Rivian ALSO TM-B Urban / EMTB

[slickrock]

https://www.pinkbike.com/news/rivian-spinoff-introduces-transcendent-mobility-urban-emtb.html


This is an interesting development. Though a stretch to cast it as an EMTB, there is a lot going on tech-wise that could have and impact in our sport and force a rethink on how EMTBs can evolve. Just getting this post here started, and will loop back with my take.

Edit: Here's my take:

Yes, it’s very heavy. And way too urban-looking in a way that might get you beat up in certain rural locales in the US. It has small wheels. And lots of electronics waiting to malfunction. Probably lots of plastic as well. At first blush, it seems to have absolutely no business on MTB trails, let alone be cast as an EMTB at all in Pinkbike’s heading.

Yet…there are videos of riders this bike on technical trails (not just influencer stuff, but on the ALSO site itself). It is chock full of electro-mechanical technology and suspension design. It has:

1. A magnesium Hybrid / E-CVT Pedal-by-Wire MGU
2. An inverted suspension fork
3. High-Pivot Dual suspension with 120mm front and rear
4. It is belt-drive
5. Concentric rear suspension, so no belt tensioner required.
6. Regenerative braking
7. 180NM of Torque
8. Changeable Class 1, 2, and 3 modes
9. 800WH battery (more like 1100WH with regen recapture)

There’s more features, but I want to stick with these as they relate more to EMTB:

Hybrid / E-CVT / Pedal-by-Wire MGU​

This is by far the critical piece of the bike that unlocks everything else in its design:

MGU​

First it’s an mid-drive MGU, which which in of itself is something the EMTB community has been longing after, but currently the market has almost no options: you can pretty much have any MGU you want, so long as it’s Pinion. There are advantages with MGUs that are inherently quite appealing, but to me the most notable ones are dispensing with rear derailleurs and dinner-plate cassettes, unweighting the rear-end, and opening up belt-drive over chains.

High Pivot + Concentric Wheel Path Rear Suspension​

Second, it’s a high-pivot MGU. The pedal shaft and the drive shaft are separate, which allows the drive shaft to be placed in the exact position where an idler gear normally be for a high-pivot bike. The original Effigear gearbox, though a fully mechanical transmission, has a similar design.

What’s more is the suspension has a Concentric Wheel Path- No Chain Growth and no Spring-Tensioners. The drive shaft is in line with and fore the main high swing-arm, so the swing arm pretty much pivots about the drive shaft, so there is effectively no chain-growth over its travel. And so no spring tensioner is need to keep the belt taught over its travel. Add to that belt drive and you a get zero chain-slap dual suspension bike. Conceptually this very similar to the Cavalerie Anakin V2 - albeit a analog bike, it counts as having one of the most unencumbered rear suspension designs for a long travel MTB.

Hybrid / E-CVT / Pedal-by-Wire Transmission​

This aspect is huge in that it attacks a major challenge with current MGU designs, and I’ve elaborated on this topic extensively on this thread to the potential of Hybrid/E-CVT transmissions. This short of it is that current MGU’s basically slap a mid drive gearbox which house a complex, heavy cluster of spur gears onto an EMTB motor. Hybrid/E-CVT designs, however, use single planetary gear in concert with two motors to continually adjust gear ratios in a stemless fashion (think Toyota Hybrid Drive shrunk down EMTB motor size), but the rider is still mechanically connected to transmission through the pedal shaft through the planetary gear setup. [Edit: a hybrid/E-CVT transmission may not be used at all in the bike]

But here, the TM-B goes one step further and fully disconnects pedal shaft from the drive motor by only connecting to a generator: pedal forces charge the battery with the generator and the battery drives the motor; a design that can be called Pedal-by-Wire. Now the pedal-by-wire (PBW) concept has been floated for a few years now, but most of the concept bikes seen have the generator mid-drive and the motor on the rear hub, effectively creating a chain-less, non-mechanical interconnection between the cranks and the rear wheel. What’s interesting here is that TM-B keeps everything co-located at the mid-drive, which would be a huge benefit for EMTB, basically ridding the unsprung weight with a rear hub motor.

