Ut Oh Cooked Another

[john61ct]

I'm not insisting on anything, just asking for feedback exploring ideas.

As above, since it is so cheap and easy to adjust the motor-output gearing, I'm thinking to use that to ensure the Rohloff max tolerance of 130 N.m is not even approached, perhaps in combination with a CAv3 enforced throttle-control limitation.

That will then determine final wheel speed range top and bottom, which I suspect will be infinitely better than my previous expectations attempting this with DD hubs only.

I just don't see a downside other than price.

> IGH gears, the second gear of a 3-speed is the strongest one out there. Of course that would not give you much of a gear-spread.

But it might be good enough while I'm saving for the Rohloff. And, do you mean even stronger than the Rohloff? The lowest gear is where the torque will be highest though, I'd hope speed would be up to at least 5-7mph before the 1-2 shifting would be appropriate. . .

____
Thanks for that extra bit on #215. Can that be used for standard derailer type gearing too? Or just with setups like the Lightning Rods?

 

[John in CR]

My only issue with the go-kart chains is the noise. That small pitch means more teeth are engaged on every revolution. I value silence too much, near the top on my list of priorities.

Another option if you value silence like I do is to use a high Kv big hubmotor as a mid-drive, and gear it down so the resulting gearing is like the motor was in a tiny wheel. Run a 20s or 21s pack and top speed can be sufficient (as long as you don't want really high speed) while still giving you serious hill climbing ability. With heavy duty BMX bicycle chain and dual tensioners (top and bottom) you can have near silence as well as regen with the durability and simplicity of a single speed.

That's what I'm doing with my current on/off road build I just started, with a HubMonster near the swingarm pivot and 21" moto wheels to smooth out the bumps, and I plan to run a 28t:57t reduction using moto chain for the equivalent of running the motor in a 13.5" OD wheel. That should net me a top speed of about 90kph with no field weakening and 100% speed setting. I've blasted up continuous 20% grades with numerous switchbacks with the motor in a 19.25" wheel at a max temp of 100°C, so with my ventilation plan that exceeds any cooling I've done before it should have no heat issues whatsoever running as hard as I dare.

 

[john61ct]

That sounds good!

Quiet is good I agree.

I'm not that convinced about regen for the sake of extending range

but believe it will be the best solution for safely drag braking a heavily loaded rig down long steep grades.

To the point I'd be willing to burn off excess as heat to resistors in the airstream if that's more effective than putting it back into the pack.

I have to say the clean looking engineering of the Lightning Rods is attractive.

I'm not (yet) a welder, and would prefer a clean OTS finish.

 

[amberwolf]

Not surprised by a few of those roasts, but you'd think the big muxus would have lasted, even on 72v 40 amps.

if it's the mxus 3k (450x) then it's really only good for 3000w in a 20" or smaller wheel, and even then if you run it under high load at low speed...it's like any other motor, it doesn't like it much.

 

[markz]

Justin said he got 10-15% riding around in Calgary, AB when he did his cross country tour. He also got 20-25%+ in the mountains going downhill.
Regen for braking which saves on brake pad cost. I heard some people hardly use their brake pads.

I'm not that convinced about regen for the sake of extending range

Arent 21" moto wheels rare? Thats what I read somewhere.
Equates to 26" bicycle diameter.
I'd sure love to see your hub motor as a mid drive, that'll sure be a dream to ride. You putting in a freewheel system, I guess it doesnt matter with you as your strictly throttle, pedals are for show.

Another option if you value silence like I do is to use a high Kv big hubmotor as a mid-drive, and gear it down so the resulting gearing is like the motor was in a tiny wheel. Run a 20s or 21s pack and top speed can be sufficient (as long as you don't want really high speed) while still giving you serious hill climbing ability. With heavy duty BMX bicycle chain and dual tensioners (top and bottom) you can have near silence as well as regen with the durability and simplicity of a single speed.

