Astro 3220 / NuVinci build

[MattyCiii]

Ten months after my last post to this thread, I have experience to support some thoughts & assumptions.

I have 2 bikes using Astroflight motors (3210 and 3220). Both drive NuVinci N360s through the left side, meaning *not* through the gears. Both builds are linked in my sig.

The Norco A-Line has a really low granny gear. It's a heavy bike with great rotational inertia in the wheels. When I pedal, I feel the slushiness in the N360. It's strange! I don't feel the same slushiness in the folding bike, but that bike is lighter, not geared as low, and has lighter wheels (less rotational inertia).

Both bikes have both an insane amount of torque, starting from zero RPM, and a great high end (30+ MPH each). I don't get a commission on sales of RC motors, drives or belts - and I hope I don't come across as too much of a zealot - but with two vastly different e-bikes, the commonality is using an N360 as a pedal-only transmission, and sending e-power to the wheel separately.

Perhaps there's something to be gained in running power through the NuVinci, but in my experience one does not need to. A transmission's purpose is to get both good low end torque and high end speed out of a power plant. IMHO, a 3220 can give both with no (variable) transmission, just a 20:1 (ish) gear down) and it gives both insane torque and bountiful speed (the 3210 does the same, albeit on a bike that's about 50 lbs lighter).

 

[Green Machine]

I have tried an air cooled 3210 running 4000 watts through a nuvinci through the gears.

Personally i think the astro is much better through the gears then single speed...i think both the 3210 and 3220 are too delicate to be run single speed in any hilly or off road terrain. I smoked 3 3220's so far single speed in my testing and will now only run them through the gears.

I feel the nuvinci at 4000 watts was noticiabley inefficient.

Also i blew out the freewheel built into the nuvinci while shifting from gear to gear in high power. The free wheel snapped when applying power after shifting int the higher gear.

Fallbrook replaced the freewheel no problem. If i had to pay it would have cost 25 dollars.

I am now running a Rohloff and so far no problems.

 

[rscamp]

I have tried an air cooled 3210 running 4000 watts through a nuvinci through the gears...

Holy crap! What voltage and number of turns? In most arrangements running continuously at that power level that motor would generate a ton of heat. It wouldn't help that it would be way past it's peak efficiency at that power level. It can be done with enough cooling, but it would really be the wrong size motor for the job...

 

[recumpence]

I do think there were some issues with Astro motors in that particular timeframe that Green smoked his. Right at that point I saw a few people smoke motors. However, before then and since then they are lasting. Also, this occurred in competition applications. Green smoked his climbing Pike's Peak and others smoked motors racing. A testament as to the quality of the new style Astro motors is the fact that FFR won Pike's Peak (first and second places) waaayy ahead of the other competitors and that without any heat problems.

That being said, all RC motors "Have heat problems" in the respect that they are all small and, therefore, have very low thermal mass. Lets face it, we are expecting a 2 to 4 pound motor to do what would have only been expected of a 25 to 30 pound hub motor a mere 4 years ago.

I am glad guys like Green have stuck with it to work out what is best for their particular use. That is what drives technology forward.

Matt

 

[Green Machine]

Yeah i agree with Matt there might be a difference in motors in the last few years. All the motors i smoked were older astros, and the new guys at Astro have seemed to address the overheating issue.

I am running a 10 turn air cooled 3210 ran in delta and it is flawless at 4000 watts as long as the air cooling fan is turned on and it is run through the gears.

This is one of the new 3210's. Actually on the same bike i smoked an older 3210 10 turn wye non air cooled...

The new motor has been flawless and has really upped my confidence in rc technology. It has air cooling holes and a fan constantly blowing so it is not sealed which is a definite drawback.

I noticed one time i did not plug in the fan and smelled the familiar something is smoking inside the motor smell. I am pretty sure if i ran 4000 watts to the motor without air cooling i would smoke it. If i were running a 3220 with the same wattage non air cooled i think i would be fine.

The motor has an extremely tight power band compared to a hub motor, and the gears really help.

