Sea Otter 2026: EMTB Specific Highlights

[slickrock]

Here is my followup review on the Rivian/ALSO TM-B test ride. A remarkably capable EMTB ride for a micro-mobility platform. Dario at PB seems to think so as well.

 

[TheKaiser]

Here is my followup review on the Rivian/ALSO TM-B test ride. A remarkably capable EMTB ride for a micro-mobility platform. Dario at PB seems to think so as well.

Yeah, that thing seems like it has some real juice. The thing that gave me pause about it is, if I'm not mistaken, the pedals don't directly drive the drivetrain, right? Instead the pedals are essentially a generator to help supply electricity and then the motor drives the drivetrain, correct? That seemed like it would subject one's pedal output to a lot of additional losses that aren't present on a regular ebike. But, on the other hand, if the battery is sufficiently big, and the pedal power sensing algo's are well tuned, I guess it may not really matter for most general purpose riding...as long as you don't deplete the battery.

 

[slickrock]

Yeah, that thing seems like it has some real juice. The thing that gave me pause about it is, if I'm not mistaken, the pedals don't directly drive the drivetrain, right? Instead the pedals are essentially a generator to help supply electricity and then the motor drives the drivetrain, correct? That seemed like it would subject one's pedal output to a lot of additional losses that aren't present on a regular ebike. But, on the other hand, if the battery is sufficiently big, and the pedal power sensing algo's are well tuned, I guess it may not really matter for most general purpose riding...as long as you don't deplete the battery.

Yes, the bike has an internalized pedal-by-wire design. And now there's another motor company using this approach. The approach obviates a mechanical dynamic transmission (no changing gears), just like a Tesla, and fully separates pedalling dynamics from power output dynamics, allowing: CVT, manual shifting, regen braking, kickback elimination.

True, there is a definite loss converting pedal generator current to motor power current, but there compensating factors:

1. Regenerative braking power recapture
2. Eliminates losses coming from mechanical gear shifting
3. Continuously variable transmission eliminates being in a wrong gear that reduces motor power delivery and efficiency of both the motor and rider.

The TM-B has a degrade mode if you deplete the battery, all your pedal input work converts to propulsion and powering the internal control system, which would definitely be a slog but at least you don't have to walk it home. And all the better if you are pointing downhill, you can recharge the battery on the return trip.