Can I replace the cheap controllers (and display?) on my 2x1000w SMLRO XDC-600?

[eTouringOldie]

Reading m@robertson's article

I Hate Ebike Torque-sensing (maybe you should too)

from Tales on Two Wheels, he describes poor cadence sensing PA systems, and mine clearly falls into that bucket. It's on/off when I pedal, so I either get no assist, or full assist up to the speed limit for that PA level.

I'd really like to have PA which pays attention to my cadence, raising or lowering motor output as my cadence changes within the limitations imposed by my selected PA level.

But I have (literally) no clue how to figure out what I need. And the key point is that whatever I replace the existing kit with has to control both motors. Folks have suggested 'Cycle Assist', and that might be the best answer. While that seems like added complexity I very well may end up there. But I'd at least like to explore whether upgrading the controllers and display is feasible and beneficial.

Can anybody out there help me get started on this?

Thanks!

 

[ElHegpah]

Can you replace your existing controllers? Almost certainly.

Will it be simple and easy? Almost certainly not.

Will the new pedal assist be BETTER than what you have now? Total crapshoot. It's an opinion.

Can you do it with just one controller? High odds for HELL NO.

Have you considered just using a throttle to control the power output of the motor? Then pedal to that output? With a better throttle, this is often more feasible. Magura is one recommended brand.

What you will find is a dozen different systems for handling pedal assist, and a hundred different opinions on them. With the throttle, YOU control the motor, rather than the system controlling YOU. You are not bound by someone else's system design.

 

[eTouringOldie]

Thanks for the response!

Honestly, if I could be sure of better I'd be willing to deal with complex and difficult

With the current (stock) setup, the throttle is on/off, just like PA. My assumption has been that the controller is where the problem lies.

Are you saying that a different/better throttle would override the Cadence sensing input to the controllers (and thus to the motors)? So if I set my PA to 2 (max speed is 20kph) but only crank half throttle, I'll get to 10kph, but no further, regardless of what my cadence is?

I'll have to adjust my thinking. To me, it really feels like the controller is in charge of the 'on/off' behavior. But I guess you're saying that my throttle probably sends either a low or high voltage signal to the controller, which interprets the signal as on or off and sends the proper voltage for the current PA setting to the motors. And I guess that means the cadence sensor does the same (high/low signal ==> on/off).

I guess I was hoping that someone else had designed a system which behaves the way m@robertson suggested. By that I mean variable cadence sensing Pedal Assist.

Ugh!

 

[Hoggdoc]

Reading m@robertson's article

I Hate Ebike Torque-sensing (maybe you should too)

from Tales on Two Wheels, he describes poor cadence sensing PA systems, and mine clearly falls into that bucket. It's on/off when I pedal, so I either get no assist, or full assist up to the speed limit for that PA level.

I'd really like to have PA which pays attention to my cadence, raising or lowering motor output as my cadence changes within the limitations imposed by my selected PA level.

But I have (literally) no clue how to figure out what I need. And the key point is that whatever I replace the existing kit with has to control both motors. Folks have suggested 'Cycle Assist', and that might be the best answer. While that seems like added complexity I very well may end up there. But I'd at least like to explore whether upgrading the controllers and display is feasible and beneficial.

Can anybody out there help me get started on this?

Thanks!

I solved that issue on my 2020 Himiway All Terrain by adjusting the percentage of power available at each PA level. Mine starts at 20% for PA 1 and tops at 99% for PA level 9.

 

[eTouringOldie]

I solved that issue on my 2020 Himiway All Terrain by adjusting the percentage of power available at each PA level. Mine starts at 20% for PA 1 and tops at 99% for PA level 9.

Only 5 PA levels on my bike. Another reason I'd like to upgrade.

But on your bike, you still end up with full power for the chosen PA level once you start pedaling, right?

 

[ElHegpah]

Typically, throttle is totally independent of PA system. Some PA have a wide range of adjustability, some don't.

On your throttle, there should be a narrow range of adjustability, on mine about one-quarter of the total travel, where it has a speed range. Try this with min and max PA selected, may be a difference.

Was the device you were recommended a Cycle Analyst? Good kit, not sure if will solve your issue.

Dual motor setup complicates life.

Do a detailed exam on the display for menu options, check the manual. Sometimes there are hidden settings.

 

[eTouringOldie]

Typically, throttle is totally independent of PA system. Some PA have a wide range of adjustability, some don't.

On your throttle, there should be a narrow range of adjustability, on mine about one-quarter of the total travel, where it has a speed range. Try this with min and max PA selected, may be a difference.

