Back In A Currie: 06 Mongoose Review

[xyster]

Hello. Long time no see Hope nobody got run-over, suffered serious drain bamage or anything...

I just purchased an '06 24V 35A Mongoose through Currie's new Amazon site. The bike arrived in the allotted time, and in good apparent condition, except for a broken battery box plug receptacle -- which a little super glue cured quickly. The (2) 12ah SLA's came charged to only 24V. I'm hoping no permanent damage's been done them.

Unpacking and assembly took about an hour. The maiden voyage around the neighborhood was great, except for a rattling/grinding sound from the rear, but only on hard left turns (any ideas? I'm hoping it's not something in the already over-amped 250W motor's gearbox). The controller, ostensibly rated at 35 amps, sits in a supporting triangle below the battery box. As I expected, power and speed is somewhat underwhelming compared to my other ebike. But for $300 USD, I'm mostly pleased so far.

Not pleased with the range. I only got 8 miles on the level, no wind and no pedal, WOT @ ~15mph, and with 12 stop/starts. I've read somewhere here a similar Currie getting 11 or 12 miles (wasn't that your review, knightmb?). Anyway, I hope the disappointing range is a function of new SLA's, and not sulfated SLA's. I'd planned to parallel two 10ah SLAs from my scooter anyways, so because of the poor range I went ahead and did that today. As seen in the last pic, two 10ah SLAs just barely fit end-to-end upright in the triangle -- I had to sand one edge of the top battery.

Later, I'll probably replace the SLA's with something better, maybe do the overvolt/forced-air cooling routine. But I've already got one hot rod, and I don't want to overdo the mods since this is supposed to be my "won't freak if it gets stolen" bike that I can leave locked but unattended in public places. It's also supposed to be the girlfriend's ride for when we're out together -- for some silly reason my other ebike scares her. My mod options are pretty limited anyway since she's banned me from putting duct tape anywhere on this new bike (note the duct tape only on the scooter's batteries now on the ebike ) .

[Toorbough ULL-Zeveigh]

It's great to have you back. (yay!)
Your timely arrival has in all likelyhood kept me from heading out the door.
Like a streak of light, he arrives just in time! (Spiderman,Spiderman...)

I too hate the fact having a very nice ebike that I can't leave anywhere which is why I'm leaning towards getting an I-Zip.
The Mongoose looks very similar to the Schwinn I-Zip that Canadian Tire is selling which I've posted about, but that may just because of the Currie. With the Canadian dollar approaching parity with the U$ in preparation for unifying the currency, I'll probably pick one up, especially if they have an end of the season blowout. So I'll be following any your mods with particular interest.

I've been checking on & off at CTC & they said that they're having difficulty keeping stock. Which isn't saying much because they probably grossly underestimated the demand to be on the safe side. But just goes to show that a low cost option like this people are willing to take a chance & that there is a market out there for people like your girlfriend who aren't speed obsessed.

The batteries you've added look right at home there & an absolute necessity sounds like. If the stock range your getting is normal, I think that will disappoint most people. But once they get a taste the seed will have taken root in some & then start down the road of upgrades beginning with the battery. It's like a crack addiction, the first sample comes cheap & once your hooked your mortgaging your house.

[knightmb]

Not pleased with the range. I only got 8 miles on the level, no wind and no pedal, WOT @ ~15mph, and with 12 stop/starts. I've read somewhere here a similar Currie getting 11 or 12 miles (wasn't that your review, knightmb?). Anyway, I hope the disappointing range is a function of new SLA's, and not sulfated SLA's. I'd planned to parallel two 10ah SLAs from my scooter anyways, so because of the poor range I went ahead and did that today. As seen in the last pic, two 10ah SLAs just barely fit end-to-end upright in the triangle -- I had to sand one edge of the top battery.

Yes, if you add another 12 @ 12AH SLA (36 volts), it will increase the range to 18 miles and the top speed to 30 MPH on level ground, no wind, etc. Real speeds given real world conditions you hit about 28 MPH tops.

Later, I'll probably replace the SLA's with something better, maybe do the overvolt/forced-air cooling routine. But I've already got one hot rod, and I don't want to overdo the mods since this is supposed to be my "won't freak if it gets stolen" bike that I can leave locked but unattended in public places. It's also supposed to be the girlfriend's ride for when we're out together -- for some silly reason my other ebike scares her. My mod options are pretty limited anyway since she's banned me from putting duct tape anywhere on this new bike (note the duct tape only on the scooter's batteries now on the ebike ) .

