Boxxbike Valkyrie : 12kw crank concentric mid drive with left hand motor drive

[scrambler]

Everything is possible, as they say, where there is a will, there is a solution :wink:

That said, you would first need to qualify range and speed to get some idea of how much of a second battery you would need.

The battery compartment can definitely be opened to access connections. I have not done that yet, so I don't know how much space is there...
Swapping batteries on the go would not be quick as you need to unscrew several screws to open it
Having an external connection would just require to get the two big wires out to either a switch or a Y connector with Diodes (to use batteries in parallel), and back in. Then connect your backpack battery to it when you need.

That said, to push 8kW out of a battery requires a minimum size and cells and beefy wires (the farther you go the beefier they need to be).
The 1800 Wh I have uses uses GA cells and can do that with 12S-12P and it is a large battery to carry in a bag pack.

But as I said, the first would be to define range speed and type of driving to get an idea of what capacity we are speaking of...

 

[Enric]

My idea for the second battery is not to continue driving the bike with all its power, but to have a rescue battery for when the first one runs out, to return home with assistance and throttle, it would be enough with 1500-2000 w

I currently have an ebike with an Innotrace G510 with about 3000-3500w and on some routes I carry another battery in my backpack connected with a cable.

I have used it a few times, but when I have used it it has worked very well, and when I have not used it it has also given me a lot of peace of mind to get away from home knowing that I will have a battery to come back.

 

[scrambler]

That makes more sense then.

 

[Cozen89]

I’m really interested in this bike. Checks a lot of boxes for me. How’s the acceleration/speed compared to something like a surron?

 

[scrambler]

This is more powerful than a standard Surron

I think the standard Surron is 4kW, this is 8kW...

In highest level you cannot gun the throttle, or you will flip over

And they recently have lowered their prices quite a bit, although shipping cost has exploded....

 

[Cozen89]

This is more powerful than a standard Surron

I think the standard Surron is 4kW, this is 8kW...

In highest level you cannot gun the throttle, or you will flip over

And they recently have lowered their prices quite a bit, although shipping cost has exploded....

I just wish there was somewhere to see or test ride these things in person. I only ask to compare to a surron because those bikes are everywhere and I’ve seen and ridden a few. I know on paper, it has higher wattage rating, but also a smaller battery and lower voltage so just trying to figure it all out.

Also concerned on the height of the bike. I think somewhere on this thread, it was stated as 950mm at the lowest seat position.

 

[scrambler]

What drives the torque is the amps, not the voltage, this is partly why this bike's battery is 12S-12P

The bike is quite high at about 960mm minimum. You could probably cut off about 25mm of the seat tube if you know what you are doing.

 

[Cozen89]

What drives the torque is the amps, not the voltage, this is partly why this bike's battery is 12S-12P

The bike is quite high at about 960mm minimum. You could probably cut off about 25mm of the seat tube if you know what you are doing.

How many amps is it pushing? Sorry if this was mentioned in the thread before. I read through it but I might’ve missed it.

 

[scrambler]

The 1800Wh battery that came with mine can do 43V x 180Amps, but if I remember well, the Silixcon controller is set to allow conversion up to 360 of phase Amps.
Of course to do that the controller would have to cut the voltage in two, as the 1800Wh battery using SAnyo GA cells can only output 8kW at peak (180A x 44V)

 

[sn0wchyld]

What drives the torque is the amps, not the voltage, this is partly why this bike's battery is 12S-12P

The bike is quite high at about 960mm minimum. You could probably cut off about 25mm of the seat tube if you know what you are doing.

Just for clarity - its Phase amps that drive torque, and they are more or less isolated/separate from battery amps (or rather, are only limited by battery power).

@ Cozen:

I have both, the stock surron is definitely a bit slower than my box in terms of torque/acceleration, though it does have a higher top speed (my boxx is limited to ~50km'h, i only opted for the 12kw version).
The surron with an aftermarket controller starts to become more competitive, though my surron still has a stock battery so Im limited there. Basically the box and surron (with new controller but stock battery) would be fairly close off the line, the box would pull away for a bit, and then the surron would pass it back due to higher top speed. Stock surron the box would win off the line too.