Pedal-by-Wire, however has two consequences, one of which is an entirely virtual pedaling experience and the other is the lack of a degraded failure mode (lose power to the motor or empty the battery, and the bike can’t be pedaled home)

Like with automobiles that have steer-by-wire, where the steering experience is fully simulated, PBW fully simulates the pedaling experience. Torque feel at the pedals, cadence vs speed and even gear shifting is fashioned in software modes that can be changed at will. Of course, work input is real as you transfer pedal power to the battery. But the “feel” at the pedals is hugely important and may feel foreign at first, like when I first test drove a Tesla in 2014, with regenerative braking when letting my foot off the pedals.

Speaking of which, this bike actually has regenerative braking. The Hybrid/E-CVT design allows the drive motor to instantly turn into a generator and recharge batteries. For this work the hub needs to be a “fixie” with no free-wheel, so the sprocket and belt are always in motion even while coasting. A clear advantage here is improved battery life, especially for EMTB use. Think of all that heat energy dissipated at the rotors and calipers that’s glazing your pads instead going to recharge the battery. The effect would be like adding some 30% to battery capacity. In this case the smaller 500WH battery may be all you need.

There’s a lot more to unpack here regarding the ride ability of the bike, like off-the-line performance with 180NM torque on tap, inverted fork, sprung weight, bb-height, etc. Who knows at this point the geometry and kinematics of this bike. Puppy's gonna need a bash guard for sure.

And I haven’t even gone into its retrofittable modular design approach that can take the bike from being a cargo bike down to a EMTB and back. Clearly there are design compromises here that would keep the TM-B from being a go-to EMTB. But I can imagine a future purpose-centric EMTB that could make use of this raft of technologies to drive the sport forward. I’m looking at you, DJI.

 

[f1xedgear]

RIP Amflow

 

[slickrock]

I found a promo video Interesting close ups of the MGU and suspension, but need to wade through a lot urban tech I could easily do without.

 

[TorAtle]

Great writeup, @slickrock. Looks very interesting at least as a commuter bike.

 

[Mcharza]

It's not a bike. It's e-moped or Class 3 ebike as they say in US.
But still very interesting as a commuter vehicle.

 

[Rando_12345]

Agree with most above, the tech is really cool, but it's more of a e-moped. Has anyone seen any weights discussed? Just to get an idea about whether the pedal by wire concept could apply to our emtbs in the future?

Would definitely replace my wife's commuter ebike with this, even though in Europe I guess we would only have pedal assist mode restricted to 25km/h which defeats a lot of the point of this bike.

 

[Ndanger]

The question becomes, is the the regeneration efficient enough to be practical .

 

[slickrock]

It's not a bike. It's e-moped or Class 3 ebike as they say in US.
But still very interesting as a commuter vehicle.

Agree with most above, the tech is really cool, but it's more of a e-moped. Has anyone seen any weights discussed? Just to get an idea about whether the pedal by wire concept could apply to our emtbs in the future?
...

It's ironic that when you go to any MTB forum, you get lots of people calling and endlessly trolling that all e-bikes - even all Class 1 EMTB brethren will no throttles and 250W motors (i.e. the EMTBs we ride) - are mopeds. It also doesn't help that DJI/Avinox and now Gen 4 Levos have broken the Class 1 limits which opens this line of attack even more. Taking Pinkbike parlance in regards to this bike: let's just say it's not an EMTB, but it's also not not an EMTB.

Where this bike could be best placed are with those cheap Chinese heavy fat tire, mondo battery, 1000W motor electric mini bikes, that cost a couple of K with banana seats for saddles, where the firmware can be overridden so the bikes can go like 50MPH. The TM-B is certainly power enough, and heavy enough, and unfortunately, yes it does have a throttle (the single control that makes any ebike more like a moped) and looks to be the Apple version of this bike. But this is not why I wrote the OP on this forum, as this would be disqualifying out of the gate here.

