Puma/hub motors Off Road?

Well after my most successful EV project being my first Hub powered electric bike, I am very impressed with the hub motors (2 previous, were scooter style). My current setup is great for on road riding since I have around a 30mph top speed, cruiser tires, no suspension, and a rear bag carrying batteries. I see no end in sight for this bike but desire my original purpose for getting into electric vehicles: DIRT! What I want is high torque, around 18 mph top, full suspension, nice downhill tires, wheelie popping ability.

To achieve this I am looking into the puma motor mounted in a 20in wheel. After getting to ride xyster puma power bike I was impressed with the torque for the size and weight of the motor. I plan to run my setup on 2s dewalt packs so, 66v nominal and 3p. I am really interested in this new puma version with metal gears and heavier wiring. I am hoping to run around 35 - 40 amps, so over 2500 watts. Can the motor handle this kind of power or will it burn up?


My second question is: will these motors or any hub motors be able to handle harsh off road conditions (Big bumps, dirt, sharp hits). I think of what I ride over with my mountain bike and picture the magnets falling off, windings shorting, ect. Even with full suspension it doesn't help what the motor has to deal with, it only helps me keep the wheels on the ground and give me a more controllable ride.

at that level - thermal management would be a must - ie have a temp sensor for the motor.

2900w + on the 408 i've got is fairly close to the limits (it heats up nicely after a long hill at slow speed).

2500w on the puma would be similar. this is why the new puma controller throttles amps back to 20a at 72v. its a lot lighter motor, which means it doesn't have the thermal mass to disipate heat as easily.

I must not be reading this correctly, but Xyster's puma ???? huh ? :?

Ypedal said:

I must not be reading this correctly, but Xyster's puma ???? huh ? :?

Click to expand...

As ypedal said:
xyster has an X5 bike not a puma.

He was probably thinking of Matag's bike.

Anyway, I'd like to do the same thing (someday), since there are lots of dirt trails around my house. Some of them are very steep. I'd also want a very stealthy setup, since I suspect the local officials would frown upon a "motorized vehicle".

Other than Knoxie, I don't think anyone has enough miles on a Puma to know the long term reliability, and the models seem to keep changing. I don't even know where you could get a Puma in the states.

The other possible way to go would be some kind of BB drive, so you could gear down for hills. The freewheel setup needed for the cranks is a challenge, as is motor mounting. Not as stealty either.

the new pumas are rated at 500w but when you consider that the old 250w versions are capable of running 1500w no problem, i suspect that the 500w could run 2500w without too much of a problem.
Early versions like i have have had issues at higher power - the nylon gears wear and the drive gear suffered slippage but now that these problems are dissapearing thanks to guys like knoxie and jozzers testing i think we will see the new motor as being very capable and if it delivers as expected it will be one hell of a motor.
As knoxie mentioned mark is getting factory made puma's with all high power mods done at source so i would hold on and get one of those, although obviously i am biased
I can tell you that at 36v in a 20" wheel my top speed on flat road is exactly 18mph - that was running 36v@35a and i have to say it is still wayyyyy torquey.
I have ridden mine in the forest and i have bashed it around a fair bit and i have to say that it's stood up fairly well to my tree root thumping and slamming about.
As fetchter rightly sais it's early days and i dont have enough miles to give a well rounded review but for me the bottom line is this...
.....
the x5 is 25lbs.
my puma and 2 x 36v 15ah lipo's is 28lbs.

if you hold on just a few more weeks i will be able to show you on video what the old puma can do at 72v in a full suss mtb.
i would hang fire and then make a decision in a few weeks once knoxie has finished testing the new controllers and i'm able to run mine at higher power.



cheers


D

Wow that would be great get some uploaded when you can. And you guys are correct it is Maytag, my bad. You guy answer most of the questions but what about the crazy vibrations these things see at off road, can they handle it? Has anyone had a magnet fall off?

fechter,

Using a normal external motor is my other ideal option but like you said mounting is an issue. I guess I could tap into the front chain rings but I think I would need a additional reduction at the motor like the Cyclone kits. But that is why I also started the saturation thread of BL motors. I might trying using a large outrunner hobby motor but that is only if the hub motors don't work out.

http://video.google.ca/videoplay?docid=-4749862029616241264&q=72v+off+road&total=1&start=0&num=10&so=0&type=search&plindex=0

This is a video i made a long time ago..