Height wise, for me (at 6''1'), the box is fine. I'd have the seat height a bit lower if I could but something to note is the pedal height is relatively high, so you dont feel 'stretched out' when actually riding it. Its possible to cut it a bit lower if it was a bigger problem, but no need for me. Also means it has much better ground clearance than the surron.

Only thing at the moment the surron has on my boxx is the higher top speed and the use of moto tyres (my rear bike rim on the boxx is getting pretty beat up, and I've had a few pinch flats even with liners). If I could find a very light weight 21'' mx to use on the rear of the boxx it'd be a match in heaven I think, though all the ones ive found are quite heavy.

Depending on where you are, you could take the savings form the cheaper surron price and upgrade it, and the performance gap $ for $ would be very narrow. at that point it comes down to wanting a small motorbike or a large pushbike.

 

[scrambler]

I agree, if one mostly wants to use the throttle, a Surron with an upgraded controller could be just as powerful, and more suited to the motorcycle riding position.

Personally, I want to use the bike as an EMTB most of the time, so having the BB with upgraded torque sensing pedal assist is way more interesting than the Surron.

 

[Cozen89]

Thanks for the insight. I’m pretty familiar with the surrons and the available mods and potential power output. But I’m not looking just for speed. I prefer some what of a do it all bike. Something I can pedal when I want, throttle and rip it when I want, and ride trails as well as street. So something like the boxx is very appealing to me with the dual drive train. I also prefer to fly under the radar a bit as well as stay light weight. Surron seems great for the price and available mods but it’s just not for me.

 

[scrambler]

If you want pedal assist in a very high power bike, BoxxBike is the only thing right now.

Soon you will have the Nicolai Eboxx Ultra as an alternative (although no actual pedal assist yet), and lower in power you have LMX (excellent pedal assist) and SEM (although no actual pedal assist)

 

[Lwing]

Hi Scrambler, just checking in to see how your kindernay conversion has worked out, still happy with all your mods, and the bike, anything else your looking to change?
Thanks

 

[scrambler]

More than happy

The Kindernay VII is great, I have a much better gear range now, and I can pedal the bike at higher speeds.
The seven steps are perfect, and I mostly use the top 3 or 4 gears (lower ones would be mostly useful in case of the battery going out and having to pedal without assist)
The bike is clean with no exposed derailleur

The torque sensor tuned with a low pass filter in the controller is great to use even on streets. I pretty much only use the torque sensing pedal assist now, and I can pedal up anything with it up to insane power

The regen on the front brake lever is amazing, set at twice the regen power of the throttle engine brake, I can recuperate a lot of battery on trails with a lot of climb (and therefore descent). I almost never use the rear brake anymore, except on very steep and tricky descents.
On street, I just feather the front brake to slow down and so even the front brake gets a lot less used.

Cant think of anything else to do for now

 

[Turbocake]

i think the 12s is due to the regulations for batteries over 50V... which in EU (afaik) is far more arduous because its the threshold for 'dangerous'... and at 14kw peak, dealing with the thicker wires from the battery is easier than dealing with the extra regs for 50+V systems. Doesn't make a difference to the motor so no real loss overall other than a smidge more copper weight.

But... got the bike this week

As to your other questions
Candice sensor isn't bad, and its got a ramp to the power so its ok, but the switch they were using to cut it out under breaks was apparently unreliable so they've removed it on the latest batch of bikes, much to my chagrin (didn't let me know beforehand). its good for a candace sensor, but still a candace sensor. also means no cut out / clutch for the moto modes, but honestly there I think its a liability, I hated that feature on the surron, as it was hard to know what % throttle you were at when releasing the breaks, and it was like dropping the clutch at some unknown rpm.

few other niggles:

Q factor is quite big, around 300mm, and wider than the quoted 240. Should be able to help this a bit if i can find some 'straight' cranks that dont have the usual 'toe out' offset. combined with the relatively short stock cranks it makes pedaling a little weird. Not awful but not as nice to pedal as a 'typical' bike.