My main point is to ponder all this high-tech propulsion and suspension design all being put into a single bike design that has enough financial backing to be viable in its own right. And if it can be done with this multi-purpose ebike and done well, than it can also be done with a true EMTB design, with geometry, travel, durability, and light-weight agility needed for our sport. It seems more than feasible to pare down a hybrid MGU into a small mid-drive unit that can directly power a high-pivot drive shaft and have a swingarm pivot around it. Basically an Anakin V2 with a hybrid MGU - definitely would be my dream bike. It just gonna take a bold, deep-pocket bike industry player to make the move to abandon derailleurs, chains, cassettles, tensioners, free-wheels, spur gearboxes, and ebike motors without built-in transmissions. And It looks like Rivian just took the first step.

 

[ValActionT 750]

There are multiple articles along with Also’s web page. That would answer most of people’s question.. Weight is what one would expect low 80s. Regen can be in theory is about 25%. The biggest thing I like is someone finally doing something entirely technologically different. Pedal by wire wow. Not to mention the power output. Basically everything is electronic. It even locks the rear wheel. I personally am intrigued.

 

[Doomanic]

It's not a bike.

It's an abomination...

I've heard a rumour that Haibike are looking to hire the design team...

 

[RustyMTB]

Homer you say? Rivian ebike you say?

 

[ValActionT 750]

Sill people, not a bike is exactly what many have been saying about e-bikes. Prejudice is apparently ingrained no matter what. Reminds me of the time a motor was 1st fitted to a carriage.

 

[slickrock]

A few of more design features I feel that are worth mentioning:

One, is a form of ABS, as this seems to be a pass-along feature because the bike is already providing coordinated regenerative braking with disk braking, depending on how strong you grab the brakes. From picture of the front wheel, the disk has timing notch ring similar to what you see with the Bosch ABS system.

Second, the square magnesium casing not only houses the motor, drivetrain and transmission, but also the core support structure of the entire bike, including the swingarm, seatpost, downtube and battery compartment. It's a novel design for sure, but flies in the face of the front-triangle bike framing that nearly all EMTBS rely on. But there may be another reason why this large casing exists on this bike.

After examining the open box chassis with all the gearing and motors somewhat visible, I'm starting to think this Drive-by-Wire system may likely not have a hybrid-based CVT inside. Instead, it may use a single-speed transmission with a super high-RPM motor, like exists on current Teslas/Rivians: the motor basically hammer-torques off the line and the thing revs and spins out torque at top speed. This would highly simplify and lighten future EMTB MGU designs if a like in-kind approach were taken with an MGU motor design. Some city bikes have taken this approach (basically slapping an ebike motor onto a bike without a derailleur) but these are are not taken seriously because they are hampered torque-wise because the torque of typical ebike motors is quite limited (i.e. they are either slow off the line with terrible hill climbing ability or wind out to quickly to get any decent speed). A Rivian-based high-RPM motor would solve the the entire variable geared-transmission system of a e-bike in one fell swoop by effectively obviating it. Some supporting observations that point to a single-speed transmission:

1. That huge 62 tooth rear sprocket compared to small drive sprocket. This already provides a serious step down gearing that takes the load of the internal planetary gear system, opening up off the line torque. This step down would not be necessary for hybrid transmission as it could easily support wide continuous gear range on its own.
2. I'm not seeing secondary motor/generator connected to the planetary gear and it doesn't look like the ring gear rotates at all, both the absence of which are essential to a hybrid/E-CVT design. And if the primary generator motor were to participate in a hybrid drive transmission, then it would be mechanically connected and cease to be pedal-by-wire.
3. Maybe the mondo chassis is also there to keep the motor operating stably at high RPMs and to provide significant heat synching when hyper-driving the motor.

Admittedly, this is all conjecture until ALSO/Rivian spills the beans on the internal details of their MGU.

 

[RustyMTB]

Reminds me of the time a motor was 1st fitted to a carriage.

Yeah? How old are you exactly?

 

[Fangs2k]

may use a single-speed transmission with a super high-RPM motor, like exists on current Teslas/Rivians

It’s not just Rivians and Teslas, every EV uses that approach.

Interestingly, one of the best EV motors out there at the moment is the Volkswagen APP550, Munro did a tear down to demonstrate its engineering/build.

