DH dual motor = LR mid drive + Grin all-axle front hub

[John Bozi]

Cool John! Sounds like your getting the chain skipping figured out. So how is it handle the hills? How is speed?

Went for my ride and the chain only skipped once.

That sounds great because the last ride I couldn't get up moderate inclines (in my books.

So I took the kit for the first time to true steep sections.

I am struggling to find how to climb them with this kit. If I leave the power open to 5kw I find climbing super steep complex rough terrain uncontrollable.

So I kept trialling setting on the CA to limit power but nothing seemed doable.

The trottle is too twitchy. When you are on an incline maybe 20+, stuff where you are holding the brake lever and trying to not slide backward and then try to bring on the power, I found I couldn't manage the power level.

Take up a step back. I can do all this terrain with my tiny slow bafang motor geared to super slow. It has the perfect amount of torque in its one gear to climb everything that traction will allow. It does it at wot
so there is no thought at your hand trying to manage the power. At 10kmh there is the perfect speed to climb the point before traction loss and the terrain is always rocks here and there which must be manouvered through
so that you don't come to a stand still.

Yes the bafang would overheat if doing this continuously for over 5 minutes but it got me through to the parts where the hub could kick in again.

With the LR you have to bring on the possible 5kw slowly so you don't flip or go into a spin on what is already a hard to hop on bicycle angle.

I had a skip on the chain and gave up after a few attempts to do what my bafang could manage. I will probably have to go to a larger rear sprocket some how to get even more tooth engagement. That will then mean an even higher pitched scream to get to the same speeds. I don't see the need for a smaller chainring at the BB now...

So the CA is kind of useless in trying to manage power in the tight band of power because it cuts in and out the power limiting to abruptly.

I tried to limit power so I couldn't flip the bike because it was already on an angle but when you are depending on its management with your balance leaning over the handle bars you can't have power cuts and then the power cutting in
because you just can't keep your momentum. After trying many settings I felt no setting on the CA were the best as usual. That's why I rode for so long with the blue
throttle wire pulled out of the ca plug. The fluid movement of the hand is better than the jigging in out of the ca a million times.

Hence I come back to my same point of running one motor in one gearing.

I am sad to say for now that riding the steepest 10% of terrain that I could with my dual motor looks to be an almost impossibility with the LR kit. The big block kit is better at the moderate steep, but not the extreme steep.

Lets talk about heat. The motor is not a point worth mentioning because the controller is far hotter all the time.

Lets talk about sound. The primary chain is ridiculously loud. It makes me extremely worried where I ride about upsetting people.

Let's talk about the the steel and chains. On the kit the chains loosened up on the ride and became slack and more noisy. There is no doubt that only a couple of AHs into a ride that I need to carry tools to retighten this when pushing over 2kw. So really there is no point to the big block with the drivetrain system I have now.
If I can't harness more than 2.5kw then the small block is lighter and just as capable.

I am still glad I got the big block because if in the future I get time to custom up the drive train things might get better. For now the big block can take much more power than I can actually get the rest of the bike to use.

 

[broke]

Nice wright up

 

[drew12345]

What about 3 speed switch?

 

[John Bozi]

What about 3 speed switch?

From my current understanding is it limits voltage going through the controller which means it would use more amps and heat up what I see as the weakness to my set up right now = The controller is way hotter than the motor.

Correct me if I am wrong please.

EDIT

I just did a ride to the shops first time so rode it similar to a hub motor on easy terrain, was fun as hell but on an actual road I would prefer a hub motor on the park a bit rougher this mid drive was nicer with the weight centered. But any advantage is totally overwhelmed by a chain primary screaming. I used to hub past people that would never turn around. I only had people facing my direction already be amazed of a silent cyclist moving faster than they were accustomed to. Now I have everybody in 50 metres turn their heads and watch me scream past.

 

[bunya]

Hi John, I have a similar problem with my controller. These basic greentime controllers are simply speed controllers rather than torque controllers so when we ask for throttle they will give massive amounts of torque until the throttle speed is reached. Torque controllers are more suitable on the really steep terrain as they provide a direct relationship between throttle and torque, and can apply torque more controllably.

