Pianoman Cromotor build on Atomlab Pimp DJ frame

[pianoman]

Cromotor with temp probe from Methods, laced in 17 inch steel moped rim, front wheel 17 inch moped rim as well, rims and spokes from JRHolmes, dmr revolver 36h front hub
Tires: Michelin Pilot Street 60/90x17 (2.25 equivalent) front, 70/90x17 (2.5 equivalent) rear, thick tubes and Slime just in case
CA V3
Cell man a123 24s6p split pack with 80a continuous bms, half in triangle, half over top tube
3 speed switch
Atomlab pimp 2 cromoly dirt jump frame with 5mm thick rear horizontal tight dropouts
9mm stainless steel custom cut torque arm on one side, 5mm on the other
Rockshox domain u-turn suspension fork set at aprox. 120mm travel, thru axle, strong single crowne, thick and firm 35mm steel stanchions,link to specs: http://www.sram.com/rockshox/products/domain-r
Avid bb7 203mm front 203 and rear 160mm rear disk brakes
Zombiess 24fet 4110 controller, programmed to 135a battery 200a phase (80v A123 battery)
Zombiess throttle tamer
Led headlights 1 high 1000lum, 1 low 1000lum, taillight with brake signal, front and rear turn signals, motorcycle horn, all works from main battery, connected to CA outlet using AC to DC converter which was power supply for external hard drive
Heavy duty double leg stand
Bag over triangle, can hold additional 9ah a123 battery or can be used for storage
Converted to single speed, 38 tooth chainring 16t sprocket, uses chain tensioner, larger surface pedals and Redline Microline 135mm crankarms for better ground clearance
Very quick acceleration, Zombiess throttle tamer very usefull for smooth takoffs
Top speed 65 km/h on fresh charge
Runs much cooler then previous modified 9c, small wheel make huge difference aside from cromotor being much stronger. In summer temps 70-80 degrees celcius in normal use, only in long and climbs can go over 100





Here is built history:
I have done 3 ebike projects so far, first 2 were 9c 9x7 48v kits on 14ah sla and 33a controller, one front with thick steel fork and other rear drive, both on xc entry level aluminium mountain bikes, by then didn’t know almost anything about ebikes. Then modified the rear drive one to 72v setup on 6 14ah sla and lyen 12fet, but bike was far too heavy, had poor handling and simply didn’t feel strong enough at 60kmh. Finally upgraded front 9x7 bike to higher voltage with lyen12fet at 30a and changed sla to 24s4p a123 from cell man, so that’s a fast but not very powerfull commuter. Then I decided to build a 3rd bike which would be higher power setup with good front suspension for fast rides on pavement and some moderate hill climb capability. This one is my latest build and has the following setup:

HS3540 motor air cooled in 26 inch wheel, 8 20mm holes on each side, actually on freewheel side 4 20mm and 4 14mm holes, was afraid to drill all 8 at 20mm thinking the cover could become too weak
Stock phase wires, but with 8awg extension from axle to controller
Lyen 24fet 4110 controller
Cell man a123 24s6p split pack with 80a continuous bms, half in triangle, half over top tube
large screen CA
Temp sensor
3 speed switch
Atomlab pimp 2 cromoly dirt jump frame with 5mm rear horizontal tight dropouts, here's link to specs http://www.atomlab.com/mtbframep2.html
9mm stainless steel custom cut torque arm on one side, 5mm on the other
Rockshox domain u-turn suspension fork set at aprox. 120mm travel, thru axle, strong single crowne, thick and firm 32mm steel stanchions,link to specs: http://www.sram.com/rockshox/products/domain-r
Avid bb7 203mm front and bb5 160mm rear disk brakes
Atomlab pimp rim, sapim 12g spokes on rear wheel
maxxis hookworm tires with downhill tubes and slime
11-32 7 speed freewheel
65tooth chainring (for pedalling at 70 kmh!)
Lights, air horn, etc.

View attachment 10View attachment 7View attachment 5


First when bought the motor, I thought I have a 5304 winding and stupidly enough on first test gave it WOT acceleration from still going uphill, as a result in a minute lyen 18fet failed on 60a 150a phase settings, melted phase wires (had not extensions from axle to controller then), overheated motor as well. Then opened and checked the motor, fortunately no damage within it, just some rubbed wires because of axle and side cover design, fixed that removing rubber seal, did phase extensions, drilled holes, upgraded to 24fet and installed temp sensor. After doing some research I now accelerate very gently off line, but give some strong power bursts after reaching about 35kmh and it feels very powerfull at 60a battery, left phase at 115a for now.