VW are a major shareholder in Rivian, although not sure how much cross over there is between EV passenger cars and e-bikes, other than they use motors.

 

[slickrock]

It’s not just Rivians and Teslas, every EV uses that approach.

Interestingly, one of the best EV motors out there at the moment is the Volkswagen APP550, Munro did a tear down to demonstrate its engineering/build.
...

Agreed. And EVs have always had the advantage at sprints , not just off the line, but along the whole course without having to pause to change gears, either mechanically or automatically. But this, up till now, did not at all seem applicable with how we think about power and transmission delivery with emtbs. Now, Pedal-by-Wire totally unlocks this approach, making it available to emtbs in the same way Tesla's in circa 2014 unlocked 0-60 and Nurburgring performance compared to ICE cars. To most of us (me not included), unfortunately, this would seem like sacrilege to the very mechanical roots of EMTBs (i.e. descendants from MTBs). Just like Ferrari swearing that they would never, ever, ever make a pure EV. Ahem.

 

[Ndanger]

Pedal-by-Wire totally unlocks this approach

In a sport where efficiency is a primary concern down to fractions of a gram using a generator for propulsion seems counterintuitive.

You will probably lose 30 to 40% of pedal power when you convert to electricity and run an electric motor. With ordinary components expect 60 to 70% of the pedal watts to reach the wheel. So if you expend 100 watts of pedal power to the bike will only result in approx 60 watts of power.

Direct mechanical chain drive (no conversion) is usually ~95% efficient, so converting to electrical is A/ unnecessary with the ability to directly pedal the bike. and B/ levels of efficiency losses that would not be acceptable for our sport.

What it does accomplish is something I have been surprised has not been done before ABS braking. Convert braking energy into electricity. My XT brakes wear out my hands on long descents, I fantasize on long braking stretches that the battery would be charging and my hands relaxing the way down the hill.

 

[ValActionT 750]

One needs to remember the pedaled generation is to supplement (increase) battery capacity. Hence the up to 100miles with the bigger battery. Sweet for those who how have distance anxiety. You don’t have to pedal at all, the way I’ve read it.
Also it’s not being marketed as a mtb. The knobbie tires and 120mm fork is forest road fun. Nothing more. It’s, to me, another option for level 2 two wheel transportation. I could be totally off base. Not sure if i want let alone need one. My buddy has a Rivian, the technology is pretty cool. I am intrigued by this bike/scooter/abomination whatever you want to call it. I mean it even greats you by name. Expolosion!

 

[slickrock]

In a sport where efficiency is a primary concern down to fractions of a gram using a generator for propulsion seems counterintuitive.

You will probably lose 30 to 40% of pedal power when you convert to electricity and run an electric motor. With ordinary components expect 60 to 70% of the pedal watts to reach the wheel. So if you expend 100 watts of pedal power to the bike will only result in approx 60 watts of power.

Direct mechanical chain drive (no conversion) is usually ~95% efficient, so converting to electrical is A/ unnecessary with the ability to directly pedal the bike. and B/ levels of efficiency losses that would not be acceptable for our sport.
...

I should have been more clear that benefit I was calling out was not specifically pedal-by-wire per say, but more the continuously variable / transmissionless aspect of the this ebike. E-CVT / Hybrid drive MGUs like Revonte (now defunct), Villiger Dynamic, and the next-gen Owuru/E2 stepless transmission MGU all have similar benefits in that power delivery is utterly maximized and optimal to keep the motor in its sweet spot power/efficiency curve and absent the latency (clear power pauses) with manual shifting engagements (Here is example of Revonte from years ago, where acceleration is fast and continuous from its continuous hybrid transmission).

Regarding energy loss from pedal-by-wire, we'll see just how much is lost in the tradeoff when adding regen braking, stepless transmission, belt-drive (at speed where it's more efficient than chains), and clutchless high power/efficiency motor is added to the mix. And when high energy-to-weight density solid state batteries come around...

 

[TorAtle]

The design is interesting, but my gut feeling is that a 2 motor e-CVT would be better in many ways like torque management and efficiency (at least in a hilly terrain). This "Also TM-B" bike also have 2 motors, just that one of them is a generator.