That's what I'm doing with my current on/off road build I just started, with a HubMonster near the swingarm pivot and 21" moto wheels to smooth out the bumps, and I plan to run a 28t:57t reduction using moto chain for the equivalent of running the motor in a 13.5" OD wheel. That should net me a top speed of about 90kph with no field weakening and 100% speed setting. I've blasted up continuous 20% grades with numerous switchbacks with the motor in a 19.25" wheel at a max temp of 100°C, so with my ventilation plan that exceeds any cooling I've done before it should have no heat issues whatsoever running as hard as I dare.

 

[john61ct]

Justin said he got 10-15% riding around in Calgary, AB when he did his cross country tour. He also got 20-25%+ in the mountains going downhill.
Regen for braking which saves on brake pad cost. I heard some people hardly use their brake pads.

Both those factors are "might be nice" but for me the motivation is fear, purely safety, just cannot be done otherwise.

They just don't design bike braking systems for constant drag-braking for speed control on very long steep descents, even a challenge for lightweight tandems, never mind heavy cargo rigs.

No matter how you do it, you're generating lots of heat that needs dissipating, can over-heat rims which can lead to melted tubes, melted rim strips and tire blow-outs.

A set of 1kW ceramic or aluminum cased resistors is one idea, but they'll leave you branded if you touch them accidentally, melt or burn through clothing.

 

[dogman dan]

Thanks for the clarification, hot day, ride around till the motor is at a pretty hot equilibrium temp, then run it up a steep hill. It (the big muxus) didn't melt in 20 min riding. It did take a while. The problem is mostly the load up that hill, but starting up it already hot was the last straw for that motor.

A good starting point for something that will last would be to build a frame that carries a big motor, but 20" rim. John pioneered this approach with his scooter wheels, but the start of it was fabricating a custom swing arm to go on a regular mtb. Then he could fit his monster motors. it just really helps with big loads, to go with the 20" drive wheels, even if its going to be a mid drive. There are cargo bikes out there with 20" rear wheels, but pricy.

I had been pretty short on cash for some time after illness retired me early, so for me it was a cheap welder, and learning to weld, well sort of. After some practice on various junk bikes, I took a very good frame, cut it in half, and built this.

If welding is not going to happen for you, maybe look for something like this.

 

[HK12K]

Roasting that mxus was unfortunate. If you get another (though I'm fond of my qs205 4t so would lean that direction personally) you really should try to get some temp monitoring going, preferably with automatic rollback.

You also might try a more powerful controller, as counterintuitive as it might seem. By only feeding that motor 40 amps it was laboring to get you up that hill and the longer it labors the hotter it gets. If you had 2 or 3 times that amperage available you could scoot up the hill more quickly and ultimately end up with less heat soak in the process. There's definitely a balance to it though because too much will also cause overheating.

I learned this first hand by fiddling with the Adaptto in the summer months, minus the roasting motors part. I was playing with power profiles searching for a quasi legal setting and found that it was just as easy to get my motor hot enough to worry about at low power levels as high. Perhaps easier even.

There is a bridge just down the road from me with a long climb. Not the steepest, probably 6% or so, but it goes on for a while. Long story short at 40 or 60 amps, creeping along on a warm day, the motor temp was to the point of concern before I even crested the hill. However after edging those numbers up I got to the point where I can cross that bridge without the motor laboring and without generating an excessive amount of heat while still traveling at roughly the same overall speed. Or much faster if I desire.

I use that bridge as an example, but I climb far steeper without issue unless ambient temps are really up there. Plan on adding ferrofluid and hubsinks this summer to give me a little more heat shedding ability.

You're a bit heavier than I am, but I suspect my bike and cargo weigh a bit more than yours so perhaps not too far off. Frankly I don't think I'd be content with anything less than 100 battery amps available. As it is now I ride around at 150 battery 230 phase in my "normal" profile with a reasonable speed limit set (more than 32, less than 50) and have all the power I need without suffering overheating unless I'm hammering it uphill offroad. Much more than 230 phase and heat becomes an issue again so that is where I tend to keep it unless I pop into boost mode, which heats things up in a hurry. Oh and when first powered on it defaults to eco mode, which is set within legal limits and is perfect for walk-of-shame-assist.