That's exactly how I use mine, trips to the store, etc. The wife rides it from time to time for fun. On the air cooling, ours is still stock motor, no mods on it so far. The 36 volts does warm it up, especially with some of the hills around here. I put a temperature sensory on it during some testing, the motor gets hot, too hot for me to tough, but according to the sensor it's never really over 130 F that often. Which is hot enough to burn human skin, but hasn't been hot enough to melt the inside. I pull the motor apart every now and then to see if the inside has bitten the dust, but so far it has surprised me by "living" this long. I was going to go hub motor once this motor died, but it keeps living for some reason, Believe me when I say I'm not nice to it, I go full power around everywhere.

[fechter]

We were about to call the RCMP to go looking for you. Hope you had a good vacation. Now you have to read 400 posts to catch up.

Does the bike hub have freewheels on both sides?

Do you know if the motor has rare earth magnets?

[knightmb]

Does the bike hub have freewheels on both sides?

I can answer that one
Yes, as far as I can tell it does. If you stop the motor, the chain stops but the wheel keeps rolling. If you pedal with the gears, same effect. If you roll the bike backwards, both sides roll backwards with the wheel, gears and motor.

[xyster]

Ahhh...much better performance today with the 10ah SLA's in parallel. Before, under full load the low battery indicator came on after just a couple miles, and the bike's response became sluggish. I'll do some tests later. Taped to the seatpost (my girlfriend mercifully reinstated my duct tape privileges) the two extra SLA's don't feel like they added much weight either.

It's great to have you back. (yay!)
Your timely arrival has in all likelyhood kept me from heading out the door.
Like a streak of light, he arrives just in time! (Spiderman,Spiderman...)

I too hate the fact having a very nice ebike that I can't leave anywhere which is why I'm leaning towards getting an I-Zip.

Hey Turbo -- that's very nice of you to say, and I just saw Spidey 3 the other day If I recall, the Mongoose line is being dropped in favor of the iZip line. Do you know if those are produced by different manufacturers?

Yes, if you add another 12 @ 12AH SLA (36 volts), it will increase the range to 18 miles and the top speed to 30 MPH on level ground, no wind, etc. Real speeds given real world conditions you hit about 28 MPH tops.

I don't see how range will increase since with this under-powered puppy, we'll be using that extra power most of the time. After I put the fourth SLA in my Currie Stealth, practical range stayed about the same -- I could go WOT 10 miles at 24mph instead of WOT 10 miles at 18mph. Now if this bike started with better power, opening up the throttle would be more of an occasional thing like it is for my other ebike.

On the air cooling, ours is still stock motor, no mods on it so far. The 36 volts does warm it up, especially with some of the hills around here. I put a temperature sensory on it during some testing, the motor gets hot, too hot for me to tough, but according to the sensor it's never really over 130 F that often. Which is hot enough to burn human skin, but hasn't been hot enough to melt the inside.

That's very good to know. I seem to remember Reid writing that at 36 volts his same motor died after only 7 miles at top speed. Which is why he went FAC on the next. Perhaps the motor would run much cooler with simply a little passive ventilation. I'm thinking two PVC elbow joints, one pointed forward for wind in-flow, one pointed backward for outflow might provide sufficient temperature headroom while also blowing out the brush dust. Have you opened the motor yet? I'm wondering if it's one of those motors with tricky-to-reseat brushes.

We were about to call the RCMP to go looking for you. Hope you had a good vacation. Now you have to read 400 posts to catch up.

Does the bike hub have freewheels on both sides?

Do you know if the motor has rare earth magnets?

RCMP? Is Canada poised to stage a socialist takeover of the United States or something ?

With it's freewheel, this bike is much easier to pedal than my 100+lb X5, and coasts much better than my brushed-but-no-freewheel scooter. I don't know the type of magnet. With its offset axle, the motor looks to have an internal gear box of some sort. Anybody know anything about that? Or any possible bolt-on replacement motors?

[knightmb]

The maiden voyage around the neighborhood was great, except for a rattling/grinding sound from the rear, but only on hard left turns (any ideas? I'm hoping it's not something in the already over-amped 250W motor's gearbox).

I forgot to answer this part, that rattling from the rear is the kickstand I found out when my wife riding it and noticed the same sound when she hit any major bumps.

[xyster]

On the assumption 8 volts would increase the performance of a 24 volt bike much more than decrease the performance of an 80 volt bike, today I moved a box of 2s15p lithium 18650s (33ah 8volts) from my x5 to my Currie.