Bike is very tall, geometry more like a moto. im 6'1 and have the seat at its lowest possible height, and id still like it a bit lower if I could, though its not too bad now. will see how it goes but may end up chopping a bit of the seat stem.

Seating position too is a bit too far forward relative to the pedals. An inch backwards would be better, but not a huge problem.

The controller software has some bugs/nuances that they're still working on. Only one to affect me so far is that the motor/controller remains powered for a few seconds after turning everything off... so twisting the throttle can still make things move. Fine if you know its there, but if you didn't the bike could go flying with an accidental throttle twist.

Handlebars sit at around the height of my elbow, standing next to the bike, so quite high also. Feels pretty good on road though so not an issue for me.

For the cutout issue I'm going to chat to the guys about adding it in for the pedal modes, I have some MT5E's so getting a reliable switch is taken care of. I also kind of want a 2 stage switch so very hard pulls on the breaks do cutout the motor in all modes... not essential but a good 'oh shit' option if it can be added.

For the pedals, if anyone knows of some 'striaght' square tapers please let me know. Or if you know how to make your own square tapers I can give that a go.

For the seat, going to see how it goes for now and invest in a slightly lower profile seat stem that should gain another 10-20mm over stock. My discomfort here is likely as much due to coming from my old norko aline and a stealth fighter, both which ride quite low, so could just take some getting used to.

As to the bike otherwise, im pretty happy/impressed so far. been in the 8kw mode most of the time, as I am better suited to thumb throttles and the height and the 220Nm at 12kw makes for a wheely machiene.
:thumb:
feels faster than a stock surron, despite the peak thrust being similar (220Nm vs 200 for the surron, but with a smaller wheel) it puts out that thrust for longer/to a higher speed.
:thumb:
Bike is built like a brick shithouse, feels very solid, much more so than the surron (and defiantly more than the stealth). Feels like I could throw it around far more agressively before things start failing. Having the separate drive lines is a good backup too.
:thumb:
Control on the sixillion is nice, im no fan of full twist but Im finding it pretty controllable. The Magura throttle may be helping that too... They were happy to send me a spare throttle cable connector so I can switch to thumb and give that a go.
:thumb:
Chain noise isn't too bad either. Its there, but its not offensive. Quieter than the surron. I might look to convert to a belt drive, given you can still pedal should the belt go, for some real silent running, but not urgent.

Just curious if to lower the height of the boxxbike you may have ever considered swapping to 26” wheels or 21”mx rims?

I’m 6’1” as well and REALLY want one of these boxxbikes, but I am nervous about the height and overall size because I loved the size of the SurRon which most people consider small. I may be a bit taller, but I have a 31-32” inseam and am mostly longer in my torso/upper body. So if you have any advice please let me know, because other than size concerns, I absolutely love this bike and haven’t even seen one in person yet. Thank you!
I’m also considering adding taller handlebars for my back. Even if I look like a weirdo, I’d love to be comfortable on this bike, but without the look of a dirt-bike

 

[szkuba]

More than happy

The Kindernay VII is great, I have a much better gear range now, and I can pedal the bike at higher speeds.
The seven steps are perfect, and I mostly use the top 3 or 4 gears (lower ones would be mostly useful in case of the battery going out and having to pedal without assist)
The bike is clean with no exposed derailleur

The torque sensor tuned with a low pass filter in the controller is great to use even on streets. I pretty much only use the torque sensing pedal assist now, and I can pedal up anything with it up to insane power

The regen on the front brake lever is amazing, set at twice the regen power of the throttle engine brake, I can recuperate a lot of battery on trails with a lot of climb (and therefore descent). I almost never use the rear brake anymore, except on very steep and tricky descents.
On street, I just feather the front brake to slow down and so even the front brake gets a lot less used.

