New indoor bike, meet the TrueBike

Yesterday, the bike finally was ready for pickup. I was able to pick it up at the headquarters where the bike is developed and also put together, which is only 40km from my house. This bike is produced by a small startup company, only 100 or so have been sold in 2020 in the Netherlands and Belgium, which is also their max production capacity. But current plans are to expand production and also offer in the US. They are now producing version 2.0 after receiving feedback from the early adopters.

The unique claim is that this is the first robotized bike. The crank is connected to a motor by a chain and there is no flywheel. Every split second the software measures the forces applied on the pedals and uses AI to predict what you will do next, in order to offer the same ride feel as what you would experience outside.

What I am wondering is how this differs from the Neo Bike where the simulated flywheel also means that the resistance is being adjusted throughout the pedal stroke. I guess it is all about the algorithms used to control the resistance. What TrueKinetix has developed is a way to use robotics to simulate physical movement. It is applied first to a indoor bike, mostly because of commercial reasons, but the same algorithms are also applicable to simulate robotic weightlift machines for strength training without weights or indoor rowers.

Anyway, my experience so far is that I immediately ordered one back in December after having booked a demo at their headquarters. This bike is really about the ride feel and after reading their claims, I had to try it out and see what it was about. I was using a Kickr Core so that is what I have to compare, and the difference is noticeable. Maybe the best way to describe it is by what you sometimes hear in reviews of trainers, how it is so smooth. Of coarse all these trainers feel smooth as in that there are no abrupt pulls on the crank, but the smoothness of the Kickr feels like a more constant resistance with the pedals accelerating down fast, the moment that I apply power, while on the TrueBike it really feels like there is this gigantic stone wheel at the back that you are spinning and when you apply a big force on the pedal there is a lot of resistance to push into.

Now the first thing I need to do is calibrate my Assioma pedals to show the same power as the TrueBike, at first glance it looks like there is a 2-3% difference. Unfortunately the Truebike gives lower power than my pedals. Will calibrate to the TrueBike for practical reasons, but also because they claim it to be 0.1% accurate .

Here are some specs:

  • Build-in rechargeable battery, regular usage is enough to keep battery charged with no need for external power.
  • Two ride feels: TrueBike and Spinbike. With Spinbike it simulates how a regular trainer would feel like.
  • Three ride modes: Road / Power / Control. With Road, you can choose the incline and it simulates the resistance accordingly. Power is a ERG mode with set power, still need to test more, but it looks like for what ride feel is concerned it functions a bit like the Kickr in ERG mode: shift to high gear for riding on flat and low gear for riding on an incline.
  • 12" display in front of you that you can control with the keys on the handlebar. All the regular data can be shown like power/cadance/speed/gear/HR, both as a numeric value and in a graph. There is also a polar plot of the resulting torque applied to the crank.
  • I can use the Garmin computer to ride a route and it will adjust the incline according to the route. It also connects to Zwift and Trainer Road, allowing it to be controlled as usual.
  • I still need to have a tablet or phone for the workout details in TR. During the workout, the TrueBike screen shows the target power, current power and a graph of the historic power. But it does not show things like future target power or how long the current interval is.

These are some reviews of the early version:


This sounds all great and stuff. And for sure I applaud every start-up that increases competition in the industry and gives us consumers more choices.
But I have to say

is a pretty bold statement to put it mildly. To me indoor rides feel like indoor rides because I’m indoors lol. How the bike/trainer feels it’s kinda secondary. I will never get over the fact that I’m in my living room enclosed by walls and a ceiling. Not moving a cm in any direction.

Other than that it looks like a pretty neat piece of equipment. :+1:t2:


what’s the approximate cost of this wonderous new invention?

It is in line with the Neo Bike and the Wahoo Bike. EU price is EUR 3250

Yea, it is not Startrek Holodeck experience yet. :smiley:

I think if you want to nitpick on marketing claims, I would go for their claim that on “regular” trainers you can output up to 20%-30% less power than outside. That is not the experience I have with the Kickr, differences seem much smaller than that. Although it looks like that is no longer mentioned on the site. They refer to a few articles and now only mention there being a significant difference in power production.