I started to suspect the motor not being a 5304 as known from 1st generation, it looks like HS3540 which is between 5304 and 5303 rpmwise, being a bit less hard on controller I guess, at least compared to 5303, that’s a good thing, but maybe HT would have been better eventhough it is a bit too slow at 80v, but closer to my needs then HS. The good thing about it is an excellent mechanical fit, no dishing what makes a stronger wheel, easy disk brake and freewheel fit and less weight.

Would you recommend to swap for HT3540 to have less overheat? 60 kmh top speed is my target, with HT it would be slightly less, but I can live with that if it would have much less overheat issues compared to HS.

Update:
Just drilled some more holes on disk rotor side for air output, it proved to cool much better this way, only thing is that temp reading now is not so precise as cooling affects it directly, according to temp probe temp rises about 10-15 degrees Celsius when I stop (I guess that's because temp sensor is on windings but close to cooling holes, so I normally add 10-15 degrees to the reading I see when in movement), but anyway now I can go 63 kmh constant (about 2200-2500w) with some 3000-4000w on short uphills and temp stays around 100 degrees or less, before it didn't stabilize around 100 and was slowly rising when 63kmh, hottest I let it get was 125. Tests are done with 27 degrees ambient, dry, almost no wind. Controller settings are 65a battery 115a phase, speed 3 (fastest) set to 57 %. Controller temp gets to 50 celcius aprox.

 

[miro13car]

Are you serious about those holes in motor?
So yours is " No-Rain" ebike, right?
No riding in rain,or you still can ride with rain water on windings extra cooling them down? LOL :lol:

 

[pianoman]

Are you serious about those holes in motor?
So yours is " No-Rain" ebike, right?
No riding in rain,or you still can ride with rain water on windings extra cooling them down? LOL :lol:

Extra cooling with rain water, that's a good one LOL!
It's a no rain bike of course, I don't like to ride in rain and it's more a hobby then commute vehicle, so I ride when the weather is good and I have time for it. I'm not sure if holes help a lot while pushing it, but definitely it cools down a lot faster when I back off power or stop, and that's good too.

The question is, would more holes help to be able to pull more power without it overheating, as now I have it done Doc's suggested way, on one side output holes near the outer cover edges and on the other holes closer to center for air input. I'm wondering what would happen if had both input and output holes on both sides, would it be better or worse and would structual integrity suffer? Somehow have a feeling that holes near the outer edges on freewheel side too would help a little more, but I'm not sure about it.

 

[veloman]

You would be wayy faster if you forgot about pedaling at 70kph and instead had a lower handlebar and/or tuck in at those speeds. Even at 45kph i am more efficient if i tuck rather that pedal normally.

 

[oatnet]

Are you serious about those holes in motor?
So yours is " No-Rain" ebike, right?
No riding in rain,or you still can ride with rain water on windings extra cooling them down? LOL :lol:

Miro, holes in the sidecovers a standard practice here, when hot-rodding motors. It allows the motor to shed a lot more heat, so you can put more amps into it, not sure how you could have been here for the past few years and not seen it everywhere. Heck, how could you have missed Lukes 'penis motor' where the holes were shaped like genetilia? Rain, gravel, and dust have proven to not be an issue. In '06 Steve Head had video running submerged hub motors down a creek/river. Salt water would be a problem, but clean water does not conduct current very well.

 

[nicobie]

An HT3525 will get you 40+ mph in that bike. and most likely never overheat.

Mine goes 40 mph if I go into a tuck and that is with 24" wheels w/2.5" hookworms. I have a hard time getting the motor over 80C (temp probe on windings)

 

[pianoman]

You would be wayy faster if you forgot about pedaling at 70kph and instead had a lower handlebar and/or tuck in at those speeds. Even at 45kph i am more efficient if i tuck rather that pedal normally.

Hi Veloman, I know it would be much more efficient and generate less heat if I tucked, the thing is I have back and wrist problems, that's why I choose upright riding position eventhough I know it has very poor aerodynamics. Ideal solution on pavement for speed is a low recumbent, excellent aerodynamics, but I don't have one, those are fairly expensive and not so good uphill or offroad, and very scary being that low and watching trucks passing closely...
Anyway now with more cooling holes the temp at 63kmh is stable around 100 degrees or less. Controller settings battery 65a phase 115a, 24 fet is getting pretty warm around 45-50 degrees celsius. 3d speed setting is 57 percent, that gives around 63 kmh top speed. 100 % speed setting draws crazy current up
untill 70 kmh, that would probably damage motor and controller soon.

