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Rivian's E-Bike Spin-off Is a Pedal‑by‑Wire System That Works Like a Tesla
(www.gadgetreview.com)
It makes everyone think you're a Nazi supporter?
this post was submitted on 06 Apr 2026
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micromobility - Bikes, scooters, boards: Whatever floats your goat, this is micromobility
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Yet another one of these systems, they pop up every year or so. They're always less effecient than a chain, and rather pointless as pedaling normally on an ebike works better anyways.
This reminds me of another e-bike made by a car company, the Ford Bronco (youtube link). But that one is an entirely different idea - it's an expensive and not very practical mountain bike.
This Rivian one makes me wonder where muscle power from pedaling goes? Is it wasted? Is it all captured as regen? To me biking is a lot about efficient travel, and electric range is important. On a typical e-bike muscle power translates into forward thrust with efficiency somewhere over 95% (based on my vague understanding of bike efficiency). Using pedaling to generate electricity to run a motor will drop that efficiency to something like 30%, I think? That's a number I heard somewhere for regen brake efficiency on cars. And even on a motorized bike muscle power is significant. My 500 W bike advertises motor output "up to four times the power of a human cyclist". That implies that muscle input is over 20% of the total power most of the time, even on a high motor setting.
I guess I'm not the target for this bike. It's probably aimed at people who want to go very fast with no effort. Maybe I should look at it as more of a foot-operated throttle than pedals.
"Pedal by wire" is so dumb, for so many reasons.
It crashes and catches fire?
That doesn’t seem like a good selling point.
Don't forget trapping you inside, though I'm not sure how a bike would manage that.
What if you're cold?
$4500 for an commuter eBike.
I spent a third of that on a Lectric and it's been AMAZING.
To call this an "article" would be charity gone too far. It's basically a list of talking points, direct from the manufacturer.
But examining the merits for what it is, the first thing I noticed is that this supposedly has regenerative brakes on both wheels. That's... a bit odd, seeing as there's only one visible mid-drive motor. I can plausibly believe that the rear wheel is regenerative, since if their goal is fewer drivetrain parts, then eschewing the ratcheting freehub makes sense. But for the front, there's nothing which appears to sink energy, apart from what appears to be a conventional disc brake. Is there a motor hidden in the front fork? Or an induction pickup in the brake caliper?
But more pressing than that, a fully "pedal by wire" ebike may run afoul of the definition of ebikes currently adopted in several states. In California, CVC 231 and 312.5 define a bicycle and electric bicycle, respectively. The latter mandates that an ebike must meet all the requirements of a bicycle, but is allowed to have a 750 W motor, and must have working pedals. The problem here is that "working pedals" in CVC 312.5 and "propelled ... through a belt, chain, or gears" in CVC 231 can only reasonably be reconciled if the pedals are mechanically attached or linked to the belt, chain, or gears. Which has been the case for all legal ebikes... until this one.
As written, California law would put this two-wheeler into legal limbo. A District Attorney could certainly make a good legal argument that the Also TM-B is not an ebike, making it an unregistered motorcycle. If there is any functional, steady-state mode where the pedals can turn forward but not move the bike, AND the bike can run the motor without the pedals moving, I believe that would not meet the text of the law. The Legislature would have to change the definition to allow this.
As it happens, other reporting suggests that this has a 28 MPH (45 kph) max speed and also a throttle. That combination is not legal in California or anywhere else, as a Class 3 ebike.
28 MPH (45 kph) max speed and also a throttle. That combination is not legal in California or anywhere else, as a Class 3 ebike.
Actually class 3 ebike in lots of places permit 28MPH and throttle assist up to 20MPH.
I wouldn't be surprised if that's the case, but which places allow that?
Several states
Such as?
But for the front, there's nothing which appears to sink energy, apart from what appears to be a conventional disc brake.
Maybe it's like an electric car, which uses a combination of regen, and disc brakes. Depending on the car I think letting off the accelerator (in one-pedal mode) engages regen, while the brake pedal uses the disc brakes, and does not capture energy. Or in some cars the brake pedal uses regen braking for a portion of its travel, and disc braking if you press harder.
Maybe this bike uses regen when you stop pedaling, and has regular disc brake levers for faster stopping? Or maybe regen back-pedaling?
The phrasing from the "article" says this:
Regenerative braking recovers up to 25% of energy while integrated traction control prevents wheel slip. The TM-B monitors both wheels independently, adjusting power output in fractions of a second to maintain grip.
The only way I can parse this is if "power output" means the regen power. But even so, it explicitly says both wheels, and I can't figure out how it would do that. Or perhaps "power output" also includes the dissipated heat from friction braking. Truly a strange statement to try to pick apart
Lmao I've been throwing this pedal-by-wire concept as a joke for years for how stupid it is 🤣
Maybe instead of pedal by wire, they can use a gear, then link that gear to a smaller gear in the back with a belt or chain. Just spitballin'.
Welp that article guaranteed I’ll never trust that review site.
Looks shitty and dumb.