First ride: that was weird...

[rocwandrer]

Potentially very cool, but I arrived feeling really confused. I know this is going to sound dumb... I got to work a lot quicker than I intended, and covered in sweat, despite my intention to use the assist partly as a way to reduce the need to change clothes when I arrive. I ended up riding almost the whole way WOT, and pedaling harder than I want to pretty much everywhere. It was a very weird experience, and I'm posting to see if anyone has any insight as to what was going on and how to best address it. I have my own ideas, but I'm new to this, and thought I'd throw it out there to those with more experience.

More details:

The throttle control: My throttle seems to actually not continuously vary the signal voltage (yet to confirm with a multimeter). It has off, low , high, and slightly higher. Low is uselessly slow, the other two settings are nearly the same and basically full throttle. With the effectively on off throttle, I can't get quite the throttle input I want. I tried pulsing the throttle (human PWM style), and it worked pretty well, but it felt very hard on the system so I stopped doing it. For one thing, my Q100 is noisiest right after coming on the throttle.

Uphill: My ride starts with a long gradual uphill (maybe transitioning from a 3% to 6% grade). I ended up pedaling really hard up the hill. I think my subconscious did this because of the payoff of a little more effort giving a lot more speed. I think I can find a balance here, with practice.

Flat: I ended up pedaling really hard on flat. Not sure why I felt compelled to pedal so hard on flat. There was something to it though. When I consciously decided to put in a little less effort, the loss in speed seemed huge, and when autopilot kicked in again, I was pedaling at near max effort again.

Steep downhill: I pedaled moderately, a hair less than I usually do, without throttle.

Gentle downhill: The same as flat, mostly.

I feel like if I could have selected either a very precise, continuously varying throttle position, or a lower amp rate, I would have settled into the expected pedaling effort at a little lower speed.

Anybody have any insight?

 

[neptronix]

You have a super wimpy motor on super tall, super fat tires, so the variation in throttle is not going to do much for you, nor will it feel like there is much variation. It's going to feel like 'on' or 'off'.

Your 'low, middle, high' settings correspond with a speed limit, not a level of power per se.

Why did you chose a q100? I bet all that motor does for ya is help defeat the high resistance of those tires, not much more.
Something like a MAC/BMC motor would be far better.

 

[liveforphysics]

Perhaps a false-positive hall combo.

 

[rocwandrer]

Perhaps a false-positive hall combo.

That does seem to match my symptoms as far as the throttle, but after some weirdness with the hall sensors I decided to run sensor-less this morning.

 

[rocwandrer]

Your 'low, middle, high' settings correspond with a speed limit, not a level of power per se.

I knew that, but I'm starting to understand it too, now. Without getting exactly the right throttle position, the amps are either pegged out or zero. I did test this with the wheel in the air, but not with a speedometer. It seems to have a surge at startup, no speed change for increasing throttle position, and then a surge again. The third surge is more of just a change in the noise, and it doesn't look like the wheel accelerates much.

Why did you chose a q100? I bet all that motor does for ya is help defeat the high resistance of those tires, not much more.
Something like a MAC/BMC motor would be far better.

I chose it for a lot of calculated reasons. I might have been wrong, but I did think it through. Your assessment is just about spot on. I can travel at a little bit faster than summer time road bike speeds over cold pavement while riding the fat bike. I also expect to make forward progress in snow conditions that are unrideable on other bikes, and require too much power for me to ride under my own power on this one. On cold days, when my knees bother me, I can shorten the hills enough to avoid pain. If this works out, I'll probably be sucked in like the rest of you, and have assist on the family bike and/or a good weather commuter as well.

 

[neptronix]

An on-off throttle is usually indicative of a controller that can't handle the speed the motor is going at. Geared motors typically spin at 5 times the rate of DD motors. The problem gets worse the faster you go on controllers that don't do well with geared motors.

You will know this is the case if you hook the same controller up to a DD motor, and there is a good range of power modulation in the throttle.

I experienced this problem with my early cellman controllers ( eb2 ) on my MAC motor. When i upgraded to a EB3 cellman controller, the problem went away entirely. There was a night-day difference.

 

[neptronix]

But i'm talking about a motor that'll put a good percentage of 1500w input power to the ground, and is rated at 500W-1000W.

The difference between my motor and yours is pretty big.

 

[rocwandrer]

An on-off throttle is usually indicative of a controller that can't handle the speed the motor is going at. Geared motors typically spin at 5 times the rate of DD motors. The problem gets worse the faster you go on controllers that don't do well with geared motors.

You will know this is the case if you hook the same controller up to a DD motor, and there is a good range of power modulation in the throttle.

I experienced this problem with my early cellman controllers ( eb2 ) on my MAC motor. When i upgraded to a EB3 cellman controller, the problem went away entirely. There was a night-day difference.

I think in this case, the Ku63 with the Q100 is a fairly well established combo that works tolerably well for a lot of other people, so that's not likely to be my problem.

 

[neptronix]

Perhaps you're more picky than most . I know i am.
Maybe ask some other folks running the same motor + controller combination if they have the same problem.

 

[Ypedal]

you, are the " needs more power " kinda guy i'm sorry to report... well.. your wallet will hurt.. your b rain will say weewww.. it's possible to satisfy the need for speed.

 

[rocwandrer]

you, are the " needs more power " kinda guy i'm sorry to report... well.. your wallet will hurt.. your b rain will say weewww.. it's possible to satisfy the need for speed.

Maybe so, but I've been happily running a 138 HP racecar for 5 years now in a class dominated nationally by a 250 hp model.