 

[flat tire]

But any advantage is totally overwhelmed by a chain primary screaming. I used to hub past people that would never turn around. I only had people facing my direction already be amazed of a silent cyclist moving faster than they were accustomed to. Now I have everybody in 50 metres turn their heads and watch me scream past.

I hadn't considered this before whatsoever. Interesting.

 

[John Bozi]

Can you elaborate or give an example of an actual torque controller? Is that like those expensive adaptos...?

What a freak out, I pushed the aligator clip in all the way inside the housing presuming it was making good contact down the length of the male connector, but the resistance material to help stop arching pushed an on it so that it was only contacting the tip which was resisting but heating up and started smoking. I instantly hit the charger power off, and pulled the points apart. I wasn't sure at the time 100% what the cause was thinking the lipos were going to blow so although I wanted to run get water on some material to cool down the wiring to the batteries to lessen heat damage they may experience I didn't want to leave the area until I knew what was happening....

I am pretty sure the batteries would have experienced some of that heat so are most probably slightly damaged although they charged up with the other 4 identically so hopefully they are alright...

Carefull guys!!!!!!!!!!!!!!!!!!!!!! If I left the charging area I would have no bike and possibly no house or family...

[youtube]vJM4dnWc8g8[/youtube]

 

[drew12345]

That's scary! I'm very glad you caught in time. I have same connectors so thanks for sharing. Yeah, will be great when you get your bulk charger. Doing it this way is more prone to errors. You should get a bms to make things even easier and safer.

 

[nutnspecial]

Bike's looking really good. Looks hella fun.
Kelly controllers have the option for torque throttle I think, or CA can do that.
The three speed switch on a speed controller simply resets the max speed attainable thru the throttle, so same physical grip twist range, same watts available, but motor rpms can be limitted to whatever you want.
If top is 40mph, you could set to 50%, still get all the same watts, but have 20mph on full grip twist range. Much better modulation for slow speed while keeping power the same. Works excellent imo, just get the thing placed really nice and close to a thumb and it becomes like second nature to 'gear down' for more control in technical stuff. Poor/simple man's ca or adappto imo, but I like it. Cheap, simple, effective, and I feel no need for a torque throttle with a lightish highish power ride no matter where I'm riding.

Did you mention what high speed you're getting on 20s? Close to 30 or 40mph?
Did you weigh the bike yet? I'd guess it must be 60-70 lbs? So that's gotta be alot lighter than the previous, should be really fun playing in the mountains!
Btw I'd love to see a crazy-style joyride/ trailblaze with a bar or chest mount cam hehe

 

[John Bozi]

Finally got everything charged up, and went for another attempt with new settings to keep me to 3kw.

On the part which gets real steep and running it relatively slow to be able to negotiate the rocks the chain ring couldn't handle the power and warped.

Note on this chain-ring, I was always worried about its strength before ever riding it because with finger pressure you could easily squeeze it in towards
the 219 chain-ring with your index and thumb. The teeth are quite up away from where the ring fastens.

There are three possible reasons for this incident.

1. As I have mentioned it easily bends in and out.
2. The torque brace is only a mm away from it.
3. You could try to blame it on not having enough chain for full compression of the rear shock.

However, 3 is not valid because I didn't do a jump (and I have done them before with this chain length and there were no issues when much more compression happened)

I believe the power bent the weak stamped metal chain ring which then hit the torque brace which anything kept the chainring from bending inwards even more.
The 219 and bicycle chain squashed up together and the chain then wrapped and derailed and got locked in against a nut, which then jammed it pulling the rear tension-er forward.

I believe a 32t chaining would have been much stronger because the outer circumference is very close to the bolt on points. So almost no chance of the whole outer part to warp away under load.

The heat does help to turn the nuts and bolts but they re-seize when even cooled a little so this painstaking and still very hard to get off.

Note I made this video, in takes, there is one where I swear looking at the camera but that was my surprise that was recording or not. I did not watch all the takes before sticking it all together,
and yes I was drunk and frustrated. I wasn't calling anyone a mofo, it is more of a generic remark I use to express disappointment.