 

[999zip999]

Yes melt those 9c ez. Melted a 3,000 v1 steel stator at 7,200 watts. Now have a muxus 3,000 v3 aluminum stator at 4,800 watts . It stays cool so don't worry and 43mph is enough. I do have a car v3 not installed yet for temp.
I'm looking at middrives gng and ? I would hate the noise . As I live at the beach So Cal I need to fly under the radar. I can't have some Frankenstein rat rod. Mad max-style.

 

[John in CR]

Arent 21" moto wheels rare? Thats what I read somewhere.
Equates to 26" bicycle diameter.
I'd sure love to see your hub motor as a mid drive, that'll sure be a dream to ride. You putting in a freewheel system, I guess it doesnt matter with you as your strictly throttle, pedals are for show.

The parts shop I frequent have a decent selection. I found a pair of road and trail tires that I hope aren't too noisy on the street, and the OD ends up about 27.5".

No freewheel and no Pedals? I love variable regen with thumb throttle control, and no pedals are required here. They wouldn't make any sense at all, especially if I decide to put the dual Thermo Nucular 24's on this build, which would enable me to go to 40kw+ peak input. I think the dual 12's will be enough with this low gearing, and then I can put the dual bad boys on my Big Red scooter and add "The Motorcycle Slayer" to its name. It's currently running dual Nuc 12's quite nicely. Since the motor is in stock form, I'd need to use the speed switching (that also includes separate current limits on Nuc's) to only use the extreme current limits for red light launches. I didn't have a more recent pic since I still haven't made a battery cover, but here's one during construction when I initially made it 2wd with dual HubMonsters, but didn't like the handling with the heavy wheel and fat tire in front. It handles and rides great with a 16" moto wheel now on front, though I need to watch motor temps in the mountains. It's a fun workhorse around town with top speed of 130kph (no field weakening and speed at 100%) with 100km+ range cruising at 70-80kph.

 

[HK12K]

Jon, what kind of battery are you running in that bad boy? That range at that speed is a beautiful thing.

(Oh, and I concur about wheel size. Running a 16" in back and a 17" up front with 3.0 IRC tires on both. No desire to change it up.

Agree about variable regen too. Absolutely love it. The physical brakes are pretty much there to bring it to a complete stop but the first 99% of deceleration is provided by regen. Besides saving on pads it just seems to work better at getting the bike slowed without upsetting handling or requiring modulation, in my experience anyway.)

 

[markz]

Yes melt those 9c ez. Melted a 3,000 v1 steel stator at 7,200 watts. Now have a muxus 3,000 v3 aluminum stator at 4,800 watts . It stays cool so don't worry and 43mph is enough. I do have a car v3 not installed yet for temp.
I'm looking at middrives gng and ? I would hate the noise . As I live at the beach So Cal I need to fly under the radar. I can't have some Frankenstein rat rod. Mad max-style.

Yeah I will go back to mxus 3kw or QS equivelant if the price is right, but probably mxus since that was my cherry popper.

With that kind of power I can see why you need to fly under the radar. Total heat score.



CR - Them shocks are too much bling bling.

.

HK - Yeah it was very unfortunate. Temp monitoring is what I am currently looking into. BBQ probe would suffice, and I do want to add Statorade fluid to motor, as a safe guard.
The problem was obviously the "toy" motor, not enough mass but also a major problem was the fact I did not have proper bicycle gearing with having only one gear on the last cook. Having even 1x7or8 is a dream, can pedal at speed or pedal up a hill. Guess I was too used to suffering on the pedal gearing aspect.

Roasting that mxus was unfortunate. If you get another (though I'm fond of my qs205 4t so would lean that direction personally) you really should try to get some temp monitoring going, preferably with automatic rollback.

