Zen Photon Ultra - limited version (Bafang Ultra, Rohloff Speed hub, Gates belt drive)

[Ravi Kempaiah]

To this wonderful EBR community, we wanted to let you know that our team is building a few units of this very special bike - Zen Photon 'Ultra'.
This E-bike is based on our Zen Photon platform but uses the Bafang Ultra motor and Rohloff 14-speed hub along with Gates belt drive - hence the name "ultra". Our custom Zen motor is powerful enough but some folks wanted to make use of the generous 750W limit offered in the US.
If anyone in the EBR community is interested in this high-power build with the Ultra motor, Gates belt, and Rohloff speed hub, please reach out.
We have already received a few deposits and it would only make it easier to build more units in this batch. We are only taking deposits and the remaining amount will be paid before the shipment leaves Canada.

This E-bike is going to be a very powerful rig, not for someone looking for a light weight E-bike. Someone who wants super heavy duty, long-range rig. See key specifications below:

1. Bafang Ultra - 750W (legal), 1000W (off-road version)
2. Rohloff 14-speed hub
3. Gates belt drive
4. 1040 Whr battery (52V, 20Ah) - UL certified battery (from true UL agency, not a 3rd party tested)
5. 4-piston brakes
6. Air-suspension, 15x110mm front wheel with Boost spacing, Zen custom suspension seatpost
7. There is always a special connection to the EBR community, and the price of this rig is going to be very competitive with anything else on the market.
   
   An engineering rendering is attached below. We are waiting for the UL-ceritification of the battery to be completed in the next 30 days.
   
   
   

 

[scrambler]

Nice!
I will take one with rear suspension

 

[ElevenAD]

OH Man this is going to be a fantastic bike!
Price?

 

[opimax]

Sounds like agreat bike , is the shifter a twist or electric?

 

[Poppyoppy]

I would be very interested in purchasing this bike , can you get me contact info for specifics
Projected cost ?
Deposit required?
Email me

 

[scrambler]

You should not give your email on a forum, this is a recipe for disaster....
Scammers have bots gathering these automatically.

Use personal messaging from the forum instead.
You should edit your post and remove it.
My 2 cents

 

[Poppyoppy]

thanks
not very computer literate
i think i was successful in removing

 

[ericcow]

Good day to all. Are there any updated photos for the Ultra either here or the website?

 

[Ravi Kempaiah]

Good day to all. Are there any updated photos for the Ultra either here or the website?

These are some images of the Ultra bike soon after assembly at our factory. you will notice the suspension forks are top of the line - Titan model from RST.
These frames arrive in SKD condition and then go through the final QC/QA in Canada. These frames are expected to arrive in Canada towards the last week of March.

 

[JGcycle]

These are some images of the Ultra bike soon after assembly at our factory. you will notice the suspension forks are top of the line - Titan model from RST.
These frames arrive in SKD condition and then go through the final QC/QA in Canada. These frames are expected to arrive in Canada towards the last week of March.

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Where can I get handlebars like these?

 

[Ravi Kempaiah]

Where can I get handlebars like these?

We can get you one. This is what we use on our photon Pure E-bikes.

 

[Ravi Kempaiah]

Perhaps we can make use of some suggestions from @smorgasbord and @Gionnirocket to tune the motor to be as smooth as possible.

 

[Gionnirocket]

Perhaps we can make use of some suggestions from @smorgasbord and @Gionnirocket to tune the motor to be as smooth as possible.

Sure Rav'.. you're more than welcome to my .el file.
One issue that comes to mind is that I changed the display to the 860c so that I now have 9 PAS. Where as the stock DPC18 has 5 PAS with Eco/Sport modes. So we'd have to review/tweak it as I believe Eco maps to PAS 1,3,5,7,9 and Sport to PAS 2,4,6,8,9 if my memory serves me. That said I do feel my tune is better (for me) than what was received. The stock tune acceleration curve when compared to input pedal pressure felt flat at the beginning and too aggressive at the end. Also understand my tune is set to my needs and expectations which can be somewhat personal....My main reason for wanting a UART Ultra.
Let me know if you want to run some tests.

 

[smorgasbord]

This looks like a great bike. I'm going to assume, given general layout and tires, that's it's intended for paved road/trail or easy/wide packed dirt trail use. Then, if it is indeed a Uart Ultra that can be tuned:

1) My first, perhaps outlandish, suggestion would be to employ my double-fake-magnet scheme, if you can. That is, as the bike's OEM, you should have access to the Bafang BESST tool and can program in a custom wheel diameter on the display (which looks be a DPC-18) to be twice the actual diameter while telling it that the bike has 2 wheel sensors, but it only has 1 (thus making the MPH read true on the display). This will enable a Torque Tab tuning range that covers 0-25 MPH rather than the Bafang default of 0-12.5MPH. The only display I know of that can do this trick in stock mode is the EggRider, but given it's a very small display I can see why you wouldn't want to ship that standard on the bike.
Expanding the Torque tuning limit from about 12.5MPH to about 25MPH opens up all sorts of possibilities for tuning. When everything above 13MPH is forced onto the same SPD100 column for tuning, you have to make compromises.