Was the device you were recommended a Cycle Analyst? Good kit, not sure if will solve your issue.

Dual motor setup complicates life.

Do a detailed exam on the display for menu options, check the manual. Sometimes there are hidden settings.

Throttle seems to be on/off at any PA setting, but I'll test out the 'maybe there is a small range which varies input to the motors' theory.

When you say '...totally independent of PA system...' I think you mean independent of input from the sensor. That's definitely the case -- when I use the throttle, pedaling hard, easy, or not at all doesn't change motor output as far as I can tell. But it's not independent from the PA system in the sense that the throttle 'obeys' the speed limits designated for each PA level (basically +10kph per level).

Yes, Cycle Analyst. Agree that dual motors makes things more complicated, but it seems to be set up as a 'master/slave' pairing. That is, there's a bigger 'main' controller which all the cables (throttle, brakes, PA, display, lights, etc) go to. Then there's a smaller controller which only gets a few cables -- haven't painstakingly traced all the wiring yet.

I checked the manual to see if it contained any info on controller settings -- unfortunately it provides no information on any of that. It does tell me I should wear a helmet though, so not completely useless

 

[ElHegpah]

Sounds like what you have is 5 "speed" settings, with no variation for cadence.

Try max PA setting and very small increments on throttle to see if you get any variation there. Mine is dead for about half the travel, a bit more, then a narrow range of variation. Better throttles have a wider range, but some compatibility issues.

Changing dual controllers, with dual motors, and then using PA for both, is going to be an adventure. Please report back on results for future users.

Contact Justin at Grin, makers of the CA, and see if it will work. It does combine throttle input for two motors, I think, PA I am not so sure.

 

[fabbrisd]

From what I understand - NO you do not need to Change Controllers - YES you can improve the Riding Experience you have now:

1. You have Right-Hand Twist Throttle - correct ?
If Yes - to give you better/easier throttle control - order this $10 "Cramp Buster" from Amazon - clip it over the throttle grip - and then use your|
palm to control/fine-tune yourt throttle - a MUST HAVE FOR ANY THROTTLE CONTROLED EBIKE
CLICK HERE CRAMP BUSTER THROTTLE CLIP ON

2. SAVE this YouTube Video which goes thru Each-Of-The-17-User-Settable-Display-Settings for your eBike:
CLICK HERE M5 LDC SMLRO DISPLAY

 

[fabbrisd]

1. Improving Your Riding Experience Yes - Grin is a good resource - but frankly you are nowhere near needing that level of eBike Control Sophistication - save that YouTube Video - if that is your bike's display - Go thru each of 17 Advanced Settings - with emphasis on each setting after Setting#9 - abd especially Settings 12-15.
One advantage of eBikes - is the range of adjustment each offers - YES you have 5 PAS levels - SURE you would "prefer" 9 - but frankly whether its 5 or 9 PAS levels - that's not the issue - you want to Improve Your Riding Experience !
You and the settings - you both need to get personal with each other.

2. Improve Your Ownership Experience - please understand that you WILL GET A FLAT TIRE - coule be your next ride - or the next ride a bit later.
(a) Order in 2 spare tire tubes now to have at hand to replace that tube when you do get a flat - patching tubes is long gone.
CLICK HERE AMAZON $18.99 FOR 2 26X4 BUTYL RUBBER TIRE TUBES
(b) Order in and install 3XL (Tan) Mr Tuffy tire liners - pricey but Best Tire Liner Protection: CLICK HERE AMAZON $63 PAIR 3XL TAN MR TUFFY
(c) Order in and install 16 0z each tire FlatOut Sportsman Tire Sealant : CLICK HERE AMAZON $20 32 OZ BOTTLE FALTOUT SPORTSMAN
(d) Your China 4" Chunk tires are "OK" - but if you are riding street or paths consider changing those chunky, heavy tires for smoother & better ride:
CLICK HERE - $100 PAIR - 26x3.5 SUNLITE BAJA BLACKWALL STREET TIRES - LES 10% SIGN UP FOR MAILING LIST BEFORE ORDERING

 

[eTouringOldie]

@ u/ElHegpah & u/fabbrisd

Thank you both very much for your assistance!

Yes, it is a right-hand twist throttle, and it turns out you are both right— I was able to throttle @ 11kph on PA-5, while full throttle would be 50kph. And it does obey the throttle even if I pedal. In PA-1, I could only drop speed down to about 8kph (from 10), but that’s much less important to me than finer control at higher assist levels.