You also might try a more powerful controller, as counterintuitive as it might seem. By only feeding that motor 40 amps it was laboring to get you up that hill and the longer it labors the hotter it gets. (Markznotes - last 9c setup was 36V26A, so weak, needed lots of pedaling)If you had 2 or 3 times that amperage available you could scoot up the hill more quickly and ultimately end up with less heat soak in the process. There's definitely a balance to it though because too much will also cause overheating.(Markznotes yeah, I hear you on that

I learned this first hand by fiddling with the Adaptto in the summer months, minus the roasting motors part. I was playing with power profiles searching for a quasi legal setting and found that it was just as easy to get my motor hot enough to worry about at low power levels as high. Perhaps easier even.

There is a bridge just down the road from me with a long climb. Not the steepest, probably 6% or so, but it goes on for a while. Long story short at 40 or 60 amps, creeping along on a warm day, the motor temp was to the point of concern before I even crested the hill. However after edging those numbers up I got to the point where I can cross that bridge without the motor laboring and without generating an excessive amount of heat while still traveling at roughly the same overall speed. Or much faster if I desire.

I use that bridge as an example, but I climb far steeper without issue unless ambient temps are really up there. Plan on adding ferrofluid and hubsinks this summer to give me a little more heat shedding ability.

You're a bit heavier than I am, but I suspect my bike and cargo weigh a bit more than yours so perhaps not too far off. Frankly I don't think I'd be content with anything less than 100 battery amps available. (Markznotes yeah I know, especially for hills, I've been thinking about that, as I can limit cruising or can I, throttle tends to go more by no other means of limitation then myselfAs it is now I ride around at 150 battery 230 phase in my "normal" profile with a reasonable speed limit set (more than 32, less than 50) and have all the power I need without suffering overheating unless I'm hammering it uphill offroad. Much more than 230 phase and heat becomes an issue again so that is where I tend to keep it unless I pop into boost mode, which heats things up in a hurry. Oh and when first powered on it defaults to eco mode, which is set within legal limits and is perfect for walk-of-shame-assist.

 

[John in CR]

Jon, what kind of battery are you running in that bad boy? That range at that speed is a beautiful thing.

(Oh, and I concur about wheel size. Running a 16" in back and a 17" up front with 3.0 IRC tires on both. No desire to change it up.

2017 Chevy Volt modules from a car with less than 10 miles on it. 21s cells in total. 3 removed without too much trouble unlike the early model packs with the balance tap wires inside the module instead of right on top.

Regarding tires, even my MadAss conversion has fairly small wheels, so I'm really looking forward to the ride of the mid-drive with big diameter wheels and plush suspension, along with enough range to explore paths where all paved mountain roads end.

 

[John in CR]

CR - Them shocks are too much bling bling.

Maybe, but they didn't have black or silver on sale, and they make it ride like a big old 70's Cadillac

 

[markz]

CR - Them shocks are too much bling bling.

Maybe, but they didn't have black or silver on sale, and they make it ride like a big old 70's Cadillac

Sounds cush

 

[HK12K]

. (Markznotes yeah I know, especially for hills, I've been thinking about that, as I can limit cruising or can I, throttle tends to go more by no other means of limitation then myself

I find self regulation with speed can be a funny thing. When you don't have quite enough power on tap one might tend to keep the throttle mashed to accelerate as quickly as possible and keep up momentum, slowing as infrequently as possible. Like how most pedal bikers tend to ride.

On the other hand though when you have enough on tap to out accelerate cars to the actual posted speed limit you quickly realize that with great power comes great responsibility. For one, the idea of that styrofoam cup of a bike helmet striking a curb at 70kmh makes ya think. But the presumed illegality and knowledge that if you get caught you're boned is ever present. Do 50 in a 50 and you're asking for it. Lift the front tire through an intersection, same. A high powered bike will eagerly do both with a thoughtless stab of the throttle, so after one or two unintended wheelies you start to be a lot more cognizant of what it is your sitting on and either turn it down or recalibrate your right hand. Those "oshit" moments make you realize the bike has enough power to get you in trouble in one way or another, either by drawing a cops attention or by smoking a pedestrian with potentially lethal consequences if you're an idiot with it. You pretty much have no choice but to self regulate. Also riding like a hooligan tends to drain the pack quite a lot more quickly, which can be good motivation to take her easy as well.