2) Measure a few of the early samples of the Bafang Ultra to see what Base Voltage they output when at idle. The procedure is described here and here. You can use an EggRider or the Window app opened to the Delta Voltage section. Putting in the highest Base Voltage of the samples you see (maybe add 1 or 2) will ensure that riders get a smooth response when they start pedaling

3) Also in that Delta Voltage procedure is how to adjust to Torque to Current mapping to be reflective of how humans apply energy, which isn't linear. There's a Google Docs Spreadsheet linked in that post. It's currently got a 100%-125%-150%-175% curve, but you can adjust those numbers (I personally run even steeper) in the spreadsheet if you download it. This is also where "smoothness" comes into play, having the assist start lower so the bike doesn't jerk out at startup.

4) Finally, the easy thing to do that every OEM should do is setup the PAS ranges to be linear-percentage-increases, not linear-power-increases. On your 1000 watt Ultra, for instance, going from 100 watts to 200 watts is a doubling of the max power being applied and is very noticeable. However, going from 850 watts to 950 watts is almost imperceptible. So, don't space the current values evenly, instead do something like as is described in this post. Some details for how to go about decided are in this post.

I think it would be exciting to have an bike tuned by the OEM to take maximum advantage of the Ultra motor, as no-one does that today.
Too bad you're not near Monterey, CA - I'd be happy to get together and try some things out.

EDIT: Corrected/clarified the double wheel magnet thing is in the mind of the display only.

 

[Gionnirocket]

This looks like a great bike. I'm going to assume, given general layout and tires, that's it's intended for paved road/trail or easy/wide packed dirt trail use. Then, if it is indeed a Uart Ultra that can be tuned:

1) My first, perhaps outlandish, suggestion would be to employ my double-fake-magnet scheme, if you can. That is, as the bike's OEM, you should have access to the Bafang BESST tool and can program in a custom wheel diameter on the display (which looks be a DPC-18) to be twice the actual diameter while telling it that the bike has 2 wheel sensors, but it only has 1 (thus making the MPH read true on the display). This will enable a Torque Tab tuning range that covers 0-25 MPH rather than the Bafang default of 0-12.5MPH. The only display I know of that can do this trick in stock mode is the EggRider, but given it's a very small display I can see why you wouldn't want to ship that standard on the bike.
Expanding the Torque tuning limit from about 12.5MPH to about 25MPH opens up all sorts of possibilities for tuning. When everything above 13MPH is forced onto the same SPD100 column for tuning, you have to make compromises.

2) Measure a few of the early samples of the Bafang Ultra to see what Base Voltage they output when at idle. The procedure is described here and here. You can use an EggRider or the Window app opened to the Delta Voltage section. Putting in the highest Base Voltage of the samples you see (maybe add 1 or 2) will ensure that riders get a smooth response when they start pedaling

3) Also in that Delta Voltage procedure is how to adjust to Torque to Current mapping to be reflective of how humans apply energy, which isn't linear. There's a Google Docs Spreadsheet linked in that post. It's currently got a 100%-125%-150%-175% curve, but you can adjust those numbers (I personally run even steeper) in the spreadsheet if you download it. This is also where "smoothness" comes into play, having the assist start lower so the bike doesn't jerk out at startup.

4) Finally, the easy thing to do that every OEM should do is setup the PAS ranges to be linear-percentage-increases, not linear-power-increases. On your 1000 watt Ultra, for instance, going from 100 watts to 200 watts is a doubling of the max power being applied and is very noticeable. However, going from 850 watts to 950 watts is almost imperceptible. So, don't space the current values evenly, instead do something like as is described in this post. Some details for how to go about decided are in this post.

I think it would be exciting to have an bike tuned by the OEM to take maximum advantage of the Ultra motor, as no-one does that today.
Too bad you're not near Monterey, CA - I'd be happy to get together and try some things out.

EDIT: Corrected/clarified the double wheel magnet thing is in the mind of the display only.

I'm sorry but I have to disagree with some of your suggestions. I believe I've mentioned some of this in your thread, but I'll go thru it here for ease of reading.

1. I feel this is something that an OEM should not engage in. Other than yourself I know of no one that is doing this or feels it necessary. What ever is going on behind the scene in the controller the appropriate magnet and wheel size settings work just fine. I have smooth, even and predictable acceleration from 0 thru +30mph.
I know this is your claim to fame, but it seems like you went to a lot of time and effort to fix something that really wasn't broke. In any case... I feel this type of hack is best left to the end user and not for OEM.

