wr250f conversion

[j bjork]

I have a 3 speed switch, but havent used it much.
I felt I got a little delay when Im not in high, and in linear throttle it is pretty controllable even in high when I have got used to it.
I have done some rock climbing, but not really tricky ones.
I will have to test more in the coming practices, I got talked in to a competition with some tricky rock climbing soon

The trickiest part: https://www.youtube.com/watch?v=DphyJxZbfyM
Edit, maybe a better view: https://www.youtube.com/watch?v=tIaxtPhjy4Q

 

[dougf]

That race looks like fun although a bit muddy for my liking.

Been riding my bike to work, i tried 224 and linear today but it still feels a bit unresponsive to me, probably because im riding on the road and going faster then 80 most of the time. Ive also set my upper batt current limit to 400A which feels pretty good. There's probably more available from the battery now that i beefed up the copper sheeting but im guessing offroad its just gonna be more wheelspin. I definitely like using it as a road bike. Soooo smooth, quiet and peaceful. A shame i only get about 80kms from a charge in town. I have a new charger on the way which is supposedly only ~2.5kg and will do 4kw. That would get me topped up in about an hour and a half. Hopefully its good.

Doug

 

[fechter]

Wow, how many riders started on that race? Huge crowd.
The wet rocks look brutal.

 

[j bjork]

Sorry for the off topic, it should have been in my thread.
It is maybe 1500 or so starting, different classes with a few up to several hundred in each class.
I think it will be about 5-600 starting at the same time with me

 

[dougf]

Its fine, if you plan on riding an elec bike in comps like that, close enough to topic.

Did about 50kms of single track and fire tracks today. My first proper offroad ride with the fardriver. Pretty stoked. I started on your recommendations of linear and 224. About 20 min in i changed throttle high value from 4.35V to 3.8V and that made it more ridable. Was struggling to get any snap. With those settings i could pivot turn, log hop and control wheel slip on wet mossy rocks. Low speed wheel spin control is 10 times better then the apt was. There is still a tiny bit of rubber band effect, say when pulling a wheelie, but its so minimal that i think its ok. It might not even be a controller issue. Im guessing there is a reasonable amount of rotating energy inside that motor. I might be able to test by doing step responces on the dyno.

I still feel its a bit too much throttle twist, eapecially at faster speeds. I definitely think having the throttle curve mappable against speed is worth a shot. More work for future Doug. Still though, dont really want an IC dirtbike anymore.

I have some 360 footage, if any of it is good ill put it on youtube.



Doug

 

[speedy1984]

Hi ya,

So if you change the throttle end position voltage does it auto change the rpm (Ratios in Speed) settings and will it still hit its max rpm do you know?Im also hoping i can take some throw out the Domino throttle and gain some initial snap in another throttle setting if possible.I found Linear at 224 very easy to work with but always looking for better if the controller is able :thumb:

 

[j bjork]

You have a magura throttle right? I have tried one, and it had a pretty long twist. I have a short twist hall throttle, shorter than a domino.
I agree on the snap, it isn't really there in linear.
It is still powerful enough for wheelspin all the time, so snappier wouldnt be very useful (but fun).

Are you on high? I tried riding on mid today, and it was as I remembered.. A little delay and a little rubberband effect.

Can you control it on slippery rocks in sport?

Yes, I think evaluation on the dyno is necessary :lol:

 

[dougf]

Hi ya,

So if you change the throttle end position voltage does it auto change the rpm (Ratios in Speed) settings and will it still hit its max rpm do you know?Im also hoping i can take some throw out the Domino throttle and gain some initial snap in another throttle setting if possible.I found Linear at 224 very easy to work with but always looking for better if the controller is able :thumb:

Yeah so the way it works is the low Voltage is 0% throttle and the high voltage is 100% throttle. By reducing the High voltage you can make the throttle throw shorter, however, if you twist it too far you will trip the drive with a throttle error.

Linear is good for slow speed, also makes it a lot easier to power slide, but I think for pulling wheelies above 80kph its a lot of wrist movement, especially considering on a IC you would nip the clutch.

You have a magura throttle right? I have tried one, and it had a pretty long twist. I have a short twist hall throttle, shorter than a domino.
I agree on the snap, it isn't really there in linear.
It is still powerful enough for wheelspin all the time, so snappier wouldnt be very useful (but fun).

Are you on high? I tried riding on mid today, and it was as I remembered.. A little delay and a little rubberband effect.

Can you control it on slippery rocks in sport?

Yes, I think evaluation on the dyno is necessary :lol:

Yes a Magura. I wanted someting that took normal grips. It does turn pretty far. I will probably swap it out for a stock tiger 800 electric throttle which are quite good. I do need to check that the larger assembly fits between the bars and the front brake master cylinder. I sort of liked the hall throttle feel that came with the APT but it was a bit, hmmm, cheap is probably the right word.