Haha wow. Definitely not shy about the marketing. That would be pretty Bananas. Like, your FTP is 300 outside, but suddenly you would struggle to hold 200 indoors? eeehhm no. I don’t have a power meter atm so can’t say personally if I see different numbers indoors vs. outdoors. As far as I heard form others, it’s rarely more than maybe 5 %

Nonetheless, it’s an interesting angle. Although as far as I’m aware the reduced power indoors is mostly down to cooling and maybe the mental aspect. Not sure if an extra swanky resistance unit would help much in that regard.
But I understand how products need to try and distinguish themselves against others. Especially if you have to go up against well known established companies like wahoo.

The 20%-30% claim is from the articles they refer to, but I think that is talking about comparable RPE and also it is with untrained people that are not used to cycling in general.

Anyhow, I will be able to post some figures soon. Next Monday is my scheduled ramp test going from SSB2 to Build. I will be able to do the ramp test twice using the TrueBike mode and using the Spinbike mode and see what happens.

1 Like

Cool bike… But does it have rocker plates and the thing to change elevation?

I get the price to build things like this. But why would I pick this over a $2k, a $1k trainer, rocker plates and the elevation change thing?

At the end, indeed more value in getting a nice 2k bike that I know I can use outdoors, and not just feel like I’m outdoors

No Kickr climb thingy included here.
There is build-in side to side play that you notice when standing and pushing hard.

Outside bike on a fixed trainer puts stress on the frame that is not designed for. I guess rocker plates solve this a bit by reducing the sideways stress on the frame, but it still feels like those delicate bikes are being subjected to forces that you don’t get outside.

It sounds like the principle question here is the fixed indoor bike vs outside bike + trainer. The fixed bike is more expensive and requires more space, depending on how much of constraint that is, it might already leave you no choice. And it is for sure not a punishment to train on a nice indoor trainer like the Wahoo or Neo.
I like the convenience of a dedicated device, no metal parts that you have to protect from salty sweat, no fiddling with maintenance of chain / changing cassettes, less maintenance as indoor bike is more robust, easier to adjust to various riders.

As for the value that this bike has from better ride feel. That is really best experienced by trying it out. There is a noticeable difference and when I set it to spinbike mode it really feels like the Kickr. Curious to see how a ramp test works out, but will wait untill Monday as this is still my recovery week :smiley:


Fair point about having a nice bike on a trainer.


A cheapish aluminum bike from bike direct…

Then splurge on a trainer/trainer accessories and you will not get to 3500€

Look. I do like the bike. And I think eventually specific bikes like this will over take the high end trainers because they will be more sturdy than any bike out there.

My issue right now is pricing and value proposition. I find no value on a bike like this at this price point.

I do like the idea that it can be used by more than one person by changing sizes, but thats an edge case.

I do get that a startup, is making a bike like this at this price. It is not cheap to put together, specially if the yearly output is just 100 bikes. The margins are not there to make this bike a real competition in this market.

I wish them the best and I am certain their will find good home to all the bikes they build. Sadly I am not the target audience. I would rather use than money to get a real bike and use a trainer. But that me.

Let revisit this in a few years… I might have changed my mind.


I don’t see the advantage of no-flywheel systems like the Neo other than shipping / handling weight. The feel just isn’t there as the pedal stroke is too consistent, taxing your off-areas too much and going too easy on the stronger portions of your stroke (a more balanced stroke is better, perfectly even is not). I think for the price vs well known competitors, this is a huge swing and miss - unless there is some niche market for people who don’t have power/ do have an internet connection / need lightweight (corp jets/yachts???).

I don’t understand what you’re saying with “the feel isn’t there”?

1 Like

Electric controlled resistance always feel like you’re riding through mud or up a steep hill. The trainer does a crappy job with your pedal stroke surges and wanes, as well as power changes (zwift type rides).

