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[rgutt]

There are some pretty old topics about adding a regen lever. This is about the same but on a much newer model. I've got a 2021 SR on which I would like to replace the rear brake caliper with a pressure transducer to feed an analog input for variable regen on the Sevcon. In theory, this would allow the Bosch anti-lock brake system to continue to work on the rear "brake."

I have two problems, the first of which is pretty easy to overcome as long as I can address the second. After 2015, the throttle went to a dual signal system, so both analog inputs on the Sevcon are being used. I'm going to have to convert that back to a single-input system (at least from the Sevcon's perspective), which is how all of the previous bikes were anyway. I might one day wire in my own chip to monitor both signals from the throttle, but really, throttle failure to 5 volts is my least worrisome failure mode. Anyone who's ever lost power on an onramp, on the highway, or just in traffic in general knows that failing to 0 throttle isn't necessarily any safer than failing to 100% throttle, and at least in the case of the latter, one can still maneuver and use the kill switch to shut down.

My second problem and related to solving the first is reprogramming the Sevcon. I've contacted and am awaiting responses from two companies I see selling the latest IXXAT USB-to-CAN converter. I'm not keen on dropping nearly ~$800 on something I'll probably use only once, but I'm even more reluctant if the license could theoretically not be renewed in as little as a year. On the other hand, I see many references to the V1.5 and 1.6 versions of the same device. I was able to find a link to the old software thanks to this site and the drivers that should supposedly let it function on windows 10 & 11. I can open the software, but without the USB-to-CAN converter, I really don't know if it's going to work. The only V1 devices I see for sale are >$600 out of Germany. For that amount, I might as well try harder to get the V2 device, especially since I can't say for certain the program I have will work.

And then there are the handheld programmers that I see a few companies offering to rent for ~$75/week. Assuming all of the parameters to which I need access are available, that would get me where I need to be for probably under a couple hundred unless I ran into trouble. As I have a job, if something goes wrong or I need more development time to tweak the parameters to my liking, I can't really put all of my time into this.

Does anyone have any recommendations on direction or an available programming cable for that matter? I'm located down in Louisiana.

[NEW2elec]

Why would you want to do this?
What people have talked about before, myself included, was having a regen only left hand lever but keeping the rear brake caliper and brake pedal.

Are you saying remove the whole rear brake assembly and only having rear regen?

[rgutt]

When I wrote that all of a few hours ago, yes, that was the plan. But on retrospect, I would keep the mechanical rear brake present if only to satisfy the legal requirements of a brake on both wheels. That does change my overall plan but is ultimately irrelevant to my question.

As for the solutions people have used in the past, I don't want a regen lever that is the same place as the clutch lever on my ICE bikes, nor do I want the regen triggered off a release of the throttle (I think I've seen it referred as the Vectrix throttle). If I wanted either of those solutions, I'd have started with them. That's not to say that in the end I won't go one of those two ways, but it's not what I'd prefer.

To more directly answer your question of why, the short answer is because I can. On my ICE bikes, I engine brake all the way into corners and rarely use my mechanical brakes except to stop at a red light or jack rabbit a stop sign. I do the same thing in my car albeit with more use of the brakes. I'd just like to be be able to operate the electric bike in the same manner.

[NEW2elec]

When I wrote that all of a few hours ago, yes, that was the plan. But on retrospect, I would keep the mechanical rear brake present if only to satisfy the legal requirements of a brake on both wheels. That does change my overall plan but is ultimately irrelevant to my question.

Well that's why I asked because the idea of removing your rear brakes completely was too crazy to go any further.

As for the solutions people have used in the past, I don't want a regen lever that is the same place as the clutch lever on my ICE bikes, nor do I want the regen triggered off a release of the throttle (I think I've seen it referred as the Vectrix throttle). If I wanted either of those solutions, I'd have started with them. That's not to say that in the end I won't go one of those two ways, but it's not what I'd prefer.

I have to make sure you understand that you can't have a go forward electric motor and an electric generator putting power into your battery at the same time, right?
You have to release the throttle to regen.  Have you set your throttle off regen to 100% on your app yet to see how that feels in your custom mode?  Most people wanted a regen lever to micro adjust speed to a given situation, while putting a little juice back into the battery because hey why not.

To more directly answer your question of why, the short answer is because I can. On my ICE bikes, I engine brake all the way into corners and rarely use my mechanical brakes except to stop at a red light or jack rabbit a stop sign. I do the same thing in my car albeit with more use of the brakes. I'd just like to be be able to operate the electric bike in the same manner.

Down shifting to slow into a curve serves two purposes both slowing you down into the curve and then being in a lower gear to have more torque powering out of the apex.
Electric doesn't need that.
For what it's worth the bike in my user picture has 43k miles on it and the original rear brake pads.  Just change the fluid every few years.
I think after you play with your regen settings either off throttle or using the front brake lever to just press in the brake light switch which will activate your braking regen without pressing the pads, you'll get used to the way it rides.

On a side note reprogramming the Sevcon will likely void your warranty so again I'd say learn to live with how the new bike behaves as it's the easiest path.
Good luck.

[ESokoloff]

You might trying configuring your Custom settings for 100% Brake on the Zero app.

For my 2016 DSR I have Speed, Torque, & Brake @ 100% & Regen @ 0%
This way when I roll off the twister grip I coast & if I want regen/back brake I apply light brake lever just enough to turn on brake light/regen.