Also, thanks for the link to that video — I was really frustrated not to have that information.

I do wonder if a better (more magnets) cadence sensor will make any difference.

@ u/fabbrisd re: your last msg, yep, I’ve been vacillating between your b) & c) choices. I don’t see changing tubes ‘on the trail’ as Plan A, although I do carry a spare, and will carry 2 when I’m on an ‘expedition’. I’ve seen a fair amount of disagreement over which is the better solution between liners and sealant, do you have an opinion? I’d prefer reliability over less weight, and, within reason, cost is a lesser consideration.

I suspect my current use (mostly logging roads) is both more and less ‘dangerous’ for tires than road cycling — no chunks of metal or boards with nails that fell off a pickup to hit, but lots of sharp rocks (chip to provide traction for trucks in rain). So I’m happy w/ my tires for now. Later, if I’m riding more distance on roads, who knows?

I really appreciate you providing the settings video link. I look forward to seeing how well I can modify its behavior more to my liking and adapt my style to its character.

About the Cramp Buster, looks very practical. I do wonder if there are grip issues in technical terrain? Also inadvertent throttling? I suppose they’re easily removed and tucked away until needed again.

 

[fabbrisd]

1. Flat Prevention for me is (a) adding a reputable TPU Liner (like Mr Tuffy). Note "almost all" lower cost TPU Liners get horrible reviews (b) after adding Liners - add FlatOut Sportsman Formula - you mention kph - do you haver that in your area ? Fat Tire requires 16 oz ea tire.

2. Logging Road Expedition Tires - when you are looking for your next tire set - under Sunlite Brand there are UtiliT Starman and UtiliT Big Fatty 26x4's - about $50 each - both tread patterns are (a) Wire Bead and (b) 30 TPI casing

With your Expedition Direction - its possible your next major investment will be to consider a 2nd battery - linked with a "eBike "eBike Battery Combiner"also called "eBike Battery Blender" which gives youabout 15%-20% total range over swapping-n-out as singles.

 

[ElHegpah]

Battery blenders are evil and dangerous and should be avoided at all costs.

They will mask an unsafe condition inside the battery, as they will prevent accurate monitoring of individual parallel groups.

 

[m@Robertson]

CLICK HERE M5 LDC SMLRO DISPLAY

Looks like Option 11 defines pedal assist sensitivity which only decides how much pedaling it takes to initiate pedal assist. Option 12 decides PAS level increment, in 5 steps. This is the only place where you're going to get a change in PAS power level behavior to try and mitigate - but not solve - the on/off behavior. That ain't much.

Reading m@robertson's article

I Hate Ebike Torque-sensing (maybe you should too)

from Tales on Two Wheels, he describes poor cadence sensing PA systems, and mine clearly falls into that bucket. It's on/off when I pedal, so I either get no assist, or full assist up to the speed limit for that PA level.

I'd really like to have PA which pays attention to my cadence, raising or lowering motor output as my cadence changes within the limitations imposed by my selected PA level.

I'm not sure when you read that article, but on Wednesday the 8th I went back and revised it to try and do a better job (than I did in 2019 when it was first written) of describing exactly what it is you are talking about, and went into specifics of how KT controllers have what they goofily call 'imitation torque control' as an algorithm for their cadence-based pedal assist. That is WAY different from the on/off switch you get on most Far-East DTC/web site ebikes. If you didn't see the whole new section dedicated to this, sorry about that.

Having done a bunch of twin hub 2wd ebikes, I can tell you exactly what you need to do to make your change, the most economically. Its an ugly list. Essentially you need to tear out almost everything and start over.

That single controller covering both motors is not readily replaceable with anything of any level of quality. In fact, single-controller systems - with the exception of something controlled by a Cycle Analyst and a Grin Tech controller - are all junk. I consider them a V1.0 solution at best if I'm trying to be nice. Something cobbled together to sell to people who don't know what they otherwise could have in terms of performance and features, frankly. Here's what I would do, to do the job properly. And no I'm not sure your bike is worth all this effort. I'm just going thru a complete how-to for the sake of putting it out there.