The limit is 32, but I'd be stunned if 42 actually got any negative attention on the street or bike lane. Pedal bikers fly through Vancouver at those speeds everyday. Still though, I like that my controller has the ability to set speed limits per power profile because it's easy to get caught up in the moment on the streets. (I'd be lying if I said that I've never done 20 over through my neighborhood, but I don't make a habit out of it.)

The beauty though is that it's just as happy whirring down mixed use paths in the city at 10-30kmh, or whatever is prudent for the situation. Slow for pedestrians, crawl past at just over their speed, and immediately back to safe cruising speed.

I worry more about what steep hills will do to my SoC than motor heating these days, at least until the 30 degree days of summer. But yeah, temp monitoring is a must to me. I would have cooked this motor a dozen times without it. Don't think I'd feel comfortable running a controller that didn't have the capacity to automatically pull power during overtemp. These things aren't exactly cheap, my attention is spread thin enough, and my luck isn't that good.

 

[HK12K]

2017 Chevy Volt modules from a car with less than 10 miles on it. 21s cells in total. 3 removed without too much trouble unlike the early model packs with the balance tap wires inside the module instead of right on top.

Regarding tires, even my MadAss conversion has fairly small wheels, so I'm really looking forward to the ride of the mid-drive with big diameter wheels and plush suspension, along with enough range to explore paths where all paved mountain roads end.

Sweet! How large is that pack, dimensionally speaking? I'm currently using Turnigys but will eventually desire something... better. Will explore these if the form factor will suit my needs and it doesn't become a threat to life and safety putting it together.

As for wheels I suspect the reduced unsprung weight and better overall weight distribution of the mid, plus the larger wheels, will be a benefit once the trail ends. On road, I'm interested in hearing your thoughts once it's together, especially with your vast experience with big hubs. I recall hearing that on road a larger diameter front wheel starts to become a hindrance after a certain point, centrifugal force and gyroscopic effect and all that. Look forward to hearing what you have to report, comparatively speaking.

 

[markz]

. (Markznotes yeah I know, especially for hills, I've been thinking about that, as I can limit cruising or can I, throttle tends to go more by no other means of limitation then myself

I find self regulation with speed can be a funny thing. When you don't have quite enough power on tap one might tend to keep the throttle mashed to accelerate as quickly as possible and keep up momentum, slowing as infrequently as possible. Like how most pedal bikers tend to ride.

On the other hand though when you have enough on tap to out accelerate cars to the actual posted speed limit you quickly realize that with great power comes great responsibility. For one, the idea of that styrofoam cup of a bike helmet striking a curb at 70kmh makes ya think. But the presumed illegality and knowledge that if you get caught you're boned is ever present. Do 50 in a 50 and you're asking for it. Lift the front tire through an intersection, same. A high powered bike will eagerly do both with a thoughtless stab of the throttle, so after one or two unintended wheelies you start to be a lot more cognizant of what it is your sitting on and either turn it down or recalibrate your right hand. Those "oshit" moments make you realize the bike has enough power to get you in trouble in one way or another, either by drawing a cops attention or by smoking a pedestrian with potentially lethal consequences markz - yeah there was a road lycra human powered a yr or two ago, ran a red and hit an elderly and killed him. He was charged the same as a driver. Dangerous driving causing death. if you're an idiot with it. You pretty much have no choice but to self regulate. Also riding like a hooligan tends to drain the pack quite a lot more quickly, which can be good motivation to take her easy as well. Markz - My riding is tame, 36V probably never got above 35kph let alone 30kph.

