Geared motor vs gearless scooter acceleration?

Hi all, I have recently acquired a 500w 48v 10inch electric scooter.. speed and range is quite good..

However, a friend of mine has had his scooter (same body) fitted with a geared (the one with the planetary gears thingy), also the same 500w and 48v rating and also 10 inches, however when we tried to drag race his accelerated like it was nobody's business, it was like seeing turbo car vs the non turbo variant..

Both same power rating and body, Is that insane acceleration all to do with the geared vs gearless motor (eg, is this a characteristic of geared motors?) or is it something else?

Cheers!

Controller and battery is exactly the same? I honestly don't know about geared motors, but I do know that startup torque is all about the amperage 8) I've rolled my eyes at recent builds I've seen in-store using 3kW motors paired with batteries/controllers that output only 50 amps peak, and they call it a super scoot...

If your friend's ride is outputting more amps at startup, then that could be it. However, if all variables are held constant except the gearing, then one would assume that's it. You may catch him if you do the shunt mod to your controller

"Insane acceleration" on a 500W scoot geared or not...LOL!!! I pump up to 17,000W (150A at 117V with sag). Geared by small tire size for a top speed of 75mph, and it's close to insane acceleration. I love slaughtering motorcycles. Geared hubbies need not apply.

Noq said:

Controller and battery is exactly the same? I honestly don't know about geared motors, but I do know that startup torque is all about the amperage 8) I've rolled my eyes at recent builds I've seen in-store using 3kW motors paired with batteries/controllers that output only 50 amps peak, and they call it a super scoot...

If your friend's ride is outputting more amps at startup, then that could be it. However, if all variables are held constant except the gearing, then one would assume that's it. You may catch him if you do the shunt mod to your controller

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Hmm I think they are the same.. have to look at his controller.. hmm will google about doing the shunt mod on my controller.. any implications?

Cheers!

John in CR said:

"Insane acceleration" on a 500W scoot geared or not...LOL!!! I pump up to 17,000W (150A at 117V with sag). Geared by small tire size for a top speed of 75mph, and it's close to insane acceleration. I love slaughtering motorcycles. Geared hubbies need not apply.

Click to expand...

Ah.. I should have probably put in "day and night difference".. 150amps? I think you'll wheelie with that much torque! How big is your ride?

job said:

Hmm I think they are the same.. have to look at his controller.. hmm will google about doing the shunt mod on my controller.. any implications?

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Chuckle... yeah a couple. Meltdown, explosion, no warranty, etcetera. You'd basically be allowing it to pull more current than it's rated for by...assuaging...a certain hardware limitation.

Nice topspeed, John. What motor are you on? Sadly I just melted mine and had to downgrade. I'll see your 150/17 and raise you 620/50

"Nice top speed"??? That's my slow motor, a bone stock 14.3kv high efficiency 6 phase MidMonster rated at only 3kw. The key is proper gearing for the load with a 16.5" OD tire, so I get absolute reliability and performance with a motor that never sees 100°C on my 30 mile commute with a mountain to cross. Numbers are meaningless with a melted motor, since it was basically an electric heater.

job said:

John in CR said:

"Insane acceleration" on a 500W scoot geared or not...LOL!!! I pump up to 17,000W (150A at 117V with sag). Geared by small tire size for a top speed of 75mph, and it's close to insane acceleration. I love slaughtering motorcycles. Geared hubbies need not apply.

Click to expand...

Ah.. I should have probably put in "day and night difference".. 150amps? I think you'll wheelie with that much torque! How big is your ride?

Click to expand...

No monos thank goodness or I'd have to turn it down. It's too low and has a longish custom swingarm. Total load with me and backpack is almost 400lbs.

John in CR said:

"Nice top speed"??? That's my slow motor, a bone stock 14.3kv high efficiency 6 phase MidMonster rated at only 3kw. The key is proper gearing for the load with a 16.5" OD tire, so I get absolute reliability and performance with a motor that never sees 100°C on my 30 mile commute with a mountain to cross. Numbers are meaningless with a melted motor, since it was basically an electric heater.

Click to expand...