 

[slickrock]

The design is interesting, but my gut feeling is that a 2 motor e-CVT would be better in many ways like torque management and efficiency (at least in a hilly terrain). This "Also TM-B" bike also have 2 motors, just that one of them is a generator.

Agreed. What's clear is that a hybrid/E-CVT would at least be more efficient than pedal-by-wire, as the crank provides mechanical connection to the transmission. Yet... another tech feature that’s lurking in this pedal-by-wire e-bike is Traction Control, and I should have saw this coming, given the regen/ABS and pedal-by-wire aspect of the bike, where the bike can sense front wheel speed and compare it to rear wheel speed and instantaneously control motor output, as elaborated in this video. And is possible that this can only be made effective with a PBW system, because the motor is fully disconnected from the crank.

What makes off-the line speed of the Tesla Insane / Ludicrous mode possible, is not just stepless transmission of EVs, but also the digital traction control that instantly de-powers the motor when the tires start to slip, basically keep static friction maintained to maximize traction under heavy acceleration. The analog of this for EMTBs is that could you could be in race mode on a loose-gravel trail, and still get full power to your bike immediately but without spinning out the rear wheel or in the case of a firm grippy loam trail, not wheelie out the front end. I’ve seen demo’s of DJI motor ebikes at max power causing wheelies off the line, so tech like this would be welcome in future EMTB designs.

And to be clear, while off the line performance would be cool, it’s not particularly important to EMTBs.. But what is important is to have this capability on loose technical steep uphills where you don’t have the needed momentum, like where on my old LEVO under max power I had troubles- I would either spin out on roots or lose steering when my front wheel lifted from excess torque. Bosch Gen 3 had better manners in this regard, but I imagine traction control would be markedly better.

 

[TorAtle]

Another quirky aspect is that the bike won't go faster than the motor assist cutoff limit, 25 km/h in europe, even if you pedal hard at that speed (assuming no hand throttle to make it legal here). I've mentioned before that there will probably be some rubber-band effect with an e-CVT, but the rider input disconnect will be much worse when you're basically just pedaling to charge the battery. For "sporty" riding, mechanical gears are superior IMHO.

 

[slickrock]

Another quirky aspect is that the bike won't go faster than the motor assist cutoff limit, 25 km/h in europe, even if you pedal hard at that speed (assuming no hand throttle to make it legal here). I've mentioned before that there will probably be some rubber-band effect with an e-CVT, but the rider input disconnect will be much worse when you're basically just pedaling to charge the battery. For "sporty" riding, mechanical gears are superior IMHO.

Wow, this is a interesting dilemma. Normally, a motor speed limit cutoff just means human power is responsible to get the bike to go any faster after that limit. If you got the strength or pointing downhill and have taller gearing, you can go faster without breaking any EMTB laws. Motor cutoff on Pedal-by-Wire would be disastrous if not totally unsafe. I see two possibilities to deal with this:

1. A hard speed limit for the ebike. Attempt to pedal past this limit would be met with either a no-torque pedal spinout, like you quickly ran out of tall gears; or step up generator torque to just charge the battery faster, to signal to rider that speed limit has been hit.
2. Reduce the motor assist to simulate the dead battery mode of the ebike, where only pedaling energy only goes to the motor to propel the bike with no extra assist from the motor from battery energy. Technically, this could allow the bike to go faster than speed limit, depending on rider strength, downward grade, and pedal torque to simulate taller gearing. This approach would be more appealing, IMO, as it would better simulate motor cutoff with standard emtb.

Clearly though, ALSO/RIVIAN, must have already dealt with this issue - it would be curious to see how they approach it. One, thing, though, when the ebike is in EMTB mode, it is transformed into a Class 1 steed - throttle is disabled, simulated gearing is changed, and speed is limited to 20MPH (of course rider experience at this point is TBD per above). That said, when in Class-2 mode with just throttle applied, the bike tops as 20MPH.