I agree, not much need for more snap down low, but north of 60kph, yeah, Id like some more.

I did have a switch for Mid which reduced the power down to 50% and max rpm of 1000 but to be honest, didnt need it on the slippery rocks. I could feel the back wheel spinning and stop it before it got out of hand. I didnt try sport, I dislike the surging in sport now that Ive ridden in linear. I will wait until I make a dash with programmable throttle curve.

I will get some dynotime in at some stage. The dyno is currently horizontal against the wall behind piles of stuff as a mezanine goes up.

I thought this was funny when I watched it back, just how Australians talk I suppose.

https://www.youtube.com/watch?v=DX2O8JwctOI&ab_channel=gyrodoug1

I have a bit of footage, I will put up a technical bit in some rocks and logs later.

Doug

 

[speedy1984]

Hi ya,

So if you change the throttle end position voltage does it auto change the rpm (Ratios in Speed) settings and will it still hit its max rpm do you know?Im also hoping i can take some throw out the Domino throttle and gain some initial snap in another throttle setting if possible.I found Linear at 224 very easy to work with but always looking for better if the controller is able :thumb:

Yeah so the way it works is the low Voltage is 0% throttle and the high voltage is 100% throttle. By reducing the High voltage you can make the throttle throw shorter, however, if you twist it too far you will trip the drive with a throttle error.

Linear is good for slow speed, also makes it a lot easier to power slide, but I think for pulling wheelies above 80kph its a lot of wrist movement, especially considering on a IC you would nip the clutch.

Ok gotcha,just not sure thats going to work for me then tbh if it cuts out if twisting past certain point.I also found unless i was in high power mode in linear the throttle feel was pants.Prob ok for teaching my son to ride a bike but thats it.Would love to see this bike from a third person view,help gauge the speed of this beasty.

Cheers

 

[dougf]

Yeah its annoying. For a long term solution a shorter throw assembly is better. Im a pretty conservative rider so its never really a problem. I clipped some more footage here,

https://youtu.be/RMHfQ5nonNM

Next week ill go back with someone faster and they can catch some 3rd perspective. We were just out for a joy ride, not a race. The girl on the KLX is only just learning and im now fat and old.

Doug

 

[dougf]

A bit more riding yestersay. I modified my magura throttle end stop to reduce the throw, no longer trips out :x and feels pretty good now. Still linear and 224. Someone i was riding with took it for a spin. Was a bit worried i wouldnt get my bike back :wink:. He had a 300 exc which was interesting to ride back to back against the electric. I think for sheer low speed power the electric wins. But once moving, damn that 300 is nice. It probably has an edge on power, or how it delivers power. Its also 30kgs lighter. That being said i easily had the highest top speed of about 140kph. If geared like for like it would be close. I also have my current limit set to 500A. He agreed with me that more power would not make it any better. Really happy with this motor/controller combo.

So a primary reduction on these motors is definitely better then direct drive. A 70t rear sprocket would get damaged very easily. I wonder if i can machine a gearbox that bolts to the front of the motor...maybe a project for later. Right now its still more bike then ill ever be able to handle.

Doug

 

[speedy1984]

Hi, does it actually feel as heavy as it is when riding?That was my main concern with my Enduro build.Trading motor size and ah for something I can flick and bounce around my trails on but still crush hills with bursts of 30 odd kw.I have some good fast MTB trails i can also ride and fully believe it will be a rocket ship down them or at least till I bounce off a tree

 

[dougf]

Hi, does it actually feel as heavy as it is when riding?That was my main concern with my Enduro build.Trading motor size and ah for something I can flick and bounce around my trails on but still crush hills with bursts of 30 odd kw.I have some good fast MTB trails i can also ride and fully believe it will be a rocket ship down them or at least till I bounce off a tree

Not really. The weight is noticeable under braking, but the little wr brakes are also pretty garbage. Otherwise no, I dont notice the weight that much. As I mentioned before though, I ride an adv bike that is 250kg without luggage. the fuel slush alone is enough to punt you right into the rut you dont want to be in :lol: . The guy who owned the 300 described it feeling a bit like a DRZ400 so far as weight goes.

Its a hard call with motor size. Probably something between the 180 and the 138 would be nice, although I haven't ridden a bike with a 138. I just think in my case I overdid the battery by a lot. I could half the capacity to get about 50km of range which would be enough for 85% of my rides and drop ~15kg of weight. I also have heavy hardware on my bike like the bash plate and flex bars. Just hard to get both energy density and power density with small packs.

These are for sale locally for reasonably cheap.... well....cheapish...so I'm tempted to go get one for the missus.