I really liked the nuvinci although i am not sure if it will hold up to 4000 watts long if you are not careful during shifting. The Rohloff is just amazing but spendy. I think it is well worth it given it is one of those things you will own a lifetime and get serious use out of it.

This is the 3rd electric bike my rohloff has been on.

 

[Green Machine]

Yeah i agree with Matt there might be a difference in motors in the last few years. All the motors i smoked were older astros, and the new guys at Astro have seemed to address the overheating issue.

I am running a 10 turn air cooled 3210 ran in delta at 4000 watts continuous as long as the air cooling fan is turned on and it is run through the gears. I hit 46mph and can climb anything. My top speed with the bike optimized (tire pressure, fresh charge) is over 50mph. Top speed in low gear is 12mph...and omg try to stop me. My confidence is growing in my set up daily. Every morning i am doing a strenuous test ride.

This is one of the new 3210's. Actually on the same bike i smoked an older 3210 10 turn wye non air cooled while running up big off road hill...

The new motor has been flawless and has really upped my confidence in rc technology. It has air cooling holes and a fan constantly blowing so it is not sealed which is a definite drawback. Riding this thing up san francisco hills off road in low gear is definately an acid test....I have smoked many motors here.

I noticed one time i did not plug in the air cooling fan on this new motor and smelled the familiar something is smoking inside the motor smell. I am pretty sure if i ran 4000 watts to the motor without air cooling i would smoke it. If i were running a 3220 with the same wattage non air cooled i think i would be fine.

The motor has an extremely tight power band compared to a hub motor, and the gears really help because of this. After running through the gears and learning this motor this way i would never go back to single speed for my use. Maybe if i lived in the flat lands and did not ride off road. By the way riding off road in low gear is a great thrill.

I really liked the nuvinci although i am not sure if it will hold up to 4000 watts long if you are not careful during shifting. The Rohloff is just amazing but spendy. I think it is well worth it given it is one of those things you will own a lifetime and get serious use out of it. My rohloff will always be one of my favorite possessions. This is the 3rd electric bike my rohloff has been on.

I dont have any serious numbers yet but there seems to be a big difference between the nuvinc n360 and the Rohloff in terms of efficiency when it comes to high power. I am guessing as high as 30 percent. The nuvinci feels like a cheap toy compared to the rohloff. I have no hopes of my nuvinci lasting a lifetime.

The rohloff has the added benefit that its nearly impossible to over torque and break since it has nylon pins that will break free before doing any damage to the innards. Its a 60 dollar job for me to repair the rohloff from the local service center if those pins do happen to break loose.

 

[rscamp]

Cool. It is great that so much cooling can be applied. No problem. You guys keep on pushing the envelope so us regular guys can benefit from greater reliability.

But there's still no free lunch due to the efficiency difference. My guesstimate is there is probably at least 450W of waste heat with the 3210 vs 350W or so with the 3220 because of the different efficiencies at a 4000W power level. No?

 

[MattyCiii]

But there's still no free lunch due to the efficiency difference. My guesstimate is there is probably at least 450W of waste heat with the 3210 vs 350W or so with the 3220 because of the different efficiencies at a 4000W power level. No?

The 3210 and 3220 each have a claimed efficiency of 93% (3210, 3220. I've had each of these motors - geared to their respective sweet spots - launch me up the same big hill. Both peak at about 3KW on the worst part of the hill. Both are only a little warm when I get to the top. Not very scientific I know...

 

[brgnsnfr]

isn't a derailleur system considered to have around 3% power loss
it wouldn't make sense for nuvinci to bring out an igh with power loss compared to derailieur, greater than 5%
clean-mobile an edrive manufacturer in germany that designed an edrive postal delivery cart that could haul weight at 20mph
'was very confident' using the nuvinci cvt because it can handle 'a lot of torque'
that's as much as they would say because nuvinci won't warrantee beyond 250w and won't quote a max torque like rohloff will,
other than to say they have tested it 'well beyond 250w with no failure'
i would have confidence using it up to 4x the warranteed rating, 1000w and i intend to on my project
the worst that can happen is $400 down the drain, hopefully that's not too much of a hardship and you replace it with a rohloff