Rivian's Tm-B Electric Bike
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Rivian unveils its TM-B electric bike with advanced features, sparking debate among HN users about its design, price, and functionality.
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NFS lock and unlock. GPS locator. Capacitance touchscreen controls. Hydraulic disc brakes.
Companion helmet with wirelessly connected brake lights, and noise cancelling(?!) speakers.
Why do we need to learn the same lessons over and over again?
I wish I had the automatic shifting module for SF's hills, but it's a nice to have that probably isn't as useful elsewhere
(Kind of amazed that wireless derailleurs became a thing. Replacing a simple mechanical device with complex tech requiring two batteries)
[0] (overall specs indicate a lot of weight, Rivian are not proud enough of any lightweighting to even print the weight, and their autos are also very heavy, indicating a lack of lightweight engineering discipline in that shop which may carry over to their other mobility solutions)
Not for an e-bike it isn't. In fact, I'd say if you're not rocking hydraulic brakes on an e-bike, you're asking for a bad time. I know that most lower end e-bikes don't come with them standard, but to me, it's a necessary and immediate upgrade for safety.
The only kind of weird thing I see here is the idea the pedals aren't actually directly connected to the drive train, they just turn a generator.
gears with a chain is more energy efficient.
But yes, other stuff seems to be features for the sake of features.
Edit: also, don't capacitive screens kinda suck if they get a little wet? like what, you just can't use the screen controls while it's raining without risking unlocking your seat 40,000 times in a half second due to a stray raindrop sitting on the screen? Feels like resistive would explicitly be superior here. You probably don't need huge accuracy for what should ideally be a spacious display anyways.
https://acronyms.thefreedictionary.com/NFS
NFC, Near Field Communication.
That said a GPS locator is great on an e-bike. They're high value theft targets, anything that makes them harder to steal, easier to track, or otherwise reduces the appeal of stealing one is a good thing.
Hydraulic disc brakes are a great thing even on non-electronic bikes. I won't buy another bike without them. My hardtail mountain bike, gravel bike, and e-cruiser are all hydraulic discs.
"activates and deactivates when the rider is nearby"
sounds iffy like that. I was riding a Forest bike yesterday where the user app and bike both have to connect to Forest's servers and it's kind of a pain.
The bike cost nowhere near $4500 and certainly doesn't have any "smart" integration other than a holder for my phone, which I added myself for $13.
The issue with juicero is that their hardware design was needlessly and insanely over complicated, like magnitudes past anything I’m seeing here - and they DRMd something that didn’t need to be DRMd (juice)
For this bike, those are features people regularly want in e-bikes and cost very little to add - the bike already needs a capable cpu for battery management and acceleration curve controlling.
These are features that people differentiate these pseudo motorcycles on. “We” have learned the lesson.
The helmet is very juicero tho
The pedals are not connected to the chain or wheels, it's surely a legal dodge to pretend it's a pedelec not a motorbike.
like technically, sure, it's obviously true. but for performance it only really matters when you would get air time with higher mass, and the lower mass stays in contact more. commuter e-biking generally doesn't get anywhere near those speeds or bump-sizes. (trail biking: sure! I 100% believe it's a sizable consideration there)
Also to note, they are very much marketing it as a trail bike in addition to a commuter so it's not surprising they would spend a bit to optimize for ride quality and traction.
E-bikes can have the motors on the wheel (hub-drive) or on the pedal (mid-drive). This choice is largely related to how much you want your e-bike to really be a scooter or really be providing pedal assist. As a consequence hub-drive e-bikes typically have a throttle while mid-drive do not.
A good mid-drive e-bike really makes it feel like you are a super human cyclist rather than riding a scooter. It leads to a much smoother riding experience if your aim is to still be essentially bicycling but you'd like to get moving faster and not break a sweet even on the most extreme hills.
Of course. But the pedals on this thing aren't even connected to the drivetrain. So what is the benefit in this specific case?
Unfortunately it seems to be difficult to engineer and build these wheel motors for reliability and longevity. They significanly increase the unsprung mass of the wheel which leads to increased wear on the hub components.
It's an e-bike. The competition is stiff, better looking, and better priced.
If they're lucky, this will appeal to university professors and over achieving parents of unsuspecting kids who want a cool bike but got an expensive dorky one instead.
edit: ask yourself why the median new car in the US sells for over $50k when you can easily find cars for less than half that price.
There's also a maximum power rating of 750 watts for all of these. I'm not sure where the "pedal by wire" feature is from a regulatory perspective, but to me this fits into either class 2 or 3 depending on what option you get.
