Back In A Currie: 06 Mongoose Review

[Instant Karma]

To answer your question "Is Currie being cheap?" if they welded the
kickstand and controller to the bike and use cheap brushed motors, i would say the answer is yes. They probably figure most buyers will tire of the bike in a short time before blowing the motor out before warranty expires and even if they have to honor the warranty a cheap $30 wholesale motor is not much of a problem to replace.
http://www.evdeals.com can answer your question with regard to the USPD systems, sprockets etc.
I think the future of ebikes will be front crank driven systems like the Cyclone or Stokemonkey, along with pedaling and using gears you can go a long way on a little. Simplest is stokemonkey they simply use a hub motor for quietness and built in gear reduction to turn the crank on left side of bike, but there's no freewheeling, you have to keep pedaling along with the motor and most of the lazy asses who ride e bikes dont want any of that.

 

[Lowell]

To answer your question "Is Currie being cheap?"

Simplest is stokemonkey they simply use a hub motor for quietness and built in gear reduction to turn the crank on left side of bike, but there's no freewheeling, you have to keep pedaling along with the motor and most of the lazy asses who ride e bikes dont want any of that.

Can't really complain about cheap build quality when it only costs $300.

As for 'most of the lazy asses' that's pretty insulting. People will ride ebikes for many reasons. A lot of people don't want to arrive at work all sweaty for example and an ebike allows them to ride where they otherwise wouldn't normally. Before I electrified my Rocky Mountain, it would take me 1hr20m to pedal to work, and now I can make the trip in just 32min.

http://endless-sphere.com/forums/viewtopic.php?t=1148

 

[Instant Karma]

If you're pedaling along with a motor which is doing most of the work it's unlikely you'll get too sweaty unless you have malaria or something.
Lazy asses is mainly for those who use huge hub motors with lots of batteries and basically useless pedals to masquerade as an e bike when it's actually an e scooter (old or handicapped people not included).

 

[knoxie]

Hi

Theres nothing more lazy than jumping in an SUV and putting your foot down, there are very very few out and out Electric motorbike builds around and also many people that have them also ride less powerful bikes as well whilst peddling.

I do 5,000 miles on my bike, it sure is very powerful and can do 40mph If I want to but I choose not to, Just because a bike can go fast doesn't mean people are lazy assess for owning them? In fact I ride 20 miles most weekends not even touching the motor as a workout and then use the last 10 miles on motor as a nice cool down.

I personally think a high power assist on an e-bike is a life saver, fast acceleration and being able to match the top speed in traffic which is typically 20mph or less now in most towns and city's is safer, in fact to prove my point there was some scary footage today of a Chinese man run over by a bus! he came away unscathed but it was horrific to watch, had he had a powerful e-bike he would not have been passed by the bus.

Lazy asses drive cars, I don't own or drive a car I actually cycle with no motor 50% of the time, I am fitter and 40lbs lighter since i dropped the car, I own a very high power bike? I am a lazy ass !!

:lol:

Knoxie

 

[fechter]

I'm a lazy ass, I admit it. I hate pedaling. It's like work.
I don't have a problem with that at all.

 

[Malcolm]

I personally think a high power assist on an e-bike is a life saver

I'm with you there Knoxie, ye lazy arsed southern git
Without dedicated bike lanes you need something to even the stakes, and a feeble motor that can't take you past 15mph isn't going to do it.

 

[Mathurin]

To ride a bicycle, you have to take the time to learn to ride it. Being slower then the other vehicles most of the time is part of what makes a bicycle, it's not for nothing ebikes are limited to speeds slower then motor vehicles pretty much everywhere... Don't kid yourself...

 

[xyster]

This morning I worked on adding forced air cooling to my Currie, "Mo" (as in Mo' Mongoose ).

I had already chopped the motor wires to replace the rear wheel, rejoining with part of a nylon Euro-style terminal strip.
http://www.allelectronics.com/cgi-bin/category/755200/Eurostyle.html

I removed the cover; drilled a 5/8" hole for a PVC elbow; replaced the brushes which always pop-out, securing them with folded-over electrical tape; then replaced the cover, pulled the tape, and secured the elbow with epoxy -- making sure the elbow was pointed down a little to prevent water from entering before I attach a hose and a 24v blower.

Next, I'll join to the 90-degree elbow a 22.5-degree elbow to see if just the wind can force enough air in to preclude the need for a blower.

 

[TylerDurden]

Hi Xyster,

Great pix.

You might consider drilling the case between the magnets. The cover holes will cool the brushes, but not the windings.

Then you could pressurize the case openings and the forced air would exit out the cover, taking the brush dust with it.

 

[fechter]

On my Zappy motor, I drilled a ring of 1/2" holes in the sides of the brush end cover plate. This way I avoided drilling out the brush holder plate.

The shaft end of the motor has the exhaust holes, so the air is forced over the windings.

I used a plastic cup as an intake plenum to supply air to all the holes from the blower hose.

I think you need to make the holes bigger. You won't get much air through 1/4" holes.

If you can't make vent holes on the shaft side due to the gearbox, then you want to try and get as much circulation as possible to flow past the windings. I wouldn't recommend drilling between the magnets since the metal there is needed to carry the magnetic flux.

