Bosch active line plus drag
- Thread starter IanV
- Start date
Stefan Mikes
Gravel e-biker
- Region
- Europe
- City
- Mazovia, PL
It could be an illusion. In high assistance modes, the motor contributes at the level of a professional competing cyclist. Many of us have the impression the motor's dragging when the assistance ceases to exist. I get such impression for the lightweight Specialized Vado SL in Turbo mode; "no motor drag" is guaranteed for that motor.
Do an experiment: Achieve your cruising speed of, say, 28 km/h in Turbo mode, and start your stopwatch when you have started coasting. Measure the time to the bike stop (no braking). Repeat for the Eco mode. Most probably decelerating from 28 km/h to 0 would take the same time.
William - Bosch Team
Well-Known Member
Hello IanV!
As Stefan Mikes said, this is likely an illusion. Due to the nature of the drive unit's integration into the bicycle, it is impossible for it to cause drag while coasting. A DU can definitely create some pedaling drag, as with the Bosch Gen2, but the DU has no way to apply any sort of unwanted braking force to the rear wheel. This should hold true for just about any mid-drive system... no way to cause drag while coasting. The only connection between the rear wheel and the DU is the chain or belt. Since the rear hub has a ratcheting mechanism, there is no way to apply braking force- only forward motion.
It may be a good idea to have your shop check your brake pads for rubbing, or your wheel bearings for smoothness. Both are age-old culprits of excessive drag while coasting, eBike or otherwise.
Side note: There are a few OEMs that use the Bosch Gen3 DU (Active Line or Active Line Plus) in conjunction with a coaster brake hub, but even so it would require deliberate back-pedal braking, and any unwanted drag would be due to a coaster brake hub issue.
I hope this helps!
As Stefan Mikes said, this is likely an illusion. Due to the nature of the drive unit's integration into the bicycle, it is impossible for it to cause drag while coasting. A DU can definitely create some pedaling drag, as with the Bosch Gen2, but the DU has no way to apply any sort of unwanted braking force to the rear wheel. This should hold true for just about any mid-drive system... no way to cause drag while coasting. The only connection between the rear wheel and the DU is the chain or belt. Since the rear hub has a ratcheting mechanism, there is no way to apply braking force- only forward motion.
It may be a good idea to have your shop check your brake pads for rubbing, or your wheel bearings for smoothness. Both are age-old culprits of excessive drag while coasting, eBike or otherwise.
Side note: There are a few OEMs that use the Bosch Gen3 DU (Active Line or Active Line Plus) in conjunction with a coaster brake hub, but even so it would require deliberate back-pedal braking, and any unwanted drag would be due to a coaster brake hub issue.
I hope this helps!
Similar threads