What a difference! I don't have instruments on the Currie yet, but now it feels almost as peppy as my 48 volt 30 amp scooter, with about the same 24 mph top speed.

Now, *sob* I must find a way to get by with only 72 volts on the x5. Fortunately, that little 8 volt box is easy to disconnect and move, so I may just switch it back and forth between the bikes.

Here's the basic ~32volt 22ah configuration:

[TylerDurden]

Do you know if the motor has rare earth magnets?

The unite 250W geared have neo magnets.

[Beagle123]

Hey, you're not supposed to be riding anything that looks that cool. I thought you only rode things that look like a hefty bag.

[xyster]

Hey, you're not supposed to be riding anything that looks that cool. I thought you only rode things that look like a hefty bag.

Worry not my young apprentice, my rep shall remain intact, for with typical dedication I've been busy crapping up the bike with extra battery boxes, gadgets, duct tape and such. I'll post another pic after it's fully ugly-ified.

[sabrewalt]

Wow What a great report. I bought that same mongoose for a backup. Nice to know we can pep it up a bit. Been using mine to get from way out cheap parking to the football games at my son's college.



Keester wrote..
SNIP
What a difference! I don't have instruments on the Currie yet, but now it feels almost as peppy as my 48 volt 30 amp scooter, with about the same 24 mph top speed.
SNIP

[xyster]

For $300, it's a great entry level ebike, and pepping it up to 32-36 volts (1000 watts) makes for a very respectable 20-25mph commuter.

[xyster]

Here's a pic of my recent mods....
The passive ventilation holes seem to help keep the motor a little cooler. At 32 volts, just cool enough after a pretty hard ride to keep my hand on indefinitely. Hopefully the little motor will live a nice long life. When the brushes go, I'll probably replace the whole motor with a cheap, brushed Crystalyte hubmotor since I could use the same, stock controller.
Most of the rest of the added stuff I stole from my scooter, or had laying around the garage

[fechter]

I see the silver duct tape matches the frame

Bigger holes would help the cooling, so would a blower. If it's not overheating, then you don't need to worry about it.

[xyster]

I see the silver duct tape matches the frame

Duct tape is the poor man's metallurgy.

Bigger holes would help the cooling, so would a blower. If it's not overheating, then you don't need to worry about it.

Hoping it'd be good enough, I kept the holes small so that rain and splash wouldn't have easy ingress.

Fechmaster, I'd like to check my assumptions in re approximate safe motor temperature and estimation:

If I can hold my hand on it, is that likely cool enough?

And if I can't, is that likely hot enough to permanently fry something inside?

Is the motor damage caused by overheating a digital thing -- either it's fried, or it's not? Or can operation in a range between "fried" and "cool" cause slowly accruing damage too?

[fechter]

If you can hold your hand to it, then the magnets should stay happy. If you overheat the magnets, they can lose all or some of their strength. This type of failure may be partial. Most rare-earth magnets are good to at least 80C. Some are good to 100C or more. If you can sizzle spit on the motor housing, the magnets will probably be unhappy.

If the windings fry, they usually short out, creating lots of stinky smoke. This case will be obvious and the motor will be dead.

It's hard to judge the armature temperature from the outside case temp, but if it never gets too hot to touch, you should be in the safe operating zone.

[Beagle123]

I see the silver duct tape matches the frame

Duct tape is the poor man's metallurgy.

Whew, xter. I'm glad to see that you solved the "cool" problem on that bike. You did a great job uglifying your bike. Your girlfriend can rest easy knowing that you're not out picking up on women.

If you'll allow me to make a suggestion, I'd suggest covering the remaining areas that aren't covered in duct tape with more duct tape. You could make it look like something you'd see on the show "lost in space."

Personally, I've taken a different approach: My bike <a href="http://endless-sphere.com/forums/viewto ... ">LOOKS</a> cool, but it will only go about 15mph right now. Last time I rode by a Burger King, a bunch of kids were laughing at me.

Sometimes it's hard to be ahead of your time.


P.S. They also sell this tape called "Gorilla Tape" which is similar to duct tape, and waterproof, strong etc. However, it is black. If you ever feel the need to build black into your color scheme, you might consider it. It holds my batteries together.

[xyster]

Whew, xter. I'm glad to see that you solved the "cool" problem on that bike. You did a great job uglifying your bike. Your girlfriend can rest easy knowing that you're not out picking up on women.