Cant think of anything else to do for now

Great project! and cudos for implementing torque sensing, that really makes the e-bike feel more like a bike . I made analog controll of torque few year ago and during my search for a Holy Grail of torque control went through many iterations finally getting to know Open Firmware projects for Kunteng controllers. The latest discovery was quite interesting to know as our torque we produce on pedals is dropping with cadence increasing so it must compensated.

source: https://www.researchgate.net/figure...ity-ie-cadence-and-power-output_fig1_49284193

Some use torque mapping with cadence speed and some are calculating pedal power. Personally i prefer combining both torque and power calculations as it gives best natural feeling. Just let me know if you are further interested in the topic of torque control or completely satisfied and don't want to change anything, which is also fine.

 

[scrambler]

Thank you for the info.

I know what I have at this point is crude (torque sensing only), but with the help of the controller low pass filters, I got to a point where I am happy with it.

Ultimately, I agree that the torque sensor signal should be combined with the cadence sensor, and power calculation should be made. LMX I believe has done that on their bike using the same Silixcon controller that is in the Boxxbike.
So if I was to go the next step, it would be to feed the Torque sensor signal into the Silixcon controller, and do the cadence / torque / power calculation in there, trying to get the programming that was done for the LMX. Silixcon unfortunately, although very helpful, does not seem to have a lot of resources evolving the controller programming.

May be one of this days I will work up the courage

 

[scrambler]

BoxxBike Second battery study

Note: Full resolution CAD drawings can be found at the link below
BoxxBike Second Battery - OneDrive (live.com)

A fellow BoxxBike owner in Europe is thinking of adding a secondary battery on the bike to extend range. Existing battery is a 12S-12P pack of 18650 Sanyo GA cells with a capacity of about 1800Wh.

His preliminary tests for space showed he could possibly fit a 12S-5P of the same 18650 Sanyo GA cells in the triangle.

To lend a hand I Modeled the Boxxbike frame triangle and did a bunch of simulations for different packs

First I looked into the various type of packs we could consider with two different types of cells.

• The Sanyo NCR18650GA cells used in my pack have a max continuous current of 10A, a capacity of 3.5Ah, and a diameter of 18.5mm
  18650 GA cell, Dia 18.6mm: Best case scenario, 50 Amp and 756Wh
  12S x 5P : 10A x 5 = 50Amp; 3.5Ah x 5 = 17.5Ah x 43.2V = 756Wh
  12S x 4P : 10A x 4 = 40Amp; 3.5Ah x 4 = 14Ah x 43.2V = 605Wh
  
  
• The 21700 Samsung 50S cells have 5Ah of capacity, and 25 to 45 A of max continuous current, for a diameter of 21.25mm.
  21700 Samsung 50S, Dia 21.25mm: Best case scenario, 100 to 180Amp and 864Wh
  12S x 4P : 45A x 4 = 180Amp; 5Ah x 4 = 20Ah x 43.2V = 864Wh
  12S x 3P : 45A x 3 = 135Amp; 5Ah x 3 = 15Ah x 43.2V = 648Wh

Choosing a pack depends on how one plans to connect the two batteries.

• He is thinking of connecting both in parallel to the controller, in which case the 12S-5P of 18650 cells is probably the best choice (same cells charge and discharge curves).
• If the two packs were supposed to be used sequentially (with a switch), the 21700 12S-4P pack would be the best as it can deliver as many amps as the existing 12S-12P 18650 pack and has a bit more capacity.
• The 21700 pack could also be good if it was OK to connect it in parallel with the existing 18650 based pack.

Question: Does anyone have experience with connecting an 18650 cells pack and a 21700 Cells pack in parallel?


I did some research on paralleling different capacity packs, and below are some video that may be of interest.