[youtube]tktYayFQ5Ck[/youtube]

 

[drew12345]

Whoa! I'm sorry to see the damage to chainring. Thanks for sharing though.

 

[John Bozi]

One of the guys offered a 4th reason (he knows from experience)

4. It is not the torque but the lack of tracking on rough terrain. Suggesting that the chain has bounced off its line under load and then minced everything in its path.

This is a definate possibility that I hadn't thought of since I didn't see anything happen.

Good news after much hard work I have managed with heat to remove the chain ring and although I am waiting for the extra long nuts I can use temporarily some off my other bikes so that I can continue to work on the bike.

I am playing with the idea of how I can use something similar to the original chain retension device which will not fit as it is now, but maybe the main alu bit can be used as the main part to create something to do the rest.

It looks like I will not be riding for at least another week now.

I am also trialling the 32t and have tested with positive results if it is possible to put some of the nuts which are in the way of the chain on the outside of the ring and they do clear the crank too

 

[Gab]

I am struggling to find how to climb them with this kit. If I leave the power open to 5kw I find climbing super steep complex rough terrain uncontrollable.

So I kept trialling setting on the CA to limit power but nothing seemed doable.

The trottle is too twitchy. When you are on an incline maybe 20+, stuff where you are holding the brake lever and trying to not slide backward and then try to bring on the power, I found I couldn't manage the power level.

Take up a step back. I can do all this terrain with my tiny slow bafang motor geared to super slow. It has the perfect amount of torque in its one gear to climb everything that traction will allow. It does it at wot
so there is no thought at your hand trying to manage the power. At 10kmh there is the perfect speed to climb the point before traction loss and the terrain is always rocks here and there which must be manouvered through
so that you don't come to a stand still.

Yes the bafang would overheat if doing this continuously for over 5 minutes but it got me through to the parts where the hub could kick in again.

With the LR you have to bring on the possible 5kw slowly so you don't flip or go into a spin on what is already a hard to hop on bicycle angle.

Bike's looking really good. Looks hella fun.
Kelly controllers have the option for torque throttle I think, or CA can do that.
The three speed switch on a speed controller simply resets the max speed attainable thru the throttle, so same physical grip twist range, same watts available, but motor rpms can be limitted to whatever you want.
If top is 40mph, you could set to 50%, still get all the same watts, but have 20mph on full grip twist range. Much better modulation for slow speed while keeping power the same. Works excellent imo,

So the 5KW big block is too much power and the bafang 750w is not enough, and you needed a torque throttle controller not cheap greentech or Lyen, well that's pretty much exactly the original kit you were thinking of using isn't it the AFT 1680w ? as that kit power is right in the middle of both and it comes with a quality Kelly controller that has torque control.

And now the chainring is bent pretty much proves you cannot run above 3kw on standard bicycle parts..so even if people sell kits that say they have more power I don't think they have tested it at that power to prove it works or not... an aluminium chainring would have bent even earlier. . I think that is the reason most kits chose to stay under that power level.

 

[r3volved]

Yowza!
I've had the chain stuck between sprockets like that but I guess I caught it in time and it didn't do damage like that!
I would try one of those chain guides that has a channel on top and bottom...not sure if that lets you use two chain rings or not.

 

[John Bozi]

Actually I have pulled shy of 5kw up a bitumen road absolutely thumping the hill. So it is doable but whether it is for the rough terrain is still yet to be proven.

I did smash a steep dirt mountain in one take as well at about 30kmh which is probably the most extreme ride I have had for a long time and it blew my mind.

So although this doesn't prove to me that bicycle components can stand up to this power for long. It suggests with tweaking more things might get better.

On the note of the AFT, I am pretty sure that it still overheats right? The big block has never gotten over 42 degrees celcius and this was riding in 35 degrees ambient. It's the controller that is the limiting factor with explosive power this motor can handle.

There is no doubt that there are lots of custom bits of work to do. still.

The tensioning device will not fit as there are two many sticking out parts.

 

[ferret]

You can program the Cycle Analyst for torque control instead of speed control regardless of which controller you are using.