2. This is a good thing to check but this seems to be correct from the factory. As you suggested adding one or two isn't a bad idea.

3. I disagree that the full torque sensor output reading read from a standstill with full pedal pressure should be used.
(a) it's impossible to reproduce with the bike and pedals in motion.
(b) most of use using an ebike don't want to put that much strain on our knees during use anyway.

I suggest using the max voltage output matched to the maximum amount of pressure you want to exert. This can be obtained using the standard test method.
Or using approximately 80% of the max reading from standstill with full pedal pressure also seems like a reasonable place to start.

4. I disagree here as well. Using a percentage PAS mapping creates very small changes in lower PAS and large changes in higher PAS. Using a somewhat linear progression here gives equal and predictable increase with each PAS. Many times I need just a little more assistance and this makes the increase as needed and predictable. In the less often times that I do require a large increase, I can easily double or tripple tap in just a second. I like to get PAS 1 and 2 setup for slow low gear situations and then increase uniformly from there.

Not saying that your wrong and I'm right as much of this is personal preference.. but they don't work for me nor would I suggest them for an OEM to implement. In the end the lure of this motor is making it personal so no matter how received I would probably still tweak things.
ymmv...

 

[smorgasbord]

I feel this is something that an OEM should not engage in.

Well, that's up to Ravi, obviously. I did say it was "perhaps outlandish."

I know this is your claim to fame, but it seems like you went to a lot of time and effort to fix something that really wasn't broke.

Stop trying to make this personal. The facts are what they are. I've outlined a simple test procedure for anyone with an Ultra motor to verify my statements as to how the Ultra behaves with changes in the Torque Tab. As for not broken, I disagree - not being able to have different torque settings for anything above 13 MPH, while having 6 different sets below is broken, at least in my opinion. I think it's fair to say you haven't tried it, so you don't actually know how much better it could be. You're essentially running the SPD100 settings for all bike speeds above 12.5 MPH. That's apparently OK for you, but having the ability to tweak settings for different speeds above that for a road-based bike is good to have. I personally feel there's too much programming speculation and not enough isolated testing validation, and that has caused more than a few people to give up on improving their settings since they're essentially stabbing the dark.

This is a good thing to check but this seems to be correct from the factory. As you suggested adding one or two isn't a bad idea.

I don't know which "factory" you're talking about. Some OEMs ship Ultra motors with "0" for Base Voltage - I've seen that personally with at least 3 different OEMs. A few OEMs ship with 754mV or thereabouts. I agree that the non-zero default is reasonable. I've seen it postulated that the value of "0" causes the Bafang firmware to substitute some default value internally, but I have no way to actually test that. I have seen that putting in too small a non-zero value can make the motor a bit jumpy at stand-still, as the motor generating more than Base Voltage is apparently interpreted as pressure on the pedals.

I disagree that the full torque sensor output reading read from a standstill with full pedal pressure should be used.
(a) it's impossible to reproduce with the bike and pedals in motion.
(b) most of use using an ebike don't want to put that much strain on our knees during use anyway.

I do cover setting up a Delta Voltage table for a less than 60kg max applied pressure in my posts. Also, I did run a live test while riding my own bike using my EggRider and my phone's screen recording capability, and I was surprised to find that I'm apparently a much strong rider than you are , as I did hit maximum voltage (from 60kg) a few times during that ride.

4. I disagree here as well.

Luckily, changing PAS levels is the easiest thing to program on a Bafang motor, so people can try it out for themselves.

 

[ericcow]

Hi to all.

It appears that this bike will at least have the option for a throttle, or will that come standard? And will there be an electric shifter option for the Rohloff also? Cheers

 

[Gionnirocket]

Hi to all.

It appears that this bike will at least have the option for a throttle, or will that come standard? And will there be an electric shifter option for the Rohloff also? Cheers

Throttle yes but I don't believe the e shifter is compatible with Bafang at this time.

 

[Ravi Kempaiah]

as Gionni mentioned, the bike has a throttle (actually, we have improved the throttle hardware from what you see in the picture)
and the Rohloff E-shift is only limited to Bosch and Panasonic motors. As of now, no other motor works with Rohloff E-shift.

Hi to all.

It appears that this bike will at least have the option for a throttle, or will that come standard? And will there be an electric shifter option for the Rohloff also? Cheers

Our Bosch-motor equipped Samurai works with Rohloff E-shifter and dual battery, but on the flip side, none of the Bosch or Panasonic motors have a throttle.

 

[ericcow]

Thanks to you both Ravi and Gionni.