• Fairly proportional discharge test
  
• Not so proportional
  (2) Mixing Battery Capacities Parallel Discharge Test 100ah & 200ah Lithium SOK & Roamer - YouTube
• Low discharge and charge, fairly proportional
  (2) Parallel connecting Lifepo4 batteries of different brands and sizes! Extreme Parallel Part 1! - YouTube
  (2) Parallel charging Lifepo4 batteries of different brands and sizes! Extreme Parallel Part 2! - YouTube
  (2) Discharging Lifepo4 batteries of different brands and sizes! Extreme Parallel Part 3! - YouTube

Now as far as Space, it is definitely tight in there for both types of packs.

He is using the bike as a motorcycle, so he is not using a dropper post, and could therefore cut the bottom of the seat tube, gaining some precious space. With that extra space, and his Cane Creek DB coil that has a single adjustment Knob, he should be able to fit the 12S-5P of 18650. A simulation using 19mm diameter for the glued cells shows enough space.





I am using the bike as an e-MTB and pedal assist, so I use a dropper post and therefore cannot cut the bottom of the seat post. In order to gain some space, I would need to check if my Shock could be installed in reversed. I have not tried yet, and it may not be possible as my Rockshox Vivid has two adjusting knobs that may interfere with the rear triangle mount…





One element that would help, would be to know the exact dimension of several row of cells glued together, in order to know what apparent diameter to use for an accurate simulation.
So far I used 19mm for the 18650 cells of 18.5mm, and 21.5mm for the 21700 cells of 21.25 mm …

Question: Does anyone have real life dimension for rows of these cells glued together?


Assuming either of these can fit, I made some preliminary 2D and 3D models of the BoxxBike frame and the Battery Box below

Initial models had the box coming into the right, but reversing it to make it come into the left allows us to use the two screws of the existing battery cover to increase attachment to the frame. The Box also has a brace attaching to the top tube, and two ears screwing into the rear vertical plates of the frame, or extending behind them if we don’t want to drill the frame plates (which I think is fine). The cover and the box have bottom lips that hug the frame to keep it in position.









Now just to get an idea of the cost of 3D printing such a box, I generated STL files of the box and cover, and submitted them to a couple of Online 3D printing services like Xometry and Scuplteo. The quote I got was quite expensive for the standard (although very resistant) Nylon 12 material. The box comes in around $200 and $300 and the cover between $100 and $150…

Question: If anyone knows reliable 3D printing services with affordable prices in Europe and in the US, please do not hesitate to share.

Of course there will be several things to validate before finalizing a design, such as:

• Actual dimension of glued cells
• Final pack design with BMS size and cable size / routing
• Place to make the connection between the two packs to determine entry point in the frame, and finalize cables exit on the box.

Feel free to chime in

 

[Wazzaaaa_x]

Good morning,

i have got myself a boxxbike valkyrie, all black 14kw, Rockshox suspension. Would anyone be kind enough to know who would have experience on repairs/service with these bikes? Im in the UK, south west, can travel.

Its really just for future reference, my particular bike seems to have a abnormally loud chain and sprocket, its also eating away at the rubber tensioner. Is this normal behaviour? Cheers!

 

[scrambler]

Have you tried a video conference with Boxxbike support, they are usually very helpful.
But if you have a a chain issue, any motorcycle shop should be able to look at it in case something is out of alignment.

 

[Wazzaaaa_x]

Have you tried a video conference with Boxxbike support, they are usually very helpful.
But if you have a a chain issue, any motorcycle shop should be able to look at it in case something is out of alignment.

Boxxbike have been very helpful, they ended up shipping me the 2023 sprocket and new chain. Did the change myself with them on call and it seems to have solved it very easy and nothing to report again. Cheers

 

[Boombastik]

I just want to take a minute and thank @scrambler! You are a great community member here. It's been awhile since I have purchased a new bike, and its not an easy thing to do with all the options out there. You took a lot of time and helped me a lot. The bike has been built and look forward to riding it when it gets home!

 

[scrambler]

Looking good, I see you went for the satin black, good choice

Lots of fun in your future ...