Avner.

 

[jk1]

On the note of the AFT, I am pretty sure that it still overheats right? The big block has never gotten over 42 degrees celcius and this was riding in 35 degrees ambient.

Overheating of any motor is more to do with the wrong gearing for the wrong loads it sees . I.e if you slow down by gear reduction any motor enough, it will handle any load. And since your motor doesn't overheat more then 42deg you said , Then it seems to bay way too much motor for what you need and you are carrying around dead weight. 60 to 80 deg is normal motor temp ranges.

And you can see in this thread even the AFT/cyclone motor if you can speed it up by putting a huge sprocket at the back, and even better small sprocket up front, will run at over 2kw continuous without cooling fins... add them it would be even better.


https://endless-sphere.com/forums/viewtopic.php?f=28&t=73027

 

[stonezone]

I can relate to your posts so much that they physically pain me....

You've got to bite the bullet and switch to single speed, 1/8 rings, or you'll keep shredding one thing after another. Add a few spacers to an old deraileur as your tensioner and you should be good for chain growth. On my setup, I couldn't run a front chainguide, but one on the chainstay has been working well.


If it would only stop raining now...

 

[John Bozi]

On the note of the AFT, I am pretty sure that it still overheats right? The big block has never gotten over 42 degrees celcius and this was riding in 35 degrees ambient.

Overheating of any motor is more to do with the wrong gearing for the wrong loads it sees . I.e if you slow down by gear reduction any motor enough, it will handle any load. And since your motor doesn't overheat more then 42deg you said , Then it seems to bay way too much motor for what you need and you are carrying around dead weight. 60 to 80 deg is normal motor temp ranges.

And you can see in this thread even the AFT/cyclone motor if you can speed it up by putting a huge sprocket at the back, and even better small sprocket up front, will run at over 2kw continuous without cooling fins... add them it would be even better.


https://endless-sphere.com/forums/viewtopic.php?f=28&t=73027

I haven't fully tested this on a full pack to the end. I have done a couple mountain climbs at most, which is still far from what I hope to do in time.

I know I can run this through all the terrain I used to do with just my hub motor and probably be fine. However, with the dual motor there was absolutely no terrain that I couldn't climb that traction allows.

Stonezone I am single speed already, just not the 1/8 yet.

I know my bike will be very slow for what most high powered bike riders are into but I literally have not many flat sections.

My original plan was to give high speeds for a gearing that can do the most extreme. If my top speed is about 30kmh on 32t x 20t and that works I can live with it.

Tempted to give it a spin this afternoon, but a bit worried about the shorter chainring nuts I put on temporarily.....

EDIT

I put it together and did a few laps around my house, makes me want to improve lots of runs a bit around dam fun and crazy.

The gearing 32t is surprisingly more controllable. I was thinking I have more torque to be scared of and well I do, but the slower speed makes it much more bearable.....

few more beers and I am going up to the testing trail.

 

[stonezone]

not sure about your trails, but here 25-30mph top speed is way more than I need 90% of the time, and for DH I'll just pedal for some more speed. On the road it seems really slow (especially when you see someone else on an ebike)... but in the trails you go from corner to corner as fast as a moto. I'm not sure if even 1/8 is strong enough when you hammah.

my motor barely gets hot, even after 20 minutes of hard single track uphill.

I really need to get some video...

 

[John Bozi]

kph vs mph big difference but I think we are on a similar style.

I just got home from another proper off road mountain trail test and sad to say the skip has returned on the rough steep parts.

On road on 32t I can unload around 3kw scream coming home I have people from far away turning around and at

1kw seems to be about the amount for flat at full throttle I can only guess just under 40kph.

This is all looking kind of sad because a hub motor as my drive train stands now is much better at pumping through complex rough terrain, I don't care what philosphy guys use to say about weight in the centre... I know from experience that raw power with no skipping chains is much more to the ground..... on the downhill no hub is better but sheesh I am all about climbing.

There are too many theories from people who havent done the four varieties on the steep off road terrain I do ....

