Astro vs Revolt engines

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nowholeself   100 mW

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Astro vs Revolt engines

Post by nowholeself » Sep 28 2019 4:53pm

I've just completed a BBSHD build with a good number of engine, wiring, and controller mods. I like it. But I have three issues. First, I can't run full throttle as long as I'd like without generating an alarming amount of engine heat. Second, I'd like the engine to fit into the triangle rather than hang below the bike, for obvious reasons. Third, the BBSHD is needlessly heavy. Like, it's just bizarre to me that Bafang didn't make a little more effort to shed weight in some obvious places.

So, my plan is to make my own casing and drivetrain design. I'm currently looking at two engines that fall within the performance/weight range I'd like: the Astro 3220, and the Revolt RV-120Sh. In terms of performance and weight, the Astro looks superior. But I've read it heats up easily. Also, I'm unfamiliar with the controller technology. Apparently, you can easily blow these things with a voltage spike. Can anyone tell me whether or not my concerns about the Astro are warranted? Specifically, is the heat generated by the Astro engine something to worry about? Or can it run hot all day long without issues? And is using a sine-wave controller like the ASI BAC series possible and preferable? And how do the Revolt engines perform in comparison? Thanks in advance to anyone who can offer advice. This forum was so helpful during my first build.

aCeMadMod   1 kW

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Re: Astro vs Revolt engines

Post by aCeMadMod » Sep 28 2019 5:55pm

Hi it used be inrunner vz outruner. In this space.

Astro vs Revolt engines.

I crazy not willing to kill motors to find out who is best .

Just what we know Astro is best.. In heat

Unless you work for nasa. Or some thing

When you start talk about $4000 a motor
few play this this ..

I look forward to your info good luck

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Re: Astro vs Revolt engines

Post by flat tire » Sep 28 2019 7:12pm

I heard some bad things about revolt in another thread after noting that their price / performance looked decent.

Astro is reliable and makes less heat than most motors due to high efficiency but it needs to spin at high RPM...all astro models.

CYC X1 pro is a recent mid drive with .2mm lams that appears to be on par with astro efficiency wise.

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Re: Astro vs Revolt engines

Post by Grantmac » Sep 28 2019 9:18pm

+1 on the CYC.

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nowholeself   100 mW

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Re: Astro vs Revolt engines

Post by nowholeself » Sep 28 2019 9:22pm

I'm averse to the garish planetary gears. But I might reconsider. What's the noise level like? After I put ceramic hybrid bearings on the bbshd it became inaudible beneath the road noise.

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Re: Astro vs Revolt engines

Post by aCeMadMod » Sep 28 2019 10:00pm

Ask me . I use it all

I would stay modding mini cyclone.
Don" t wates your money Cirramic bearings i did . Get ntn

One user es here made upgrade gears . For mini cyclone motors

Just need turn down 0.3 mm to fit

It work like bigger bother c3000 motor other wise get c4800 if you want power steel gears

I can tell you not hear me when rideing .

Good luck

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Re: Astro vs Revolt engines

Post by StinkyGoalieGuy » Sep 30 2019 7:14pm

nowholeself wrote:
Sep 28 2019 4:53pm
First, I can't run full throttle as long as I'd like without generating an alarming amount of engine heat. Second, I'd like the engine to fit into the triangle rather than hang below the bike, for obvious reasons. Third, the BBSHD is needlessly heavy. Like, it's just bizarre to me that Bafang didn't make a little more effort to shed weight in some obvious places.
What volts/amps and gearing are you running at? Have you tried increasing the RPMs, and then gearing it down? I'm using an external controller - PhaseRunner at 82.5volts nominal. I peak at 2400 watts. I haven't too many issues. All of them have been mechanical, like dropped chains and destroyed rear hubs. And my commute involves climbing a 32% dirt grade. Mind you my entire commute is only about 5 miles each way.

The motor hanging low, can't do anything about that, besides getting a different frame

Regarding the weight, it's not bad considering you are getting a near silent gear box along with a motor that can handle 2400 watts. Others have run it at 3000 watts.

Sure, you could do better with an Astro, but you have to add the weight of the drive train as well. And they also make a high pitched whine. Not sure anyone has gotten it to be as quiet as a BBHD.

It all depends on what your priorities are.