I've beaten this motor pretty hard, ( clyte 406/409 ), and it keeps on rolling.... 8)

Depends on your version of " Off-Road " but nature trails and general gravel roads should be fine..

Happy to report the new controller made the grade, Marks gone ahead and ordered 50 motors/trollers. They should be here for christmas

I've got several hundred miles on one of the prototype puma's, and though there have been some changes since to the final version, they were all changes for the better. Personally I have no doubt about long term reliability. It may or may not be nesacary for me to replace the gears in the future, but I'm certain this will be job for after thousands of miles not hundreds. Most of my mileage on this motor was done at 2500watts or so, most rercent configuration is 66v@45A. The motor doesn't get hot at all, although I can imagine that in a hot country whilst climbing a volcano it may be an issue! Mostly the torque is high enough that you get to speed very quickly though, and power consumption drops off.

One of these days i'll try an X5 to compare (I'm scared of the weight!!), but the puma definitly will perform offroad much better than a crystalyte 408.

I have a Currie USPD planetary gear reducer that will fit a Kollmorgen. If you toss the internal controller, you could replace it with a thin aluminum cover, which will make the motor about 3/4" thinner. Combined with the USPD planetary, it would probably fit between crank arms (barely). Then it could be mounted right above the front sprocket.

The RC motors and gearboxes are very noisy and sound like an electric drill. I don't think they would hold up over the long haul either. The Currie USPD planetaries are all metal gears and hold up pretty well.

a Dual-Koll would be pretty cool !!!!!

side-by-side on a big plage maybe ?

Kind of like the pic below.

Or you could fit dual sprockets on to one motor if that makes the chain run easier. There are off the shelf sprockets that should allow this with no work.

The BMC motors in that picture have the same hole spacing as a Kollmorgen

Great now I'm looking at getting TWO brushless motor controller!!! This is all just planning. If I did use the Kollmorgen I plan on getting another Cycle analyst so I build the whole set with the ability to limit current at preset levels. I keep you guys up to date.

Duals should go pretty good at 48v. At 35 amps each thats over 3000 watts going to the motors. And they've proven they can handle 1500w each. As you know cost isn't really an issue doing multiples with these. Over 48 volt Knoxie says the Koll magnets fly apart... I think duals would be the perfect alternate to going 60 or 72 volts and having to worry about that.

Okay well I have an opportunity to buy a BMC 1500w motor for around $250 . Now seeing how it is they rate these things, that is continuous so I'm hoping to do somewhere around 2500w peak. It would be running at 33v like 80 amps. The motor has a 7/8in shaft and is kinda heavy 12lbs. But I can't find any specs anywhere, I think I'm going to do you what do you guys think?

That's a honker! Tim Obrien reports very good results with those. They seem to be very efficient. Just get the gearing right.

Considering that I can run up to 5kw with my "600w" motor, I don't think you'll have to worry about cooking that one.

Yo

Yes Given an option I would go for the BMC the kol motors are great but get them too hot or run them too high the rotor magnets crack and break of the rotor body (this is not good!) and then you have a heavy ride back home.

Id go for a blown BMC rip out the controller and run that, Puma with all steel gears and a welded rotor would rock and roll off road, would be worth fitting a button stat inside the motor or an NTC thermistor to throttle the controller back on rising temp. I have been running 1.4KW for about a year now in a Puma, the gears have gotten a bit worn now, that said it was a first generation motor, however it will be getting some steel gears soon.

2KW with steel gears I see being no problem at all, thermal cutout will help keep things from getting silly.

Jozzers rig is a bit more extreme than mine, a good testbed for the Puma in the coming months.

Richard I think you may be getting something via airmail that may tickle your fancy! ha ha

Knoxie