I have tried mids with gears with low power and high power, hubs with low and high power and both combined....

For me the 32t was a huge improvement that I originally wanted. The controller was at the right temps now and I was using lower power as the cause, it felt more controllable just pissed that the skip returned....

For now I am going to use 32t until it fails (sick of blowing cash on sh*t)

but I see I will need to enlarge the rear and get a custom tensioner back there as you mentioned and as a result to keep decent riding speeds increase the front again.

cool thing was a guy came down the mountain on something looked like a legal midrive specific frame - thought he might stop but dont think he knew I was electric too.... wasnt riding

EDIT 24/11 morning

I took out the part that fastens the ss tensioner to the rear and put a couple of bolts, washers and nuts to connect it to the removable dropouts shifting the whole thing forward and up. This has gained almost a quarter of the sprocket 4 or 5t more engagement. It is make shift for now and I have tested it around my yard but to not annoy people sleeping, and the fact that we had a lot of rain last night I can't hit the testing point for now. After work it should dry up if no further rain for a quick test up there.

However, I am starting to worry about other things.

1. the reduction shaft seems impossible to get straight, theres are clear wobble and the small sprocket on it has a creak as a result.

2. The chain ring nuts heads have the same height as the originals but they have been nicking the motor under load. I don't see how a thicker chain than this wipperman is possible too as it must be nicking the motor too.

3. The back wheel looks like it was dished toward non drive side. I hope the chainstays haven't bent or the axle / hub twisted from the unnatural load. I can't confirm this has changed since I bought it as I didn't notice it but I reckon I would have looked for these things...

I am hoping these are not that important because I can't imagine the expense of fixing or replacing for now.

 

[bunya]

This thread is always on the move, exciting stuff happening. As others have mentioned, the most common torque controllers are the Kellys, though running 20s might mean only a larger one will fit. If you could set it up through the CA that would be ideal but I know nothing about them.

 

[stonezone]

Are you sure your cogs aren't slipping on the freehub body? I welded so many together that my entire freehub is literally one peice... and to top it off, i even put a couple of tacks on the end cap (so if the whole cog unit slipped, it actually would be tightening up the freehub body). I also really think the way DT-Swiss engages without splines is more solid than traditional.

send some pics... i fit a 3/16 chain and my deraileur tensioner works much better than the single speed one I tried using in the past.

 

[John Bozi]

Are you sure your cogs aren't slipping on the freehub body? I welded so many together that my entire freehub is literally one peice... and to top it off, i even put a couple of tacks on the end cap (so if the whole cog unit slipped, it actually would be tightening up the freehub body). I also really think the way DT-Swiss engages without splines is more solid than traditional.

send some pics... i fit a 3/16 chain and my deraileur tensioner works much better than the single speed one I tried using in the past.

I am not sure they arent slipping and that was one thought but I am hoping they arent.

Update: I had absolutely NO clack today, so hopefully it will stay this way. With my chain wrapped that almost 3/4 of the sprocket I imaging its now pulling the chain toward itself instead of only engaging half the sprocket.

I havent taken out life insurance but I took your advice and removed the guard which was annoyingly still rubbing.... when I had everything perfectly fitted it was before the grub screw and the warped chain ring so now its a bit wobbly and was hitting the guard.

I got it relatively quieter so pretty happy.

I am totally stoked riding it at this speed it doesnt feel slow at all. I climbed much further up my rough steep section from stand still hill starts but I am just not getting the control I had. I dont think its totally the bikes fault. I think I am not probably skilled enough at holding the twist so finely and probably should drop my seat to the lowest possible so I dont get taken up the but by the seat post so much. I like the height for pedalling on flats but on extreme uphill I like to flat foot the ground on take off and negotiation.

I just dont have the connector for the computer from CA so still doing my head in about settings.

I absolutely cant work out why my throttle registers through the Ca input but no power that way... do I need a shunt or something?

I would insanely greatful if you could list your keys setting mate.

Which throttle input etc....

 

[stonezone]

nice work! If I adjust the spring tension screw that in effect moves the deraileur pulley away from my cogs it will slip like you describe. I need as much contact as possible!