The limit is 32, but I'd be stunned if 42 actually got any negative attention on the street or bike lane. Pedal bikers fly through Vancouver at those speeds everyday. Still though, I like that my controller has the ability to set speed limits per power profile because it's easy to get caught up in the moment on the streets. (I'd be lying if I said that I've never done 20 over through my neighborhood, but I don't make a habit out of it.) Yeah that'll be nice. Or have a switch away from the throttle, off is normal, on is limited. Maybe throttle limited somehow, read about it on ES but nothings come out of it. Controller limited via switch be nice, I bought a Cycle Analyst and have never used it, well once. I should sell it, CAv3.

The beauty though is that it's just as happy whirring down mixed use paths in the city at 10-30kmh, or whatever is prudent for the situation. Slow for pedestrians, crawl past at just over their speed, and immediately back to safe cruising speed.
I like to cruise in behind a Lycra, then make comments to passing pedestrians on the pathways. Did that the other day, its quite funny. "Pedaling is for chumps" LOLOLOL I seriously said that yesterday, in Fish Creek Park.

I worry more about what steep hills will do to my SoC than motor heating these days, at least until the 30 degree days of summer. But yeah, temp monitoring is a must to me. YeahI would have cooked this motor a dozen times without it. Don't think I'd feel comfortable running a controller that didn't have the capacity to automatically pull power during overtemp. I must've missed the cont you have, I know you mentioned it so I will read it again. Controller control of temp for the motor is a really good idea for me. I just didnt like the Cycle Analyst I had, it stood out too much.These things aren't exactly cheap Yup gotta learn to not cheap out, cost me plenty., my attention is spread thin enough, and my luck isn't that good. Well I am not miffed about the bbq, coulda been smarter, especially with my mxus 3kw having that temp control controller. I got too set in my lazy ways.

 

[HK12K]

I'm running an Adaptto Max-e. They're now defunct, but if I had to buy a controller tomorrow I'd order a Nucular without hesitation just based on feature-set and ES member reviews. It would keep you from ever roasting another motor, give you the ability to tweak and adjust anything you can think of to suit your needs if you wanted to, including speed limiting... I could go on but I sound like an advertisement. Don't mean to, but from my limited research very little out there comes close all things considered. Not that I'm an authority. Hear good things of ASI as well. Canadian even! I'd still go Nuc, though I imagine there are others that might fit the bill.

Gotta watch for those pedestrians, no matter what you're riding. They're certainly not watching out for themselves, or much of anything else. Still though, best not to hit and kill them.

 

[John in CR]

I find self regulation with speed can be a funny thing. When you don't have quite enough power on tap one might tend to keep the throttle mashed to accelerate as quickly as possible and keep up momentum, slowing as infrequently as possible. Like how most pedal bikers tend to ride.

People without self control should stick to mass transit. No one would buy a car that had performance so lacking that they had to drive around with the pedal to the floor. That would make the slightest uphill grade, puff of wind, or even the battery's SOC slow your vehicle down. It baffles me how anyone can accept that level of performance with their ebike. Just like our van that has been parked for years, I don't even know the top speed of my 3 primary ebikes.

 

[HK12K]

I assume a lot of it comes down to cost and availability. $1000 will buy you a car that can break every speed limit in the country, but that same thousand bucks won't get you going nearly as fast or as far on an ebike. So they make due.

The asinine laws don't help either. 500w max, or they criminalize you. Get real. Might as well stay parked on the couch.

No idea what my bikes top speed is either. Faster than I care to ragdoll down the pavement whilst wearing trackpants and a dixie cup on my head. Also faster accellerating than that gas powered Grom I ended up next to at a light last week, but who's counting?

 

[john61ct]

The asinine laws don't help either. 500w max, or they criminalize you. Get real. Might as well stay parked on the couch.

I think that's just a placeholder for

"call it a bicycle so we don't (yet) need to regulate them like a motorcycle"

Since meantime we can get away with so much flying under the radar, seems a fair deal to me.

As the market developes and the casualties start mounting, I'm sure we'll see sharper regs differentiating between types by power level.

I bet what we have now is better