> It also features a throttle good for 20mph where regulations allow.
That must mean they have a class 2 option.
Class 3 allows pedal assist up to 28 and throttle to 20
https://thecyclistchoice.com/resources/electric-bike-classes...
It would be nice to have the GPS automatically set the pedal assist max speed when riding on shared paths with pedestrians and people.
I have also seen road bikers on those same shared paths pedal faster than 20mph.
See how it just becomes a bicycle when it's discharged or broken? This is much, much closer to what we expected from the Segway.
If it is broken the pedals will just spin because there is no mechanical link between the pedals and the parts that make the vehicle move.
That's not even true for normal bicycles. Serious cyclists can spend massive amounts of cash on their rides.
Aside from that, if you're using this as a vehicle you want more than just the cheapest thing out there. Reliability and serviceability are important when not having the bike means you can't get to work or your kid's school.
True, but this bike is completely non-standard so sort of blows that. There isn't even a direct connection between the pedals and the wheels. If the electrical bits stop responding you don't even have a bike, you have a really awkward velocipede. Every other e-bike that I have ridden or seen is still a bike when there is no power.
Most serious bicyclists I know, some with wonderful bikes, still spent less on their bikes than the typical American spends getting the air conditioned seats option in their F-150.
Usb-c chargeable at 240W is divinely sweet. Maybe maybe some day dual USB would be nice (for the ER especially) but this is quite respectable. And by not trying to super fast charge the battery will live longer anyhow.
Being removable is another nice win, if not uncommon. I don't know which other batteries provide USB power even without the bike, which again is such a great nice to have: take the bike to a park then bring with an charge some phones or what-not.
In the future I really hope we see some battery alliances, making some form factors, and centralizing on usb-c. As would be good common sense. The overlap between a bike battery and standalone Delta or Ecoflow battery power station is huge, and Rivian here seems a little further along than most at hybridizing & generalizing a battery system: obvious win to anyone paying attention!
The modularity could be a major win too. I'd love to see a an e-bike maker go down the Ford Bronco path & add a bunch of attachments points and replaceable/modular pieces to the design, and release all the specs for free use! Even if it only is Rivian and some partners doing this here, this is the way, it feels like:
> The top frame of the TM-B is modular by design, so the bike can be transformed without tools into a cargo hauler, kid carrier, or cruiser with a bench seat.
Cargo haulers easily climb to the 6000$ ranges. And the massive 180NM motor here will not bat an eye!
One thing I'd love to see: a stationary bike mode. Bring it inside for the winter & do spin class, charging up the battery. The full series hybrid, no mechanical linkage, doesnt deel super super practical to be honest but it's interesting!
A lot of nice basic things that make sense. Like no longer needing special cherging equipment for reasonably good capacity chwrging (albeit most usb-c chargers will only be doing 100w for a while now, but that seems fine).
This bike seems to have only a single major modular system, but it comprises such a massive part of the bike: there's a big stem-post that attaches to the drive unit. Being able to swap that stem-post out for other things allows for really big changes, imo. You could build some really cool really neat different top-sides atop this bike, with really weird cargo or kid shapes.
I would love to see smaller level modularity too. I'm really impressed by the Bronco, and how they've clearly worked very hard to make it a "car as a platform", opening up as much space as they can for aftermarket parts & 3d printing people to build everything from cup-holders/interior fixing to body-panels (dunno the best link for this, but for ex: https://thebronconation.com/more-bronco-modularity-fender-fl...). I see Rivian / Also tapping that energy here in a way that moves far beyond what bikes today offer.
There's usually some kind of screw mounts somewhere, different bikes with different geometries need lateral positioning & control & it feels like >50% of the time what comes with the rack doesn't quite work.
It looks like most of these bike seats assume the bike already has some kind of rack installed. If there's already two horizontal bars ready to go then yeah it should be pretty simple to install: the hard parts done.
I feel like this debate over bikes are modular / no they are not is kind of silly. There is some part swapping, and some affixment points, but these come with great inconsistency across bikes and parts. But much more so than that, it feels like there's such a limited of reconfigurability for most bikes. There's the same bike underneath whatever you do, and the number of serious affixment points strongly limits how you can build up.
OTOH, with a battery this big, a generator powered by the pedals, and regen braking this thing has to be heavy. I'd expect it to weigh at least 80 lbs. More likely 100. The fact that their "specs" say nothing about weight suggests they're embarrassed about the weight.
It seems obviously true to typical racing or distance scenarios. And i notice the wind even at lower speeds on e-bikes in SF.