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Re: Astro vs Revolt engines

Post by nowholeself » Sep 30 2019 8:43pm

Thanks for the response. Just to be clear, getting an Astro would be an additional build on a custom titanium frame. Because I'm a crazy person. :D

The high-pitched whine is a dealbreaker for me. Do y'all reckon putting an Astro 3220 inside an aluminum second skin/heat sink would kill the noise? Has anyone tried this? All the designs I've seen keep it out in the open.

As for my heat issue, that may have been due to the high 80's temps here in SoCal. Now that the weather has cooled down everything seems fine. For future reference, though, my setup on the BBSHD is a 60v ASI BAC 800. Gearing is 40/16 with 24" wheels. It's a lightweight cruiser bmx. So much fun. The pack is high drain Molicel P42a 21700 14s2p. 45amps contiuous. No bms. I balance charge.

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Re: Astro vs Revolt engines

Post by StinkyGoalieGuy » Sep 30 2019 10:05pm

I would love to see someone successfully do some type of noise reduction enclosure on an Astro build. Then I could copy their design. My Astro build has been sitting, collecting dust since I have been playing with my BBSHD. I want go back to it and do a noise enclosure as well, but just no time. The problem with the Astros 32xx is you either have to go big amps or a multistage gear reduction at higher volts since the RPMs are so high. At least I do for my use case where I need to climb real steep hills, starting from a standstill. Or you have to add hall sensors. The Tangent drive is able to get a high reduction in a compact setup with the trade off being noise.

For reference, I'm running 82 volts, with a 30T at the BBSHD to a 39T on the rear cassette on a 26" wheel - so yes, very little stress on the motor and tons of torque. I top out around 25MPH which is plenty fast on my trail commute. And like I said, the critical part for me is being able to get up that 32% grade.

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nowholeself   100 mW

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Re: Astro vs Revolt engines

Post by nowholeself » Sep 30 2019 10:18pm

StinkyGoalieGuy wrote:
Sep 30 2019 10:05pm
I would love to see someone successfully do some type of noise reduction enclosure on an Astro build. Then I could copy their design. My Astro build has been sitting, collecting dust since I have been playing with my BBSHD. I want go back to it and do a noise enclosure as well, but just no time. The problem with the Astros 32xx is you either have to go big amps or a multistage gear reduction at higher volts since the RPMs are so high. At least I do for my use case where I need to climb real steep hills, starting from a standstill. Or you have to add hall sensors. The Tangent drive is able to get a high reduction in a compact setup with the trade off being noise.

For reference, I'm running 82 volts, with a 30T at the BBSHD to a 39T on the rear cassette on a 26" wheel - so yes, very little stress on the motor and tons of torque. I top out around 25MPH which is plenty fast on my trail commute. And like I said, the critical part for me is being able to get up that 32% grade.
What sort of "big amps" are we talking here? One of the reasons I've been able to keep my current build so light (under 40lbs!) is that the 14s2p 21700 pack is sufficient. I definitely put a strain on it - it's very warm after I hot rod. But it does the trick and is only 4lbs. If I have to substantially increase battery size, then the weight savings of any Astro are negligible in the end.

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Re: Astro vs Revolt engines

Post by nowholeself » Sep 30 2019 10:22pm

I'll note that, as you've probably guessed, I don't need to go that far. In any case, I'd like whatever engine I build to not need a huge battery to blast down the street.

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Re: Astro vs Revolt engines

Post by flat tire » Sep 30 2019 11:19pm

If you want a quiet motor start with something that doesn't need to spin 8000+ RPM to be efficient (astro). High ratio reductions are inherently loud even in the best case. This means you will need a heavier motor, but there is a price to pay for silence. If you did want to silence a given motor, thermal issues aside, you would want to use a sound damping material like dynamat not aluminum.

Bear in mind that direct drive hub motors win the quiet contest hands down. Remove the bike chain and the only noise is your tires. Very, very quiet.

Re battery size, you can use high C rate and still have tons of power out of a small battery. So small battery is always an option, you will just have small range other things equal.

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Re: Astro vs Revolt engines

Post by StinkyGoalieGuy » Oct 01 2019 1:33am

nowholeself wrote:
Sep 30 2019 10:18pm

What sort of "big amps" are we talking here?
Well, if we take your current setup of 60V, 45 amps continuous, you are looking at 2700 watts.