 

[Andje]

just to put your worries into more perspective; I don't think you have to worry about that controller temperature at 50 degrees, and I wouldn't worry about my motor temp till it started creeping up towards 120 degrees. I killed two HS 3540 with an 18 fet at 100v 80 amps, so I would at this stage advise keeping those motors to about 7500 Watts if you want longevity. Neither of mine died at peak levels, just running them close to the edge killed them within a couple weeks. A lot of the heat is generated in hard acceleration, so if you accelerated normally from a stop every time you will see less heat build-up in the motor (sounds like your doing this); on the same daily commute my riding style makes all the difference in how hot all my components get. I find it no problem to accelerate up to traffic speeds far faster then a car but still far slower then the bike is capable of; if i gun it too hard it just flips me off the back anyway .
Finally, I, like you, thought x5 for my needs. I then went through a cheap 9c, two hs35's and then finally grabbed an x5304. The hs's were faster at 110km/h, the 9c was lighter and still did 90+km/h, but my x5304 does about 95 km/h and can take my entire battery pack (100v 15ah) at wot without burning. So I do think that if you find yourself pushing that hs up to 110+ over and over I would be looking for a cheap x5. They are harder to find, but comparing them to HS/9c they have far more metal inside to heat and take far longer to reach danger temperatures. The windings are thicker too, so less chance of the enamel boiling off and shorting the phases. Probably have to compete for a second hand one though, they are getting much harder to find since being replaced by the hs series.

 

[pianoman]

just to put your worries into more perspective; I don't think you have to worry about that controller temperature at 50 degrees, and I wouldn't worry about my motor temp till it started creeping up towards 120 degrees. I killed two HS 3540 with an 18 fet at 100v 80 amps, so I would at this stage advise keeping those motors to about 7500 Watts if you want longevity. Neither of mine died at peak levels, just running them close to the edge killed them within a couple weeks. A lot of the heat is generated in hard acceleration, so if you accelerated normally from a stop every time you will see less heat build-up in the motor (sounds like your doing this); on the same daily commute my riding style makes all the difference in how hot all my components get. I find it no problem to accelerate up to traffic speeds far faster then a car but still far slower then the bike is capable of; if i gun it too hard it just flips me off the back anyway .
Finally, I, like you, thought x5 for my needs. I then went through a cheap 9c, two hs35's and then finally grabbed an x5304. The hs's were faster at 110km/h, the 9c was lighter and still did 90+km/h, but my x5304 does about 95 km/h and can take my entire battery pack (100v 15ah) at wot without burning. So I do think that if you find yourself pushing that hs up to 110+ over and over I would be looking for a cheap x5. They are harder to find, but comparing them to HS/9c they have far more metal inside to heat and take far longer to reach danger temperatures. The windings are thicker too, so less chance of the enamel boiling off and shorting the phases. Probably have to compete for a second hand one though, they are getting much harder to find since being replaced by the hs series.

Thank you Andje, I believe you know now about hs3540 after killing 2 of them
How did they fail, windings burned, shorted, phase wires melted, halls?
For sure 5304 would be a better choice for me, perhaps even 5305 as I don't need top speed higher then 60kmh at 80v. In case of Hx I guess HT would have been better choice for me, acceleration in middle speeds would put less stress on phase wires and controller and maybe it would heat up less too at same torque and speed levels as HS as it seems from ebikes.ca simulator HT is a little more efficient at lower speeds thgen HS. Maybe I'll try to find a x5 one day, especially if this HS fails. For now it's ok, I don't do hard accelerations normally and never from dead stop, at current settings peek power while accelerating from around 40kmh is 5000w, I don't think I'll go higher then this, thinking also about frame, torque arm, spokes and rim, 5000w is enough stress allready I guess and it's enough for me.
Could you comment on stock phase wires of HS? What about stock bearings? Well, maybe in your case couple of weeks were not enough to test bearing longevity anyway...
By the way, is front wheel with 203 disk brake rotor strong enough with 14 gauge spokes on 32 hole thru axle hub? Front rim is strong, but not the toughest like I have in rear wheel where motor is. Would you recommend to switch to stronger rim/thicker spokes and maybe 36hole hub in front or it's not necessary? I don't do offroad and don't hit potholes. Just concerned about battery weight, I have 24s6p a123 which are a bit heavy and also about front braking with 203m rotor which puts a lot of stress on spokes, hub and rim I guess.