1. Pull out the controllers, throttles, displays, PAS sensors and batteries (I told you this was ugly). We'll try and re-use what we can but it might be 'nothing'
2. I am assuming you have the smaller Bafang/HIGO motor plug on your motors. The 9-pin one. If so, I'd go buy two KT 25a controllers, one for each motor. If you have the big plug it means you truly have a higher-power-rated motor (I doubt that is true despite what the advertising says) in which case you'd have to go for the 35a KT controller. This is the link to where I buy my 25a KT controllers. I get the 35a units from the same site.
3. House the front controller in a handlebar bag. I use a Condor deployment bag and use a grommeter and brass 3/4" grommets to give me durable holes (wide enough for an XT90) in the bag to run cables directly inside. Water ingress is not an issue.
4. You will need a dual-PAS sensor solution. Doing without dual-PAS on a 2wd bike is an awful solution. Dual PAS is an awesome feature. It is not worth trying to tell yourself that lacking it is acceptable. Been there and done that on builds where I had to wait for parts and then, once installed I had the direct comparison to make. This is where I had my splitter cables made to order. He still offers that service, but nowadays he sells pre-made splitters. So you would install your PAS sensor as normal and use one of these pre-made splitters to send your PAS signal to both controllers. To re-use your existing PAS sensor you may need to make a custom cable with the right genders on each side, which is what I did back in I think 2017. You decide whether its cheaper to just buy another PAS sensor to match the female plug on the controller or do an adapter somehow.
5. Ideally, you will split your brake cutoff signals to the two controllers just like you did your PAS signal. Each brake lever will need a splitter, and depending on your situation you may also need a yellow-to-red HIGO adapter (sold by the same site, as well as quite a few others). I use Magura brakes which also use the red HIGO plugs so I didn't need adapters here, but I did have splitter cables made. You will have to do some google-fu but you can find cheap red-to-yellow HIGO adapter cables.
6. See if you can plug your throttles into the controller. I doubt you will and this will mean you have to buy the $30 throttles from the same source above. Thats a minus of course, but the alternative is to go out to AliExpress or Ebay and find a controller from a seller you trust with Bafang-default cabling (not the worst idea in the world, but its not a plug/play solution).
7. You're not done yet. KT controllers require KT displays to be able to access their settings interface. I used to use the KT-LCD3 or the color KT-LCD8H. But more recently I have been using the KT-LCD4 which is both cheap and minimal in size. Its a Bafang SW102/EggRider display casing, with an always-visible backlit LCD screen and full KT feature access. It even displays real-time battery voltage. Its also relatively cheap. Here is a link to a seller I am currently waiting on a pair of them from to refit my Great Pumpkin. Two of them sold to me for $47. So figure if you buy one its roughly a $25 display. These tiny displays are highly visible to the eye and almost unnoticeable to passersby.
8. One more thing: Its unlikely you have the right cable lengths for everything. I buy my HIGO mini cable extensions from Amazon.
9. To re-use your battery, you have to dumb down the controllers. KT controllers have a setting (C3) that lets you back a 25a peak controller down in steps all the way down to 12.5. So your battery could have a 30a BMS and still be fine with two motors since they would only peak out to 25a total. In an ideal world you buy a new battery with a 60as BMS so you can handle the full 25a per motor (50a total) peak. Ideally you figure out what your existing controller outputs, and your BMS can handle. Leave yourself some fudge - don't take your controller capacity up to the line of the BMS. I like to leave 10a, and I have made the mistake of matching peak controller to peak BMS and done the walk of shame home when I discovered why you don't do that (you'll have to plug the battery into a charger to re-enable it if the BMS pops).

An AWD bike is twice the work and you get a single bike at the end of the project. But the benefits of AWD, plus the granular control of dual throttles, makes the dual-controller solution worthwhile.

 

[m@Robertson]

Battery blenders are evil and dangerous and should be avoided at all costs.

There are good and bad ones. Figuring out which one you are buying is best left to someone who doesn't need to ask which is which. Plus a single battery is always going to be a better solution for a variety of reasons. The drawback is a battery with an XL-capacity BMS and XXL cell count is expensive and always a custom order.

They will mask an unsafe condition inside the battery, as they will prevent accurate monitoring of individual parallel groups.

Yeah but who actually does that? Certainly no ordinary consumer as you need special equipment to do it.

Personally when I have parallel'd batteries I have always done it directly. Used them for years. Won't describe how because if you have to ask you shouldn't do it. Even though you can do the parallel pack thing reasonably safely, its not as safe as can be, but a big single pack is.