 

[slickrock]

Got confirmation from Rivian/Also that the Class 1, 2, 3 motor speed limits that the bike provides is similar to the dead battery mode described in the last post. The bike provides zero "net" assist at that point, so the rider can pedal past the speed cut off of the motor if needed. IOW, the virtual transmission persists after cutoff.

 

[Ndanger]

Got confirmation from Rivian/Also that the Class 1, 2, 3 motor speed limits that the bike provides is similar to the dead battery mode described in the last post. The bike provides zero "net" assist at that point, so the rider can pedal past the speed cut off of the motor if needed. IOW, the virtual transmission persists after cutoff.

Interesting… So, I assume that the phrase “the virtual transmission persists after cutoff” means that the bike’s electronic system that simulates different gearing or torque characteristics continues to function even though the motor is no longer adding power.
“Zero net assist” must mean that it equals no net power added or subtracted by the motor, allowing the rider to pedal beyond the legal speed limit. I assume that the bike still feels like it has gears or a transmission even after assist stops. My question is that the amount of force to ride the bike will be as follows:

In regards to pedaling against a chain drive train directly with ~95 % efficiency to the real wheel and what the rider would experience with the effort to mechanically drive the rear wheel. Instead it will be pedaling against a generator with ~60 % efficiency to electrically drive the motor to power the rear wheel.

Roughly speaking, 280 watts are required to maintain 10 km/h on a 10% hill with a typical chain drivetrain.

To maintain 10 km/h up a 10% grade with a 60% efficient drivetrain,
the rider must produce roughly 460 watts at the pedal.

A fit recreational rider can sustain 200–250 W for several minutes. A pro MTB racer can sustain 350–450 W for long climbs.
On steep technical trails, speeds are slower, so required power might be lower, but torque demands (force at pedals) would be higher.

 

[TorAtle]

Got confirmation from Rivian/Also that the Class 1, 2, 3 motor speed limits that the bike provides is similar to the dead battery mode described in the last post. The bike provides zero "net" assist at that point, so the rider can pedal past the speed cut off of the motor if needed. IOW, the virtual transmission persists after cutoff.

Is that legal?

 

[slickrock]

Interesting… So, I assume that the phrase “the virtual transmission persists after cutoff” means that the bike’s electronic system that simulates different gearing or torque characteristics continues to function even though the motor is no longer adding power.
“Zero net assist” must mean that it equals no net power added or subtracted by the motor, allowing the rider to pedal beyond the legal speed limit. I assume that the bike still feels like it has gears or a transmission even after assist stops. My question is that the amount of force to ride the bike will be as follows:

In regards to pedaling against a chain drive train directly with ~95 % efficiency to the real wheel and what the rider would experience with the effort to mechanically drive the rear wheel. Instead it will be pedaling against a generator with ~60 % efficiency to electrically drive the motor to power the rear wheel.

Roughly speaking, 280 watts are required to maintain 10 km/h on a 10% hill with a typical chain drivetrain.

To maintain 10 km/h up a 10% grade with a 60% efficient drivetrain,
the rider must produce roughly 460 watts at the pedal.

A fit recreational rider can sustain 200–250 W for several minutes. A pro MTB racer can sustain 350–450 W for long climbs.
On steep technical trails, speeds are slower, so required power might be lower, but torque demands (force at pedals) would be higher.

My guess is that it's similar to the dead battery mode (where you would have to put in more energy to get past the conversion efficiency), but not the same. If battery levels are there, I don't see why not to have power delivery compensate for the PBW efficiency loss so that pedal power in = rear wheel power out at the speed limiter point.

Is that legal?

I guess we will see, as it's probably a grey area. I haven't researched US (and more over California) laws, but Euro laws may be different as well. If Rivian can show that power in equals power out at the limit, it might be harder to challenge.

 

[slickrock]

OK, I finally go to test ride this high-tech beast. I had a missed opportunity to test this bike back in January but missed the invite. That would have been on a flat asphalt parking lot. But at Sea Otter, I uncorked it on the available MTB test trails and the results were surprising, as a bike this urban should not have any business on chunky MTB trails.