When you think about the current trainer resistance tools, you’ve got flywheels (inertia) and a brake of some kind- usually magnetic. You are delivering uneven power to the trainer.
The flywheel resistance is controlled by physics and the properties are set during the design of the unit by the weight, placement of that weight, and gearing of that flywheel. The flywheel responds INSTANTLY to any resist any increase in power application (ramp up); it does not provide much resistance in steady-state power; and just like a bike does when you quit pedaling on a flat or downhill road - it keeps spinning (ramp down).
The brake is a ‘hand’ that grabs that flywheel trying add additional resistance. It does this to compliment missing flywheel resistance to acceleration, mimic steady state resistance to wind/rolling resistance, to mimic hills, and to better control the flywheel for intervals where you want to go from high power to low power quickly. .The trainer also doesn’t know how much force it is grabbing with because that friction level keeps changing (flywheel rpm sensing lags, flywheel temp, resistance unit heat, humans lack of rhythm,etc ), so every action is done in steps. It responds rather slowly in the scheme of things (lets call that 2-3sec to arrive at the desired resistance)

The magnetic resistance unit can to most everything well except manage quick ramp ups and uneven power application. The flywheel is good at managing quick input changes and letting the strong parts do the hard work/the weak parts do what they can. So, we’ve got the the weighted flywheel here to manage the short term surge, the brake controls the median and target resistance, and the flywheel overcomes that resistance to manage the short term wanes.

(I’m lumping this in with the Neo, as I haven’t tried this)
The Neo and this are using (nearly) 100% magnetic-braking resistance without any flywheel inertia.

  1. The electronic units need to guess your surges and wanes.
    a) The Neo has a “virtual flywheel” function. It guesses what you’re going to do and then adds/lowers resistance mid-stroke with your rhythm , but it’s very aggressive / not responsive to unpredictable or momentary lapses of power application.
    b) Because of a few factors, the trainer can’t react effectively to control resistance at the “micro-stroke” level - again flywheel (resistance wheel here) rpm sensing lags, flywheel temp, resistance unit heat, humans lack of rhythm.
    c) It’s kind of wrong most of the time. It’s either over releasing/grabbing (more digital feeling spin) or under (more muddy feeling)
    You can highlight this… Go for a zwift general ride, where are you cadence numbers? how taxed are you given your output? Your flatland cadence numbers are likely going to be closer to your outdoor numbers on the flywheel trainers, your power number may be higher (because the flywheel on the trainer isn’t as pushing as the real world); it should be lower on the Tacx Neo (because you’re going to mud or it’s beating up your weaker muscles).

  2. The weighted flywheel is better as resisting ‘instant’ power applications and maintaining “momentum” over temporary lapses in power.
    a) You’re body is not built to ride a bike, you’re never going to have, nor to you want to have, a perfectly balanced circle on the graph above - this would mean you have insanely strong hip flexors and you’re under utilizing your thigh muscles.
    b) You need something to control the ‘surge’ of your big muscles and work with the wane of weaker ones.
    c) On a big acceleration, a magnetic resistance is going to be all over the board; the flywheel controls that ramp rate much better. It’s going to screw up the general ramp rate and changes in cadence rhythm. The Neo will actually “Slip” as it guesses the resistance change wrong and reacts to it.

You can highlight this… try doing an all out 10sec sprint on a lighter inertia flywheel smart trainer ( it’s tough to tell just by weight, because gearing and flywheel MoI matter, but the Zumo should be the lowest), then a Saris H2 or H3, and then a Tacx Neo. You’ll get a way better impression out of the H2/3 and higher power numbers.

Net… What you end up with here is a trainer that is good for training/punishing your body to ride up steep hills and mud, but not simulating flat land resistance. It can work great for stead state if you’re pretty rhythmic. If can work great if you’ve got a trainable weak point in your spin…or encourage you to make it worse improving areas that won’t translate to performance outside. This is the same for light smart flywheel trainers, but they don’t cost $XXXX and aren’t trying to play games with the resistance unit.

1 Like

Ok, let me first summarize your point before responding:

The resistance on a trainer comes from the flywheel’s resistance to change in speed and the magnetic break.

Flywheels on trainers typically have too low inertia. So a trainer with only a flywheel plus constant magnetic resistance feels too much like riding uphill or through mud.

A trainer with a small flywheel plus smart magnetic resistance can not solve the lack of inertia as the controllable resistance is never going to be fast enough in responding to micro changes in force through the pedal stroke, to resemble the response of riding outside on a flat.

Does that sum it down?

So it works similar to STAC Halcyon/4iiii Fliiight?

I don’t think so.

4iiii - AFAIK, this “pulses” the width of the magnets to apply and release the brake at specific levels and intervals to simulate what a heavier flywheel might do. It only changes the actual resistance level and offers no “propulsion” that can rotate or accelerate the wheel.