 

[rojitor]

in'06 Steve Head had video running submerged hub motors down a creek/ river. Salt water would be a problem, but clean water does not conduct current
very well.

do you have the link for that video please?

 

[Andje]

in the end I would say that the front wheel takes 10% of the abuse the rear does and doesn't require super significant upgrades. I upgraded to 203mm in my front and found that with that and rear regen i needed no other brake. I have since added a rear v brake to be able to lock the wheel, but I don;t use it to slow down and still find myself able to stop in about 15 feet from 90km/h on front disk and regen alone.
I can't comment on the bearings; i replaced my 9c with good ceramic ones but the hs's i ran stock. I had trouble with the wire cutting issue, but what killed them in the end was phase shorts from the enamel burning off; I have never personally had a problem with phase wire heating but my controller is about 10 inches from my motor by wire and I've always run 8 gauge to the motor, and I've tried both upgrading and leaving the phase wires; it never made much of a difference to my observations. Both died around 4000 watts but took peaks of 8500.
If you're around 5000 watts peak and don't have more then a 1500w/h pack then I prbly would say the x5 is too heavy to be practical; especially if you like to pedal and don't accel from a dead stop. I don't pedal at all lol. The x5 is basically a motorbike engine, although i got similar performance from the other motors they just didn't last as long.

 

[pianoman]

in the end I would say that the front wheel takes 10% of the abuse the rear does and doesn't require super significant upgrades. I upgraded to 203mm in my front and found that with that and rear regen i needed no other brake. I have since added a rear v brake to be able to lock the wheel, but I don;t use it to slow down and still find myself able to stop in about 15 feet from 90km/h on front disk and regen alone.
I can't comment on the bearings; i replaced my 9c with good ceramic ones but the hs's i ran stock. I had trouble with the wire cutting issue, but what killed them in the end was phase shorts from the enamel burning off; I have never personally had a problem with phase wire heating but my controller is about 10 inches from my motor by wire and I've always run 8 gauge to the motor, and I've tried both upgrading and leaving the phase wires; it never made much of a difference to my observations. Both died around 4000 watts but took peaks of 8500.
If you're around 5000 watts peak and don't have more then a 1500w/h pack then I prbly would say the x5 is too heavy to be practical; especially if you like to pedal and don't accel from a dead stop. I don't pedal at all lol. The x5 is basically a motorbike engine, although i got similar performance from the other motors they just didn't last as long.

Thanks Andje, that's more or less what I thought too, what I really like about Hx motors is freewheel and disk brake fit and no dishing necessary, also the weight. We'll see how it 'll last, but for 60kmh with cooling holes seems to be a good option.
I've never seen in real life a x5 motor, just pics, I guess I wouldn't mind the extra weight, bike is rather heavy now anyway, anyway I just like the idea of x5 being more robust, thicker windings, more mass, would take longer to heat up (but also to heat down). And then there's a Cromotor, which I understand is even a tougher performer than 53xx or even 54xx. I just don't like the idea of not being able to use the freewheel with 11 tooth sprocket on these bigger motors (54xx and cromotor) because of wider stators, as my bike has 135mm dropouts (and at least cromotor is pretty expensive as well...). And with those motors it's probably allready more of a motorcycle territory, then to get out most of them I'd prefer a motorcycle frame-fork, thicker motorbike tires, smaller motorbike rims and thicker spokes, basically if such power, I'd prefer to have a motorcycle as a platform with lower riding height, full suspension, comfortable seat, etc...
By the way, 203mm front disk brake works great even when used alone, but regen helps quite a bit and rear 160mm disk brake is very helpfull as well, that means a little less load on front wheel while braking, and also shorter braking distance when used hard. When I used just rear regen having a rear 9c without disk adapter, I had to brake harder with the front wheel, now HS3540 with rear 160mm brake + regen, the front wheel can be a little more relaxed.

About the bearings, when they are failing is there a noise to detect the failure? Or the wheel just doesn't turn as smoothly? How long the stock bearings would last, any idea? I hear some growling and resonances at low rpm when giving more power, with small power it's relatively quiet, but at higher rpm the noise goes away, so I'm not sure if the bearings can cause some of this low rpm noise, maybe it's just normal.