To be clear, I'd be happy with a lower average speed, it just didn't seem to work. At a lower speed the motor was doing almost all the work, or none of it. Throttle issues aside, I'm half thinking I need to hack the controller shunt more to have a lower amp limit setting, and half thinking I'd like to keep it as is for hill climbing when my knees hurt.

I'm open for more thoughts, but over the course of the day, it sort of gelled for me that I need to keep using it for a while before I keep making judgments.

 

[melodious]

q100 run @ 36V is a leisurely 15-18mph pace with or without a motor to assist. You have 2 options. Enjoy your leisurely assisted ride, or pedal past it beyond 18mph which is not very hard to do on geared bikes, albeit, with a bit of human sweat involved. When I get on my q85 @ 36V 20" folding bike, I already know in my head what pace I'm setting once I leave the house, and it's definitely not world record pace :wink: , but I do arrive at my destination sweat free.

You have the itch to go faster. So, follow your bliss. That's what I'm doing too. But you need to ditch the small motors and learn how to work with the bigger motors (i.e. 48-72V, geared and direct drive motors, front vs. rear vs. mid motor positions).

 

[bobale]

Flat: I ended up pedaling really hard on flat. Not sure why I felt compelled to pedal so hard on flat.

Don't know why, but happened to me many times. I rode that flat stretch of road (30 miles) quite a few times on regular MTB, and usually I would arrive at destination exhausted, but I've never felt any leg pain or such. On regular MTB I was averaging 12-13mph.

When I did same stretch of road on my e-bike I've arrived much faster but my legs hurted like hell for few hours. My average was 25mph, power consumption was around 6Wh/mi, and it felt like motor is helping me a lot, but it seemed that going fast somehow made me pedal much harder than usual. Mind you, with 48tx14t combo I cycled at higher cadence than usual.

 

[neptronix]

48x14t would make for a super high cadence! get yourself a DNP 7 speed freewheel with a 11T low gear... ya won't have that problem anymore

 

[rocwandrer]

q100 run @ 36V is a leisurely 15-18mph pace with or without a motor to assist. You have 2 options. Enjoy your leisurely assisted ride, or pedal past it beyond 18mph which is not very hard to do on geared bikes, albeit, with a bit of human sweat involved. When I get on my q85 @ 36V 20" folding bike, I already know in my head what pace I'm setting once I leave the house, and it's definitely not world record pace :wink: , but I do arrive at my destination sweat free.

You have the itch to go faster. So, follow your bliss. That's what I'm doing too. But you need to ditch the small motors and learn how to work with the bigger motors (i.e. 48-72V, geared and direct drive motors, front vs. rear vs. mid motor positions).

I'm not in great shape. On my road bike, I can hit 21-23 mph on flat in short bursts, but can't sustain it. The same effort will get not quite to 18 mph on the fat bike with the better rolling tires pumped up decently hard, or an optimistic 15 mph with the current tires/pressures. Rolling resistance also goes up quite a bit in the winter even without the lower pressures I usually end up running. It is a trade off i find worth it for the joy of being able to decide at any point in my commute, if i have time, to head off into the woods on this bike. The bike goes from utterly ridiculous straight to the perfect mix of satisfyingly practical/childish in the woods.

I think I was putting in enough effort to get a little way into the down-slope of the power output curve. I don't know why that might be, though.

 

[rocwandrer]

Flat: I ended up pedaling really hard on flat. Not sure why I felt compelled to pedal so hard on flat.

Don't know why, but happened to me many times. I rode that flat stretch of road (30 miles) quite a few times on regular MTB, and usually I would arrive at destination exhausted, but I've never felt any leg pain or such. On regular MTB I was averaging 12-13mph.

When I did same stretch of road on my e-bike I've arrived much faster but my legs hurted like hell for few hours. My average was 25mph, power consumption was around 6Wh/mi, and it felt like motor is helping me a lot, but it seemed that going fast somehow made me pedal much harder than usual. Mind you, with 48tx14t combo I cycled at higher cadence than usual.

This is what I'm talking about. I'm remembering something like this last winter... When I run out of gearing on my single speed studded tire ice bike, I tend to pedal up to an unsustainable effort level, coast, and then repeat. I think I did that because it is uncomfortable to pedal at high cadence and low effort.

So if the same thing was happening, once i got above the peak power output rpm of the motor assist, I'd quickly encounter a very steep increase in effort for very little increase in cadence, the sweet spot of enough effort for the high cadence. I think this is it; the reason for the subconscious excess effort!

 

[d8veh]

Do you have the high or low speed version of this motor (201 rpm or 328 rpm)? It nakes a big difference to how it behaves. I found that ther 201 rpm one performs very well at 17amps (1/3 of the controller shunt soldered) and 12S lipos (about 48v). With the 328 rpm one which I ran at 15 amps and 36v, the throttle was like an on/off switch and it drew maximum current nearly all the time, which caused the controller to get rather hot.

 

[rocwandrer]

Do you have the high or low speed version of this motor (201 rpm or 328 rpm)? It nakes a big difference to how it behaves. I found that ther 201 rpm one performs very well at 17amps (1/3 of the controller shunt soldered) and 12S lipos (about 48v). With the 328 rpm one which I ran at 15 amps and 36v, the throttle was like an on/off switch and it drew maximum current nearly all the time, which caused the controller to get rather hot.

I have the 201 rpm version. I have also removed a little bit of material off the shunt. The motor whines pretty badly at low rpm. I wonder if I am using it below the temperature the grease on the planetary reduction is good for...?

Another update, the throttle now works intermittently (I am rubbish at electrical hands on work, and I think that is the reason...) but does seem to be behaving in a closer to continuously variable sort of way. It could be internal to the throttle too, as the return spring seems to be hanging up worse and worse, sort of like something is broken inside and binding on the spring.