It melted because I ignorantly painted my coils to combat rust. Very bad move. The 620A peel-out was well before that, and never led to that kind of issue, so I'd say it means something. Months of such abuse, and the coils were still fine. It got my scoot from zero to 60MPH in about 3 seconds. To finally kill it, it took ~15 maximum peel-outs in a row on the daily for 5 months, with ~30 minutes of WOT @ 75MPH/12-15kW mixed in... no chance to cool down... so yeah... and the average peel-out was about 450A, well past its rating. It was a 16" V2 8kW QS hub. I just downgraded to the 5kW version, which I'm driving more conservatively until I can get my hands on higher-rated motor. Not good to put 50kW through an 8kW thing, but she sure took it like a champ, at least till the paint. Having trouble finding much to replace with. Strongest hub I see is a new water-cooled 14kW continuous, 33kW peak-rated 17" by QS. That would be a nice step up, since they apparently dramatically under-rate their products. Figuring I need to move to a water-cooled in-runner to exceed that safely and reliably, but those are not so silent due to the chain (VEEEE!), so I'd rather not, unless it's really the only way. I'm totally with you on burning other vehicles. I love seeing people go "WTF is that thing!" while ripping them to shreds, on a little scooter that doesn't look like it can do it I see you're well acquainted with such antics I'm sure you're a lot smarter than me at this. Would you have any recommendations for high-powered motors? Controller is a Kelly KLS 96501-8080I, 500A peak, 96V max. If required, I'd consider replacing the controller in order to overcome its limitations, if necessary. At 74V nominal, I achieved 75MPH top-speed. Moving from 20S to 24S (100V full-charge, safe enough for the Kelly), would've gotten me up to ~95MPH on the first QS, which is enough for now. It's more that I'm having trouble finding the right motor to move to that can handle all those 30kW+ peel-outs I do. I'm all ears, if you're willing to shed any light on motors that might be up to the task?

When it comes to acceleration even the combination of
1. battery current- we see on our Cycle Analyst
2. load- weight of bike and rider along with grade of the road
3. gearing- Kv of the motor (rpm/volt of the wheel), voltage, and wheel size, and
4. torque constant of the motor (9.549/Kv= Nm per amp)
doesn't tell us the whole story. The motor doesn't see battery current to make torque. It sees phase current, but phase current limits don't tell the whole story. There's how the controller applies the different levels of throttle signal as well the time period it applies to ramp up the current in response to the throttle signal. On top of all that you can have 2 identical controllers and settings, voltages, load, gearing, and Kv, but still get 2 different results with 2 different motors. The difference would be caused by different resistance and inductance of the motors resulting in differences in how the controller responds.

One thing is certain though. Direct drive hubmotors always perform better with smaller wheel diameter, so always use the smallest wheel you can tolerate. That's how despite being fat and living in a mountainous area, I'm still the only one on the forum with a hubmotor driven ebike with a top speed of well over 100mph using settings that are conservative enough for a daily rider with absolute reliability proven by 4 years of use. That's not quite true, since my ventilated cooling approach and high efficiency of the motor also play big roles in me being able to run my SuperV at over 28,000W peak input since early 2013.

Thank you John. I'm once again humbled. I read your post several times. Please forgive my ignorance, I've only been modding for a year. I sure have a lot of reading to do... and it seems there's a podcast too. Feel free to recommend me anything, my thread's quite nearby. Cheers man

Edit: And now I'm torn between smaller wheel for performance, and bigger wheel for traction. I could go big front wheel, or maybe fatter-width back-wheel... you've got the gears in my head turning.... It's very easy for me to skid when cornering quickly, especially if the road is wet, you see.

The podcast is too old...too much learned after that.

The routes to extreme street performance carrying motorcycle loads until we get some new material for stator core or even better a superconductor that doesn't need to be cold to replace the copper losses are:
1. 2 wheel drive with existing motors, obviously the front at lower power, and really big and heavy at the rear.
2. Using motors efficient at high rpm, so they can be smaller for the power required, and running it out of the wheel with a belt to keep it near hubmotor silence.

I see... well, you know you're maxing out when you're waiting for new materials to be developed 8)
The dual-motor option is interesting to me. I remember spitballing with some friends the concept of a dual rear-wheel setup wired to one throttle. You might need to build one of those complicated trapezoidal suspension setups, like the Piaggio MP3 has, so you could take corners. However, as you pointed out earlier John, even with twin motors there might still be power discrepancies between them, and that's might lead to issues when your drivers are physically parallel. By that token, one in front / one in back might be better, although the two motors could only synergise on torque as I see it, as one or the other will surely reach its top-speed first.

QS makes a dual-stator motor, which is a cool option that would ostensibly lead to more startup torque. It seems to be dual controller as there are two sets of phase leads. What a fat swing-arm you'd need. I don't see a lot of info on it, but it seems to perform decently well, even at relatively low wattage, like 3kW on a motorcycle still outstripping strong cars off the line. Imagine a dual 34kW-peak setup That'd be the ticket. This is 13"; there's also a 10". Craziness.

My first hubbie ebike was a front drive, which had no handling problems...some slight differences like the motor pulling bike up straighter accelerating out of curves, so at first I was ending up further left in the lane than planned, but it just took getting accustomed to compensate. My concern with 2wd would oscillations at cruise between which motor is pulling more load. My solution will be to run identical motors with the front in a slightly larger diameter tire. That way the front will always be applying positive torque since it's always trying to go a little faster than the rear. During acceleration the front will have less traction, so it would need lower current levels than the rear.

Other than weight and cost I see no detriments to 2wd....Double the torque potential, double the cooling, better traction and better handling if the front tire comes loose.