The reason for my OP was to introduce the kinds of technologies that could make their way into future EMTB designs, but I never gave it much serious thought that this bike could potentially be used as an EMTB right now. Yet, there are aspects of the bike that can lend itself to MTB usage:

1. That mini–Fox Podium inverted front fork
2. ABS braking with full battery regeneration
3. 180NM or usable torque with traction control
4. Concentric rear wheel path
5. Stepless Transmission (Pedal-by-Wire)
6. Manual shifting (virtual)

So, I decided to test it as an EMTB to see how these features could add to experience, as a future preview of what it would be like ride an EMTB with all this tech.

Bike setup and particulars:

1. The bike is a single size. I tested the version that had high riser bars, with MTB saddle attachment and no racks.
2. The bike can be ordered with knobby tires, but all the bikes for demo were on city slicks.
3. The throttle is push-button rather than twist throttle that you see on many Class 2 bikes and Surrons. This to me is a huge benefit because it biases you to pedal the bike and provides hand grip stability on choppy terrain.
4. There are Class 1, 2, and 3 modes. The Class 1 mode disables the throttle and limits speed to 20MPH. While on the trails, I was in this mode.
5. The bike is 70+ lbs but felt lighter than expected when I lifted it with a full size battery.
6. The bike is still pre-production as of this date, so refinements are still likely, mainly in ride control with software updates.

Ride Notes:

1. Automatic modes: there are 10 steps of assist you can select, and they felt like linear steps (from 1 to 10, from lowest assist to highest). My sense is that the assist input is driven primarily by pedal torque over cadence. In this way it was a bit like the Bafang motor in that when you give it more pedal force it amplifies it. As you pedal harder, the bike does go faster, but I was hoping for some more cadence bias here because there is balance between cadence and torque that dedicated EMTB motors give you (especially in comparison to the new Avinox M2S motor). This experience is slightly better in all-terrain mode, but I feel this is the main feature that needs improvement but is the easiest aspect to tune with a software update.
2. Manual Mode: There are 10 virtual gears (1 the lowest to 10 the highest) and you use a rocker controller on the right handlebar. This was an incredible experience and really made the bike shine for EMTB. Imagine the fasted, smoothest shifter in the world and multiply that by 5. It provided instantaneous distinct haptic feedback at the pedals like it was shifting something mechanical and instantly conveyed the proper sense of power delivery through pedal force and cadence. Under technical uphills this provided a natural and familiar form of assist you would come to expect from a standard EMTB.
3. Motor and Power Delivery: Power was prodigious and responsive, both dynamically and off the line. In class 2 mode, pushing the throttle button produced instantaneous power, but the traction control system keeps the bike planted at take-off. Since the transmission if fixed, it’s the wide power range of the custom Rivian motor that comes into play here. At the pedal, depending on the assist level and mode, power delivery could be fully manifest. That said, the motor feedback felt cruder and louder than what experienced with Gen 5 CX and M2/M2S motors. Something closer to the Gen3 CX, EPS8, and 1.1 Brose motors about 4 years ago.
4. Traction Control: The bike has a speed sensor at the front wheel, and since the motor directly powers a fixed wheel hub at a known sprocket size, this combination allows the bike to control traction which such a high torque output. This was very evident with power delivery control on pavement and flats, as mentioned above, but also in technical uphills. This allowed me to blast past even Avinox riders on the test trails. However, running slicks on gravelly uphills was causing slippage in the top level automatic assist mode - there was a point where I spun out under full power because of mode confusion I had between automatic and manual modes ( level 10 on manual is the least assist at low speed but level10 automatic is conversely the greatest assist at low speed). The ALSO folks said the experience would have been different with actual MTB tires (an order option), but I feel some additional refinement is in order for off-road use.
5. Regen and Braking: This was one of the hugest surprises. This is hands down the best braking performance I’ve had on a bike. A lot has been said that this bike support for regenerative braking, but the real delight here is the supporting ABS capability of the setup. If you grab the brakes, the tires don’t skid, it felt endo-proof, so there is max static braking force available at all times, which compensates the bikes heft and improves riding dynamics. Regarding regen, it was non-invasive to handle-squeeze feel and the transition from regen braking to actual caliper braking was subtle. I don’t need to stress how important braking feel is for MTB/EMTB riders, and had the brake felt was vague or foreign, that would have been a real problem.
6. Suspension: This was the other big surprise – the suspension and shock performance were way better than expected. The bike sports what looks like a mini–Fox Podium fork with Kashima-like coatings. With 4 inches of travel, it felt subtle and hade enough mid-stroke performance to use the full travel without hard bottom outs. The rear suspension is high-pivot and active which a concentric wheel path that kept the rear wheel planted during chunked downhills. It helps that the rear suspension was unencumbered due to the absence of a dinner plate cassette, derailleur, and a whipping chain, which is a benefit that all MGU EMTBs share. And to top it off there is no suspension kickback felt because there is no chain growth and besides, pedal-by-wire physically disconnects the rear transmission for the pedal.
7. Geometry and fit: As of yet, there are no published geometry numbers. The biggest problem here is that there is only one size. It helps that bike is step-through, especially for shorter riders. In this setup, and with my small stature, I pretty much had to slam the seat post all the way down to get a good riding position. Taller folks could conceivably put a wireless dropper on this thing, though I did not ask ALSO if that was possible. As such, I had to ride the bike like in the old days when droppers didn’t exist. Still, with the low COG of the bike (motor, transmission, and batter), combined with riser bars, and with great suspension and shock performance, I was able to extract good trail performance, which is way more than I ever would have expected from a micro-mobility ebike with a kickstand. YMMV for other riders of differing weight and stature.