Regen on my bike is not that strong but I’ve adapted.
I’m guessing you would miss mechanical rear brakes if removed.

[rgutt]

So far, no one who has actually made an attempt to answer my question. I am well aware of the adjustments available in the app and their effects on the bike. That is all irrelevant. I want information on the DVT software for the Sevcon ONLY.

And on that note, assuming anyone reads this far and notes the question asked, does anyone happen to know if Zero has started using passwords on the controllers? I noticed the old Sevcon manual makes no mention of passwords or user level access. Apparently, that "feature" has been added since they were acquired by Borgwarner.

[Demoni]

I have no idea if you could reprogram the Sevcon on your Zero to use the feature but the Gen4 Sevcon has this function.

Here is a link to the Gen4 manual:
https://www.thunderstruck-ev.com/images/Gen4%20Product%20Manual%20V3%204.pdf

This is taken from page 88:

Footbrake
The controller can use a switch or analogue voltage as the footbrake input. If a footbrake switch is
mapped, it applies maximum foot braking when the switch is closed. The footbrake switch object (2130h)
must be mapped to a digital input.
If the footbrake input is an analogue voltage, configure the voltage levels in the same way as the throttle.
The footbrake voltage (2221h) must be mapped to an analogue input.
Configure the characteristics of the footbrake at 2911h:
? Drive/foot braking priority. If the throttle and footbrake are pressed at the same time, this setting
determines whether the system attempts to drive or brake.
? Minimum speed for braking. Foot braking stops when the vehicle speed drops below this level.
? Footbrake voltage input and Input characteristic. These settings are similar to those for the
throttle.

[rgutt]

I'm not even sure how to respond to any of this. My first post asked merely for direction on the programming cables since I didn't want to drop $800 and possibly not have access to the controller settings. I was really hoping someone who of a magical source of V1.5 or V1.6 cables other than waiting for one to appear on ebay once every 6 months, or maybe even confirmation that the decade of DVT software would actually work with one of those cables should I manage to procure one.  I followed that up later inquiring as to whether anyone knew whether Zero had started applying user passwords to the controllers. But rather than get comments or answers pertaining to those direct questions, I have received comments on bike settings adjustable through the app, various reasons one might downshift, comments about brake pad life, and an excerpt from the manuals, NONE of which are relevant to my question.

Fortunately, I've found a contractor at work who has a Sevcon handheld programmer that I can wire into the bike, so I can find out directly what kind of access I can expect before having to drop the coin on a programming cable. I assume everyone has been trying to be helpful, but none of this was information I didn't already know.

[TheRan]

You probably would have gotten the answers you wanted eventually, they may even already be here in old threads. This isn't a terribly active forum and it's only been a few days. The reason for posts you have gotten is because those posters, as well as me, think it's quite ridiculous and unnecessary what you're trying to do. We're just curious about why you would want to do it. All I could think of is you want to save money on rear brake pads and reduce maintenance, which I could understand if the regen was actually strong enough to replace a mechanical brake.

[DerKrawallkeks]

@TheRan I can confirm that regen brake is strong enough to fully block the rear wheel if you want it to:)
I have a regen lever on my Zero S 2013, and I got a Sevcon DVT cable, but I'm located in Germany, and I have no idea if there's any passwords in the newer models.

[TheRan]

Under what conditions? I've ridden on some fairly slippery roads as well as wet mud and haven't slid the rear wheel using just regen. Perhaps older models had more, mines a 2019.

[ESokoloff]

Under what conditions? I've ridden on some fairly slippery roads as well as wet mud and haven't slid the rear wheel using just regen. Perhaps older models had more, mines a 2019.

4.5 years & 65k+ miles on my 2016 DSR with similar experience. 
Regen is akin to weak engine braking.
Nice to have to supplement, not replace rear braking.

[DerKrawallkeks]

@TheRan @ESokoloff
As I wrote, I have a regen lever:) this allows me to program (pretty much) any regen power that I want. Conditions don't really matter, it can be dry warm asphalt and it can still block the rear wheel (at not too high speed)

[rgutt]

@TheRan I can confirm that regen brake is strong enough to fully block the rear wheel if you want it to:)
I have a regen lever on my Zero S 2013, and I got a Sevcon DVT cable, but I'm located in Germany, and I have no idea if there's any passwords in the newer models.

Thanks for that info. I kind of figured regen would be capable of skidding the real wheel, not that I have any interest in doing that ... much.

I was able to get my hands on the handheld calibrator finally, and it looks like Zero hasn't started locking down the controllers. However, there are a number of settings that are rewritten by the MBB over the canbus at startup, pretty much all the values adjustable through the app and then some. I did find out that even though Zero wired both analog wires from the throttle back to the Sevcon controller, they didn't actually program the controller to use the second input. I didn't see any values for the second input in the controller, so I removed the pin from the Ampseal connector, and there was no change in the bike's operation. I have no idea why a company would do that. I'm not complaining. It saves me some work, and leaves me a place to tap into the input while leaving the main harness intact.

[TheRan]

If my understanding of the second input from your initial post is correct and it serves as a backup in case of a fault with the throttle, perhaps it only functions in case of that fault? For example if you were to remove the first input instead maybe the second would be activated once the controller detects that something is wrong.