They have the 4spd gear box and make about 12kw, however, a 138 could probably be fitted without too much dramas for some more punch. That or a better controller. They are 78v 40Ah using an APT 72400 claiming top speed of 100kph and a range of 100km. That smells a bit like a lie to me. Around 100kg. Worried the quality might be lacking on suspension and hardware. Might at least go have a look at one in person.

Doug

 

[speedy1984]

Oh thats not bad then if its not really noticeable.Ive never ridden anything that heavy on trails tbh lol.I think a 610 Husky i tried was bloody awful and i had to work so hard to track my lines it became not fun.I would be tempted just to build her a little ktm 85 framed 138v3 build for the price of that.Lightweight simple build that she could put her feet down and manage moving it about on the trails.I just dont trust the QC on them types of bikes and they turn into a money pits.Just my two cents though lol :thumb:

 

[dougf]

Oh thats not bad then if its not really noticeable.Ive never ridden anything that heavy on trails tbh lol.I think a 610 Husky i tried was bloody awful and i had to work so hard to track my lines it became not fun.I would be tempted just to build her a little ktm 85 framed 138v3 build for the price of that.Lightweight simple build that she could put her feet down and manage moving it about on the trails.I just dont trust the QC on them types of bikes and they turn into a money pits.Just my two cents though lol :thumb:

Half of how heavy a bike feels is to do with how you ride it. At ~140kg this wr is a heavy bike and as such cannot be man handled around as easily as something lighter. I also dont tend to do much hard enduro style of riding. Will ocassionally hop logs or climb muddy hills but its an exception, not a norm.

My missus isnt short at over 6ft. She needs a full sized bike and usually tosses around a 310gs or her klx. I think a second Ebike would be better then the klx. I hear you on the converting a quality bike instead of getting something like the chinese e bike. I am still a bit curious about them. If he has a demo unit i can look at i will.

Doug

 

[dougf]

A small update. Got some time in the last week and started writing some code for my custom dash. Lots of typing. This is my first time programming STM32's. Seemed like a cool 2 for 1 to use them on this project but it's seriously kicking my a$$. Getting there. I have no idea what I want it to show for normal riding. I definitely want to have access to all the parameters though.





Input on what to show on the screen besides battery SOC are welcome. Probably Low, MID or HIGH. Il have it show reverse when I put it into reverse. Probably some messages about the state of the contactor and some safety stuff around if the bike is "on" or electrically locked out....ima need a new keyboard after this, especially the backspace key :lol: .

Also, I just assumed the chinese were correct and these drives used RS485 between laptop and drive but nope, they are just UART, not even proper RS232 .

Probably another week of bashing my head against the table here until I have a V-1 of the firmware. I will need to spin a pcb and machine an enclosure. I picked this screen for daylight reading and because it will fit nicely between the cross braces of my handlebars.

Doug

 

[j bjork]

I dont know what time it is down under now.
But here it is sunday afternoon, and I am patiently waiting for dyno updates :wink:

 

[TysonScott]

I dont know what time it is down under now.
But here it is sunday afternoon, and I am patiently waiting for dyno updates :wink:

nice! im excited to see how the motor does. how many battery amps is going to it?

 

[dougf]

Ha, sorry guys, I didnt get a chance. Im part way into building a new trailer to carry bikes after giving my old one away. I also think it would be smart to integrate the controller comms directly into the dyno software. That way the dyno will automatically plot phase amps, batt amps and voltage on the same chart. The update rate is a bit slow from the controller so perhaps external sensors are a better choice for that. Would also be great to have the dyno control the throttle, or at least sample the throttle position to some degree of accuracy. That would be nice to measure rubber band effect and responce. Thats a lot of work for me though so maybe initially ill just do some pulls to get the general idea, then later all that stuff.

Doug

 

[j bjork]

It is a long time since last update now, what is happening with the display and dyno plans ?

 

[dougf]

It is a long time since last update now, what is happening with the display and dyno plans ?

Nah, really havent done anymore lately. I finished the new trailer but ive been busy out flying. Got to a point where i need to sit and type up a small book's work of code and needed a break. Pretty happy it's all going to work so Im going to draw up a PCB in the next week or 2 put it all together. I dont have to program the whole thing now, I can add functionality as I get time to write more code.

Otherwise the bike is going good. Got all new plastics and I need to make up some new covers for the controller. Its been really reliable and i dont miss the engine noise. I wish I could use it for longer adv rides. I could probably make an extra battery pack that bolts on under the frame and replaces the skid plate. Would loose ground clearance but for light adv riding it would be fine. Would keep the weight low...that or triumph tiger conversion .

Doug

 

[dougf]

Bit of an update. Spun a V1 pcb up for my dash so I could move it onto the bike for testing. This is not the final form as I plan on machining an aluminium enclosure for it with waterproofing and whatnot but will do for dev. Im using a stock triumph left hand switch assembly which has a couple of extra buttons. They let me set the gear on the fly, select reverse by holding down and when Im finished programming it all in, I can adjust drive parameters. Some are already implemented like throttle mode, brake logic, etc.