 

[eTouringOldie]

@ u/fabbrisd
I already have a second battery -- 2 x 22Ah @ 48V. Not sure the Battery Blender idea makes sense for me -- there's no obvious place to mount the second battery. Right now it's being carried in a luggage bag on my rear rack to be swapped in when needed. Also, when I'm expeditioning, I intend to have the second battery solar charging in my trailer. In experiments I've been able to charge at over 2 amps off 2 100W solar panels via a boost mode charger. Of course that figure drops on either side of 'high sun', if it's cloudy, or when I'm riding in shade. So not enough to make up for what I'm consuming, but probably extends my range by 20 - 30%

Ordered a CrampBuster -- my wrist is already thanking me!

Turns out there are a number of videos out there discussing M5 P-settings. Found the 'walk mode' and 'cruise mode' triggers in another one. Thanks again for the pointer. Actually, the best info/suggestion was 'record your settings before you change them'

I think you're saying it would be best to combine the 'liner' and 'sealant' flat solutions -- makes sense.

@ m@Robertson
You are correct. I read your article prior to the edit/rewrite. Along with your great post above, I guess I have a 'light reading' assignment for the weekend.

Before I take on what looks to be pretty challenging, I want to see how much improvement I get from changing the P-settings and using variable throttle control to tune my riding experience, although you seem skeptical that I'll be satisfied.

Also, at first glance, the 'ugly' part makes me wonder if the 'Cycle Analyst' approach might be easier while providing similar benefits. Seems like 'all-in' the investments (CA vs KT controllers and display) are in the same ballpark, and substantial enough that I don't want to try both.

In any case, thank you for the assistance!

 

[m@Robertson]

Yeah this is a lot of work. And since your battery (batteries) is very likely to have a low-power BMS, it may be the ONLY benefit you gain is going to be from better pedal assist behavior. Unless you find a way to make use of that second battery, which is definitely do-able. Dual controllers enable completely independent systems, so one battery per axle is entirely possible. I've done that. Its another one of those v1.000 kind of solutions but it will eliminate the issue of popping the BMS if it turns out you simply have a big battery with a 30a BMS and a low power controller.

The Grin Tech solution will be the most robust, but you will have to do a lot of work under the hood to develop everything yourself. The controller is largely a clean slate. You definitely want to talk to Grin directly to see if what you want to do is something they would recommend.

While we are talking about adding power, your front fork is a suspension fork with no torque arms. The way these commercial low-cost manufacturers get away with that is by only providing low power to the front motor. They don't tell you that but thats the only way to do it and stay safe. Consequences of hi power + suspension fork are often catastrophic failure. Dropouts snap clean off. I never built a 2wd bike with front suspension for this reason (Kinekt suspension stem and fat tires is best substitute). I've seen suspension forks on bikes I was riding flex forward and pull themselves apart a little even on low power. Unless you go to a solid front fork do not do anything but low power on that front fork.

Are the motors Bafang or some other clone? If Bafang G060's then what I described will for sure work. If not, buy one controller only and test.

 

[Hoggdoc]

Only 5 PA levels on my bike. Another reason I'd like to upgrade.

But on your bike, you still end up with full power for the chosen PA level once you start pedaling, right?

Yes but I only do that on PA level 9. I start at 20% level 1 and increase 20% for each level up to level 9. Has worked well for me. I have also toned down the startup surge so it doesn't launch you when the power kicks in.

 

[ElHegpah]

"Yeah but who actually does that? Certainly no ordinary consumer as you need special equipment to do it."

No, EVERYONE with a BMS in their battery does this.

 

[eTouringOldie]

Can't live without a suspension fork. I have ridden a rigid analog MTB on the logging roads, and downhill was just brutal, especially on my elbows. I think it's the chip -- constant rattling transmitted straight from the wheel to my arms.

Very interesting about front wheel power limitations. Where would they control that? My front wheel controller is 25amp so theoretically could deliver the full 1000W the motor wants. But I suppose they have de-tuned it.

The motors don't have much identifying information -- certainly no brand info -- just some gobbledygook numbers which don't return results when googled.

Honestly, this is all new to me. I suspect my next effort will be to build a mid-drive w/ a BBSHD which I can program down to street legal. But that's a 'ground up' project, since I'll want to beef up the drive train from chainwheel to rim. The work it will have to do hauling 450ish lbs (rider, bike, trailer, solar, spare battery, gear) up into the Cascades and eventually the Rockies will require a lot of 'chain-eating' torque. I've considered going with a belt drive, but the cost of a quality IGH seems prohibitive, and I suspect a beefed up chain drive will be just as failure resistant.

So someday soon I'll have to quit spending money to 'fix' the inadequacies of the bike I have. I'll end up calling the whole process a learning experience, and somebody will get a good deal on a lightly used dual hub-drive bike. But ... It is Not This Day