1980 yes, i noticed you have 4-5 sensors ("stumpi", "levo", "levo s/c" , a bluetooth one, etc) paired. i hope it will be good after this!