Using it, not sure how many parameters I am going to put into the dash. Doesnt hurt to have them in there but at a certain point your better off digging the phone out and using that. More likely to make up presets that I can jump to. Road, offroad, traction control, etc. This PCB has none of the fancy throttle stuff I talked about earlier in the thread. Just bare bones.

Still, some progress, will be riding the bike to work for the next few days while I debug stuff. The battery calibration in the controller is pretty far out so I suppose ill need to run the bike flat and calibrate it.

A new update on the JK bms Im using. Turned it off the other day and BANG, blew up half the fets again. I cannot recommend these BMS units, too unreliable. For now I will just leave it turned on and plugged into my charger to keep it topped up but i will need something different in the future.

Doug

 

[j bjork]

Nice with some progress :thumb:

What was it you had found with the motortemp, didnt you get a reading at all?
I have a reading that is a little high at ambient if I remember correct, but I have never tested what happens when the motor gets warmer..

Maybe motortempcontrol is something for your display?

 

[larsb]

A new update on the JK bms Im using. Turned it off the other day and BANG, blew up half the fets again. I cannot recommend these BMS units, too unreliable. For now I will just leave it turned on and plugged into my charger to keep it topped up but i will need something different in the future.

Doug

Which jk bms is it that you’re using? I’ve looked at one with supposedly has overflow balancing which seems interesting

 

[dougf]

Nice with some progress :thumb:

What was it you had found with the motortemp, didnt you get a reading at all?
I have a reading that is a little high at ambient if I remember correct, but I have never tested what happens when the motor gets warmer..

Maybe motortempcontrol is something for your display?

The controller doesnt seem to get a reading. I thought Autotune was supposed to pick it up, but it didnt, just put it to "none". When I manually set a temp sensor I get a fault. The old APT controller had the temp sensor set to a 1K PTC. Seems a bit odd, usually NTC's are used. I probably have a wiring issue and need to put one side of my temp sensor to +5v instead of ground. Just havent really looked into it because as I have mentioned, Motor only gets warm and my battery will go flat before it overheats.

But yes, I can display the temperatures on the dash and Ive already decoded where the controller mosfet temp is in the data stream. I still need to work out battery and phase current. I found what looks a bit like watts but am unsure because it looks low while Im riding along. Maybe the controller shows motor Watts instead of battery watts??. Sort of need to get the bike onto the dyno to work those ones out I think.

Which jk bms is it that you’re using? I’ve looked at one with supposedly has overflow balancing which seems interesting

A JK-B2A24S with the canbus option. If they didnt intermittantly blow up when being powered off they would be great. I believe it semi Browns out during power down and because of the way it measures and balances it can essentially connect sells together shorting out thru the fets. They have surface mount fuses to protect the fets but they dont always save the fets. Pretty easy to repair but not the point. Because my battery pretty much never needs balancing I tend to leave it turned off and turn it on every second or third charge to check the balance. For now Ive just left it powered up but I will need to top the battery off as it goes flat.


Done some testing last week while riding to work. My bike has a surging problem when at a constant speed. Smooth on acceleration but when trying to hold a speed it will pulse, a bit like a 2 stroke on the edge of resonance. I thought it was my Majura throttle as it started doing it worse when I fitted it but it doesnt seem to be the case, at least not the whole story. What I can see now that I have the info in front of me while riding is that the throttle ADC reading is pretty constant while the motor % output is jumping a lot, like 10-15%, under constant speed conditions. My guess is its probably a PID issue. There are some speed PID parameters and last ride home I halved them both and it was a bit better but not fixed. Il try turning them all the way off and see if it makes any difference. Otherwise its probably a current or torque loop oscilation. It is almost inpossible to feel when riding offroad but on road very noticable.

Other random things I have worked out. The battery SOC feature of the Fardriver is actually pretty cool. I didnt understand what It was doing initially. Basically the low batt coeff and the full batt coeff let the controller dead reckon the battery SOC on boot, then it can actually measure capacity used from the current draw and based on the battery capacity field will know how much battery you have used. It works great, however, if your using a precharge resistor during boot it will not have an accurate voltage to dead reckon from and it will be out. Given Im probably the only person on the planet using that feature its probably useless information but I think it's cool. As a side note it would be very easy to take a small esp32 with integrated LCD and have it read SOC for those wanting a simple solution on there bikes. Could easily be done in arduino.

Additionally, if you buy the Encoder variant of the 961800 it has some different wiring and inputs. One of these inputs is called "Forward". It is indeed not a forward input but the input for an alarm system :lol:.

Still need to test variable regen. The PCB I made doesnt have an ADC input on it so for testing purposes I will just have the e brake step between two different brake settings while braking. If it pulses then :thumb: .

Doug