Here's some crappy pics:

 

[xyster]

Thanks guys. I did drill a ~1/4" hole through the brush holder plate as a continuance of the main inlet. That hole is shown in the pic below. The inlet through the cover is 5/8". May not provide much flow, but it looks as if some air will blow directly onto the windings as they rotate by. There's also room for air holes above the gearbox on the backside.
At this point, I'm leery of extracting the rotor because I have no idea how hard it'll be to fit back into its bearing, or if the bearing would come with the rotor, or what problems I might encounter. I'm trying to make this a progressive project -- just going far enough to keep the motor cool enough to keep my hand on no matter how hard I run it at 32 volt 35 amps. I'm not planning to over-volt it any more than that...famous last words, perhaps.

 

[fechter]

It should be easy to extract and replace the rotor. The brushes are the tricky part.

Any air flow is better than none, but to get maximum effect, you need the equivalent of a 7/8" hole.

What blower are you planning to use?

 

[xyster]

It should be easy to extract and replace the rotor. The brushes are the tricky part.

Thanks Fechter, that's good to know. If this mod doesn't completely do the job, then I'll plan on opening a 7/8" outlet hole on the backside, and plugging the other small holes on the cover to force the air over the windings.

What blower are you planning to use?

Don't know -- any ol' 24vdc brushless blower should work ok, right? I've already wired a 24v tap to the SLA's for powering accessories.
How's this one look?
http://www.allelectronics.com/cgi-bin/item/CF-229/220300/24_VDC,_5%22#34;_BLOWER_.html

 

[fechter]

What blower are you planning to use?

Don't know -- any ol' 24vdc brushless blower should work ok, right? I've already wired a 24v tap to the SLA's for powering accessories.
How's this one look?
http://www.allelectronics.com/cgi-bin/item/CF-229/220300/24_VDC,_5%22#34;_BLOWER_.html

That one looks good. Pretty much any centrifugal type blower will work. 10w should be a good size.

 

[TylerDurden]

At this point, I'm leery of extracting the rotor because I have no idea how hard it'll be to fit back into its bearing, or if the bearing would come with the rotor, or what problems I might encounter.

Fear not.

There is only a single sealed bearing behind the rotor. If it comes out with the rotor, you can just pop it back in.

You could probably put six 1/2" holes in the back plate without any problems.

(Even the grease in this thing stinks)

 

[D-Man]

On the Currie bike's, it seems that no one has mentioned yet how well they climb. (24 volts vs 36 volts) Someone needs to measure some grades so we know exactly how much its really capable of. Maybe xyster, the expert tester can do it. Or Knightmb, but he's always pedaling.

 

[TylerDurden]

I wouldn't recommend drilling between the magnets since the metal there is needed to carry the magnetic flux.

Yep.

I thought the case was just aluminum...

But on close inspection, I found that a steel ring holds the neo-magnets and the aluminum case is actually cast around the ring. There was flashing from aluminum seeping at the edges.

I tested the metals using a rotary tool... yellow sparks when grinding the steel ring. (The magnets actually sucked the bit out of the tool a couple of times...)

I suppose if you got ambitious, you could actually grind/cut deeper fins into the alum portion of the case to increase the surface area for cooling.

Mathurin?

:lol:

 

[xyster]

On the Currie bike's, it seems that no one has mentioned yet how well they climb. (24 volts vs 36 volts) Someone needs to measure some grades so we know exactly how much its really capable of. Maybe xyster, the expert tester can do it. Or Knightmb, but he's always pedaling.

Well, it does great on a 5% grade if that's any help.
At 32V the motor starts getting awfully hot up anything much steeper, so I want to cool it better before testing it more. Seems to me, up until the motor melts, it'll perform as well as any other single-gear system fed 1000 watts -- 'bout 10mph up a 15% grade says the calculator.
http://www.kreuzotter.de/english/espeed.htm

Rotor removal question:
Isn't the axle, passed through to the gear box, part of the rotor? I'm assuming a gear is attached on the end, which I'm concerned might just pop off if I pull the rotor, and be difficult to get back on again.

 

[TylerDurden]

Isn't the axle, passed through to the gear box, part of the rotor?

The rotor shaft has splines that engage the large reduction gear.

It pulls right out and goes right back in.

Ain't luv grand??


8)

 

[xyster]

It pulls right out and goes right back in.

Ain't luv grand??

Yah, uhmmm....not quite what I had in mind when I said I loved my bike. But hey, whatever floats your boat.

All the same, many thank-you's for the pornshot and libidinous description, TylerDurden.

 

[Mathurin]

Actually I've thought of something in similar lines: How much lighter can an MY1018 be made to be?

I figure a stock MY1018, crank mounted on a fairly light bike and used with a backpack battery shouldn't cripple it too much. Though, I don't like the idea of mounting that much weight at either end of the bike, I mean it's heavier then a 2l pop bottle... Ouch!

Anyways, drilling tons of holes in the covers ought to reduce the weight a bit...

 

[TylerDurden]

All the same, many thank-you's for the pornshot and libidinous description, TylerDurden.

No problemo. Just tryin to fill-in for the AWOL Reido. (?) He is the king of MY1018 cooling.

:?

 

[Anonymous]

Hi everyone. Justed signed up as I've been really getting into ebikes lately and currently looking at trying to put one together. Xyster, any chance of finding out how many teeth are on the large cog that's connected to the hub? I'm thinking of a similar design, but I need more speed.

 

[Toorbough ULL-Zeveigh]

Wlecome aboard.
Austraya seems to be well represented here, almost par with Murrikins.
I wonder why it's so, expensive guzzle-lean I take it.

Is '#946;#949;' an aboriginal name, denoted with a double clicking sound?

 

[Ben]

Hahaha, no. Tried to write my name with beta, epsilon and eta, but didn't work, so I guess I'm stuck with just plain old Ben.