 

[Andje]

if you mean the sort of almost grinding noise under loaded accel then it is just resonance in the hub motor; with a good gopro you can still hear that noise above 30 km/h in video, its just at a higher frequency as the rpm rises and gets harder to hear on the bike since the wind noise dominates it. I have experienced this noise accross every motor i have to varying degrees; the x5 is actualy the most silent because of it's stator design; it is less efficient (slightly) but audibly quieter and slightly smoother upon accel.

[youtube]p_gpp9q6-YE[/youtube]

this is a speed run i did on an hs motor; is the noise similar to what you hear right at the beginning?

 

[oatnet]

the x5 is actualy the most silent because of it's stator design...

The most silent DD hub motor (actually completely silent) is on the Tidalforce/EMS+, because it uses a different control scheme, so the controller does not generate those resonate frequencies. The x4 is the next quietest, then the x5, then the 9c.

-JD

 

[pianoman]

Being curious about how this motor would hold up to higher power, I programmed my 24fet to 80a battery 120a phase (insted of 200a phase which would be using the the usual ratio of 2,5). My idea was to use settings that would would prevent applying too much power at low rpm, but have full power at high rpm. According to ebikes.ca sim, for this motor at battery amp setting 80a phase amps are around 120a when accelerating wot from 38kmh with my setup, so that's the speed from which the full acceleration potential is achieved.
I programmed phase current limit to 120 to preserve the stock phase wires on my hs3540 within the axle (outside they have thick 8awg extensions, so no problem outside the motor). I think this setup 80a/120a along with setting block time to 1 kind of prevents killer starts offline that would quickly melt the phase wires and overheat the motor as below 38kmh at 80a battery phase amps are getting very high multiplications, I guess limiting phase amps in software I get around this low rpm problem getting good high rpm power the same time. Eventhough mild torque at low rpm with this phase current limit, acceleration gradually increases as the speed goes higher, and through the 40-75kmh acceleration is awsome, in CA it shows up around 6000w at full throttle when in this speed range (but less watts at lower then 38 kmh speeds when WOT).

I now changed my speed settings to speed 1 40 %: 45kmh, speed2 50% 55kmh, these two are for cruising, but speed3 now is 99% that gives me around 75-kmh depending on wind conditions. Of course, I'm not using it at 6000w constantly, just for about 30sec continuous, this setting is for fun, not long distance cruising.

Still, I don't know about the stock phase wires within the axle, are they in danger to melt when using short (about 30 seconds) powerfull accelerations in 80-120 phase amp range? Or it just depends from how long I use full 6kw and how often? Overall I watch motor temp and never let it go higher then 120, generally it reaches 110 celcius max.

 

[pianoman]

if you mean the sort of almost grinding noise under loaded accel then it is just resonance in the hub motor; with a good gopro you can still hear that noise above 30 km/h in video, its just at a higher frequency as the rpm rises and gets harder to hear on the bike since the wind noise dominates it. I have experienced this noise accross every motor i have to varying degrees; the x5 is actualy the most silent because of it's stator design; it is less efficient (slightly) but audibly quieter and slightly smoother upon accel.

[youtube]p_gpp9q6-YE[/youtube]

this is a speed run i did on an hs motor; is the noise similar to what you hear right at the beginning?

Nice vid Andje, certainly fast!
Besides the "grinding" noise my motor has a different noise which only happens at certain middle-low rpm, I'll try to record and post it. When doing a no load test with the wheel lifted, I can intentionally make that noise continuous in very exact rpm, but it discontinues if I change rpm. I wonder if it can be bearing related.

 

[Andje]

i have also noticed a particular noise now that I have my x5; the x5 has angled teeth that reduce the grinding noise you hear in the vid i posted. As a result, the loose spokes make a particular creaking tightening sound that can be heard before the wind takes it away as you gain speed. I don't think I could make it continuously though, so it may not be comparable.

 

[pianoman]

i have also noticed a particular noise now that I have my x5; the x5 has angled teeth that reduce the grinding noise you hear in the vid i posted. As a result, the loose spokes make a particular creaking tightening sound that can be heard before the wind takes it away as you gain speed. I don't think I could make it continuously though, so it may not be comparable.

I know what you mean, with my 9c wheel I hear spokes creeking as well, but my hs3540 wheel has 12 gauge spokes and semi radial lacing, spokes don't make noises as they don't rub against each other. Any way the noise I'm talking about is differtent.