Overall there was a level of consumer surplus I hadn’t expected for actual EMTB use. At $4500, it’s a veritable steal with all the technology that’s packed into this bike. It feels like a concept bike made real. It’s incredibly proprietary and hopefully the Rivian service network can be leveraged for support. Many of us have been patient, waiting for the next big leap in tech to advance the EMTB sport, but we keep waiting for MGU’s and stepless transmissions to take hold. If you are impatient and don't mind the bike not looking the part, you can basically get this now with this bike.

 

[TorAtle]

Great writeup! Sounds like a really cool urban bike with some real advancements. Wheel size is interesting (mtbs have moved from 26 to 27.5 to 29). I'd love to buy one, but I'm guessing we have to wait until 2027 in Europe. In the meantime I've ordered an Orbea Muga 10 which is a full suspension Bosch + automatic Enviolo setup just to get a feel for how that would work for commuting and leasure rides. So somewhat same riding experience as the Also, but with older less optimal tech.

Niche Mobility has a similar motor/gearbox as the Also (generator + traction motor): Home - Niche Mobility.

Mechanical gears (like Pinion MGU), generator + traction motor or e-CVT? I guess we'll have to wait to see how this plays out.

 

[slickrock]

Great writeup! Sounds like a really cool urban bike with some real advancements. Wheel size is interesting (mtbs have moved from 26 to 27.5 to 29). I'd love to buy one, but I'm guessing we have to wait until 2027 in Europe. In the meantime I've ordered an Orbea Muga 10 which is a full suspension Bosch + automatic Enviolo setup just to get a feel for how that would work for commuting and leasure rides. So somewhat same riding experience as the Also, but with older less optimal tech.

Niche Mobility has a similar motor/gearbox as the Also (generator + traction motor): Home - Niche Mobility.

Mechanical gears (like Pinion MGU), generator + traction motor or e-CVT? I guess we'll have to wait to see how this plays out.

Wow! I completely missed the existence of the Muga 10. I think we are seeing a new category emerge with these bikes: Mobility-EMTB. It's worth as separate discussion. Also, already posted here on Niche. Didn't realize that Enviolo added an electronic automatic transmission to their mechanical CVT hub, not unlike what Pinion did their gearbox - makes a lot of sense. These are all good signs pointing pointing in the right direction.

Forgot to mention thoughts on Rivian wheel sizing during thest. It's strange, but the thought of it never came up on the ride - perhaps the surprisal of the bike suspension, shifting, power delivery, traction, etc took over the experience. There was something about the whole bike design that made wheel size comparatively work well off-road.