For the Astro motors, most people are running the Castle Creations HV controllers like the Talon, which only go up to 50.4 volts. So to get your equivalent 2700 watts, you are looking at 53 Amps continuous. I guess it's not that big of a difference from what you are already doing if you are ok with 2700 watts.

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Re: Astro vs Revolt engines

Post by goatman » Feb 04 2020 9:10pm

nowholeself wrote:
Sep 30 2019 10:22pm
I'll note that, as you've probably guessed, I don't need to go that far. In any case, I'd like whatever engine I build to not need a huge battery to blast down the street.
how are the molicel p42a holding up? you must have quite a few cycles on them by now

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Re: Astro vs Revolt engines

Post by nowholeself » Feb 04 2020 9:16pm

goatman wrote:
Feb 04 2020 9:10pm
nowholeself wrote:
Sep 30 2019 10:22pm
I'll note that, as you've probably guessed, I don't need to go that far. In any case, I'd like whatever engine I build to not need a huge battery to blast down the street.
how are the molicel p42a holding up? you must have quite a few cycles on them by now
They're holding up reasonably well. The pack still gives me fairly good performance in terms of speed/acceleration in comparison to when it was new. The most noticeable difference is drain time. I'd estimate I only get about 5 hotrod miles before it's time to charge. Let me know if there are any tests you'd like me to run. I have a balance charger with a good deal of options.

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Re: Astro vs Revolt engines

Post by goatman » Feb 04 2020 9:37pm

nowholeself wrote:
Feb 04 2020 9:16pm
goatman wrote:
Feb 04 2020 9:10pm
nowholeself wrote:
Sep 30 2019 10:22pm
I'll note that, as you've probably guessed, I don't need to go that far. In any case, I'd like whatever engine I build to not need a huge battery to blast down the street.
how are the molicel p42a holding up? you must have quite a few cycles on them by now
They're holding up reasonably well. The pack still gives me fairly good performance in terms of speed/acceleration in comparison to when it was new. The most noticeable difference is drain time. I'd estimate I only get about 5 hotrod miles before it's time to charge. Let me know if there are any tests you'd like me to run. I have a balance charger with a good deal of options.
5 hotrod miles at 45amps from an 8ah pack. I wonder if your pack is down to 5ah.

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Re: Astro vs Revolt engines

Post by macribs » Feb 08 2020 9:16am

nowholeself wrote:
Sep 30 2019 8:43pm
Thanks for the response. Just to be clear, getting an Astro would be an additional build on a custom titanium frame. Because I'm a crazy person. :D

The high-pitched whine is a dealbreaker for me. Do y'all reckon putting an Astro 3220 inside an aluminum second skin/heat sink would kill the noise? Has anyone tried this? All the designs I've seen keep it out in the open.

As for my heat issue, that may have been due to the high 80's temps here in SoCal. Now that the weather has cooled down everything seems fine. For future reference, though, my setup on the BBSHD is a 60v ASI BAC 800. Gearing is 40/16 with 24" wheels. It's a lightweight cruiser bmx. So much fun. The pack is high drain Molicel P42a 21700 14s2p. 45amps contiuous. No bms. I balance charge.
Unless you know for sure that people have found a way to improve the Revolt's or there have been drastic improvements in design and production for the Revolt I would just forget about them. I can't remember anyone here that was pleased with their Revolt. Tbh the price is likely the only thing they got going for them motors. But you likely end up like many others on the forum, a rather expensive piece of motor sitting in a shelf or boxed into storage. To be fair, I have not been really active here the past year or two, so things might have changed over at Revolt, but I would not take Revolt's word for that. I would see live proof of a well working Revolt powered ebike before committing.


If you buy the astro 3220 from our forum member Matt I think he does a mod to the astros. He puts on cooling fan blades or something like that. And astro uses high temperature magnets and wiring so with the correct gearing I wouldn't worry about heat in the astro. Matt pushes like 12-14 kw peak from those astro 3220 motors iirc. Surely only for a few second bursts but you accelerate so quickly a few seconds is all it takes :D

If you search the forum davinci drive you will find the man behind the drive and maybe some inspiration if you like to take on the task of added cooling. Look at how to moto mount clutches the outside can. The pic to the left is the latest verison iirc.

Image

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