Neo for reference - The Neo is more like a motor/brake combination. It actually can propel the axle forward, as well as apply resistance to slow and stop the wheel. It does the “propel” function at specific settings to simulate the rider weight for a “virtual flywheel” effect rolling on a specified road. Then it can apply a braking force on top of this to slow appropriate to the conditions

TrueBike - AFAIK, this works more like the Tacx Neo models. Not sure exactly, as I am reading between the lines, but I think this is far more complex than the 4iiii resistance unit concept.


Hadn’t heard about the 4iiii Fliiight before. In principle it is all using the same concept of regulating how much electricity is generated by having coils move past magnets. Both the Neo, TrueBike and this 4iiii trainer, have no flywheel or a very small one.
In the case of 4iiii it looks like the rim plays the role of the coil and the trainer will adjust the distance of magnets to determine how much force is applied.

In the case of the TrueBike it is an actual electric motor that is in there and it brakes just like an electric car brakes. So it works electronically rather than actually moving magnets closer or further. I guess that allows for much more accurate adjustments.

Another difference is in how strong the forces are the electric motor can apply. I have just tried on my bike to make it spin, but could not. I set the incline to 15% and on the lowest gear I went all out reached over 1000W as my cadence span out but no slipping.

And the biggest difference is in the software that governs all of this. I know in the case of the TrueBike, the company is primarily a software company and their uniqueness is mostly in the software that manages the braking forces.

Here is the test I just did: - TrainerRoad

First sprint is in regular mode, simulating a low inertia trainer. It took me 3 seconds to go from cadence 75 to 127, I reached 1006W and when I backed down it was because I had spun out.

Second sprint was in the “True” mode. Same gear as before, but now it took me 6 seconds to go from cadence 77 to 122 maxed out at 1228W and it felt like I backed down because I was toast. All of this felt very natural, it was much harder to accelerate than the first time.

Then in the third and fourth sprint I tried out a slope, first slope of 10%, but I span out too fast, than I went for a slope of 15%. The interesting thing with sprinting on a slope is that there is much less resistance to the increase of cadence. On a slope the required power just grows linearly with speed, while on a flat it grows much faster. Result is that it took me just 4 seconds to go from cadence 42 to 149 and spin out. I reached a max of 1031W and could not feel any slipping, again a very natural feel to the resistance offered.

1 Like

Yeah, I’m basically saying that the electric brake alone works well enough in theory, but doesn’t have all the tools it needs to do it’s job well in execution. If the goal is to work out, it’s fine. If the goal is to increase outdoor cycling performance, it is not as good as similar priced competitors (though offers other benefits in trainer form).
The draw back is that the flywheel, even the limited size ones, handle acceleration and a more natural pedal stroke resistance better. The reason is that it can’t read your detailed pedal cadence and it can’t “bite” with the right amount of resistance repeatedly - causing unnatural steady state and accelerating resistance problems.

yes… with the detail that a motor, a generator, and a resistance unit are basically the same thing. Here Tacx has "electromotor containing 32 precisely positioned magnets that rotate around 30 coils. ".

So each coil can probably only activate in 1-2 “levels”, they probably work in groups (maybe 2 groups of 15 or 15 groups of 2), and they probably ‘strobe’ on/off if that doesn’t give them enough resistance detail.

The STARR / 4iiiiiiiiiiiiiiiiiiiiii trainer uses the rim as the flywheel… and there’s no inertia - likely less than the Neo. You’re not buying it for road feel experience though. Eddy current brake - Wikipedia

1 Like

In my post above I posted a ride I had just done where I tested a couple of all out sprints. Using the True mode, there was considerable more power needed compared to the mode where it simulates a trainer with low inertia. And it therefore took me much longer to spin out.

I even tried to make it spin, like the Neo did, I had read that it happens mostly on inclines in low gear. So I set it to the highest incline of 15% and in the lowest gear of 34x32. And went for an all out sprint from cadence 42 to 140+. Could not get it to spin or feel unnatural.

I used a Kickr Core before and there is a huge difference, with the Core it is like you can very easily push through and the pedal accelerates down very fast, while with this bike even when you stand, there is a considerable amount of resistance when pushing the pedals down.

I went from a Neo to a Kickr. My experience was that the resistance felt very similar. The only difference was the inertia. Neo is superb in that aspect.

1 Like