But between their quad scenario and what I imagine as the urban car replacement scenario it doesn't seem as obvious.
100kg rider at 15 kph = .24W-h kinetic energy. At this speed there is probably roughly 11N of air and rolling resistance, so the steady state power is about 3W-h per km. If you go 1km between stops, or more, the amount you can expect to gain by regeneration is extremely small. It could perhaps extend your range by 5%, generously.
If I'm understanding the math, maybe that scales the regenerative range extension % by your tolerance for pedaling?
If it's w.r.t. effect of low max power on low cumulative generation, I agree it does seem like a little silly to arbitrage your power generation this way. But maybe the tradeoff is worth it in some circumstances in their view?
Or maybe it's just a low cost addition as other commenters say.
I'm not sure which pressure sensor you mean, like in the brake lever? E-bikes with hydraulic brakes already have sensors for power cutoff (and in this case for brake lights).
Why existing bikes don't use it? Because you need software or a more complicated controller, and the amount of regenerated energy is indeed not that large.
Regen on the front wheel would be most effective - but then you've got two motors or a less-than-ideal front motor that adds unsprung weight and has similar traction issues during acceleration as the front unloads.
It's a shame - I think a lot of people want ebikes to work, but they're not as convenient as a pedal bike (especially not in small apartments) and usually they're too heavy to really use in blended pedaling/e-assist mode.
I don't see how this would be any different. Or, it's certainly not "moronic"
That combines with the heavy weight of an ebike, another 50lb+ of cargo in the saddlebags, plus my exceptionally fat ass means I burn through a pair of front brake pads about once a month if I'm running errands most days.
So the steepest roads in the world have small sections where the grade exceeds 30%; none maintain it or "average" 30%.
https://www.strava.com/segments/1504789
When I'm in my car the dash reads on the hills here between 12° all the way up to 16° on the switchback into the valley. The new market is up a 14° hill.
So closer to ~24% grade average maybe? It's damn steep is the point regardless.
Here in Seattle with all the hills it might
100 lbs would be unmanageable.
The point I really fell like I left out is that with that size and weight of the bike plus being able to haul 300lbs, the motor and battery combo is rated for 45 miles. Not once have I felt like I needed longer range. It's not that kind of bike. I use it for tooling around while shopping or leisure rides topping out at 35 miles. Even at 35 mile rides, by battery still has plenty remaining as I still heavily rely on my meat motor.
I suspect pedal-by-wire will only be slightly heavier since it doesn't need gears, but the range will probably be even worse.
800 watt hours for $4,500 is absurd too.
Absolutely not. Unless you have baby in a saddle and going 10mph
In an ideal world these would be great features to have, but in the real world, where so many places have a near complete absence of safe cycling infrastructure and bicycles are casually mixed in with giant trucks it's a bit of a scary notion to reduce your situational awareness with a great sound system and the distraction of doing your morning zoom standup while cycling to work (I've done this before lol, tho most of my commute is in separated bike lanes...).
This points to the headwinds to adoption and success of the Also, which is that so many cities are ambivalent and uninterested if not outright ideologically opposed to building safe all ages and abilities bike lanes. That sort of safe infrastructure is critical to the success of a product like this. It's really unfortunate.
It's worth noting that Hyundai had a similar issue when it entered the US market. It was an uphill battle to market itself to convince people to spend thousands of dollars of money on a no-name car brand.
There are hills near my house that my bike can not make it up without significant pedal assist.
If the motor and power electronics on this e-bike can only handle 750W peak, 500W sustained, as is common and I think is possibly even legislated in parts of the U.S., this bike will not be able to make it up serious hills.
With a normal e-bike, your pedaling is additive to the motor. That is not the case with this design.
I have a bike with an automatic transmission and it handles steep hills just fine.
But generally speaking, I would expect the bike at this price point to have an automatic transmission.
Critical features: 1. moderate weather protection 2. vastly improved crash protection 3. top speed above 50mph 4. luggage capacity of a small flatbed trailer
I acknowledge the utility of e-bikes for many; for me, I prefer my non-e bike when I want to ride my bike, but would love an e-motorycle as an alternative to 80% of my car trips.
https://www.theautopian.com/bmws-first-scooter-had-a-ridicul...
https://www.bmwmotorcycles.com/en/experience/stories/urban-m...
Great to see more manufacturers getting in on micromobility options.
Materials must be real strong to withstand all the torque forces without a rear triangle, right? Any other e-bikes like this?
Also, the "TM-B Reservation Token" smacks of egregious marketeering.
Still, this looks like a solid ebike.
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