Bad news. Today when riding I noticed the temp rising much faster then normal and it didn’t cool down if I continued riding at low power as it did before. So I stopped, let it cool off, then was riding gently around 1000w again, but temp again was rising over 100 celcius even at such low power. Checked lifting the wheel and giving no load acceleration, even at this condition temp was rising. And at mid rpm ther was a dry metallic scraping noise. Wheel was not hard to turn, but not as smooth as normally. Brake was not locked. Checked if wheel was loose somewhere and yes, at the freewheel side there was some movement between stator and side cover. Suspecting damaged bearing, opened the motor and yes, the bearing was bad, very loose and has to be replaced. Maybe because of that bearing there was some friction between stator and rotor too which caused quick heating up.
I don’t know if the bearing was too low quality or I was not carefull enough when taking off and putting back the side cover when did the air cooling mod previously. Freewheel side cover first time was very difficult to get off, I had to use soft rubber hammer to get it off, and side cover came off alone with the bearing remaining on axle. When I took apart 9c this didn’t happen. I have read somewhere that bearings have to be treated with pressure and not impacts, but I didn’t have press available, so I used rubber hammer very gently.

http://youtu.be/ZiyPdF8RiEw

In vid you can hear that metallic noise. There is another noise of disk brake rotor too, but that doesn’t matter, that is due to disk rotor wobble because of not exact machining of the side cover. The freewheel dances up and down as well when doing no load acceleration with wheel in the air, this side cover seems poorly machined as well. Doesn’t happen on my 9c.
There was another noise as well which I cannot record as it happens when motor is hot around 110 celcius, it is at low rpm and I feel strong vibration which is transferred to all bike, but the sound is soft. That vibration is present at low rpm with hot motor whether pedaling with power off or power on.

Now I have to find replacement bearing. Hope that will resolve the problem.

 

[Andje]

ouch, yeah that does sound like bearing.first time I heard of video of that particular problem. gl finding some new ones!

 

[miro13car]

Oatnet,
you are very, very right
E+ uses Space Vector Pulse With Modulation which uses complex calculations to determine exact times to feed pulses into motor electromagnets based among other factors on mutual orientation of rotor and stator magnetic fields.
Vector is a mathematical tool to model magnetic field in the space showing strenght and direction of magnetic field.
All calcuation is made TInstrument DSP chip.
E+ motor being only 3-phase is smooth enough, but 7-phase TF motor is silky smooth and very, very predictable. Yes as you said both are completely silent no matter how hard pushed,
both are electrically /by overvolt, overcurrent , over temp./ impossible to distroy. They will not allow you.

 

[Andje]

We just think your opinion is entirely based around your own opinion, and we have ample evidence documented to prove you are wrong.
If you can't wrap your head around cooling holes, just think of an oven. What happens when you open the door of an oven? It would take longer to heat to 300 degrees with the door open, right?
Pebbles don't make it in; if they did some window screen with glue over the holes would solve it but it is unnecessary. Dust doesn't hurt it. Moisture gets in anyway; draining it well is preferable then letting vapour condense.

 

[miro13car]

what is he talking about,maybe you should put your head in the oven?

 

[Andje]

im just going to say;

Troll.

 

[pianoman]

For now changed to an old model 9c 9x7 on 80v with cooling holes, pretty good winding for my needs, nice mid speed acceleration, I run it 55a battery 110a phase and it's pretty quick. Don't feel much difference between this 9c and Clyte HS that is broken, other then top speed, and 9c 9x7 is much easier on controller. No rear brakes other then regen, but it actually works well when combined front 203mm brake. Regular rear 2.1 slick tyre I was using weared out very quickly, so another reason why moped tyre a better choice for accelerations and high speeds, eventhough hookworms are much better wearwise then regular slick, but for now can't use hookworm while waiting for right spokes to arrive to redo the wheel, the too short ones I have didn't let do enough dishing, so wheel is not dished at all and very off center.
I think before looking for 53xx, 54xx or cromotor I'll see first how 9c will hold up, for now I can ride it 50-55kmh continuous vented, being 60 top speed, more then that and it overheats too much, but 50-55 kmh for my needs is actually good speed. The road I use for fun rides is very smooth, going 70-80 kmh with just front suspension no problem, not much trafic either. Unfortunately most streets here suck, have to go 20-30 kmh on this hardtail ebike, if not it just feels too bumpy and uneven. Rear susp might be better, but then not that much room for batts, plus more expensive.