And quite a problem it was. Before the tape, I used to be ogled by hot chicks a dozen times a ride. Now, I can pedal without feeling like I'm in some female breeding-stock surveillance program. Though worth it, one woman is plenty hard enough to deal with. The equation tips the other way with more than one (unless they're twins or genetic clones -- that's ok.)
I also worry less about the bike being stolen, or its steel parts rusting -- which with duct tape in place is twice as unlikely now because the bike is mostly aluminum.

If you'll allow me to make a suggestion, I'd suggest covering the remaining areas that aren't covered in duct tape with more duct tape. You could make it look like something you'd see on the show "lost in space."

I'll have to perform some fancy calculus to find the area of tape necessary, multiplying tape area X tape density to derive Total Tape Weight. For best handling, I prefer a TTW of less than 10lbs -- but that's just me. Others may prefer a higher or lower TTW.

Personally, I've taken a different approach: My bike LOOKS cool, but it will only go about 15mph right now. Last time I rode by a Burger King, a bunch of kids were laughing at me.

From the looks of that moped, I surmise you've solved your chick-ring surveillance problem too. I take bikes and crap them up. You take crappy bikes and keep them crappy. What a stroke of genius, my friend! The real lazy-man's method to anonymity via obscurity.

Sometimes it's hard to be ahead of your time.

Tell me about it! On those preference-selection documents we all sign before birth, I checked: Male; circa year 2,571; Planet Earth. Some jerk in the Incipient Consciousness Office really screwed up by sending me to 1971. I hear it's worse though when the angel bureaucrats upstairs mis-assign gender or destination -- so I'm counting my blessings and just dealing with it. Next time though, I expect better service. Perhaps before I die I should prepare a bribe to be bundled with me in my casket. Sounds like many others on this planet also got the cosmic shaft.

P.S. They also sell this tape called "Gorilla Tape" which is similar to duct tape, and waterproof, strong etc. However, it is black. If you ever feel the need to build black into your color scheme, you might consider it. It holds my batteries together.

Thanks for the tip. My girlfriend's partial to green. Seen any green duct tape?

[Beagle123]

From the looks of that moped, I surmise you've solved your chick-ring surveillance problem too. I take bikes and crap them up. You take crappy bikes and keep them crappy. What a stroke of genius, my friend! The real lazy-man's method to anonymity via obscurity.

All I want out of life is to be anonomous.

I'm glad to see you've gotten all those women under control, and i will keep a lookout for green duct tape.

Also, I saw this motor that looks like it would fit your bike:

<img src="http://us.st11.yimg.com/us.st.yimg.com/ ... 947_156916">

http://www.thesuperkids.com/10wabrmofors.html

You could put duct tape over the nice looking logo.

I noticed that you upgraded your batteries. I'm sure your controller is next. Then your motor will blow up. Perfect excuse to get this one! 1000 watts.

[xyster]

That's the motor on my Schwinn s1000 scooter! It is a very good motor, capable of 2500 watts continuous with a little forced-air cooling. I ran it at 48 volts 80 amps for awhile last summer.

I haven't taken a good look, but to get it to fit my currie bike I'd have to do some serious motor-mount mods. Might be worth a try, though. The one on my scooter is married to the currie direct-drive unit, so I'd have to remove that.

Taking the motor off my scooter would seriously degrade its performance. But I could save my pennies and buy that one....

Thanks for the tip.

[kisshu]

wow i'm glad to meet you ... i just returned one to the store. did i do the wrong thing?

you mention the motor being 250 watts i thought it was a 450 watt motor?

also if the motor dies why not switch to a 600 bmc watt or higher instead of a hub motor?

now the important stuff.... modifications

i live on a long hill about 1 mile with various grades 10 to 25 maybe and want to be able to travel to the next town over and back about 7 miles each way the trip from the botom has a lot flat road and some 1 to 5 degree grades.

i too found i could only go a short distance before the batteries indicated red etc. right now i would only be able to go to the store at the botom of the hill - about two miles and back with pedaling before it runs low - and the power is not great for climing the hill i live on.

is it a good bike for modification so i could make the 15 mile round trip and beable to do 20 - 25 some times? its way too slow and powerless

also, ive been looking into other setups like a crank drive set up to take advantage of gearing

why not put the motor where the controller sits and run it off the crank with free wheel? i noticed everything it welded - the controller and kick stand - how feesable is this for modification like using a cyclone system
or other type crank driven system? given the kickstand would have to be removed with a torch etc.

or can i get away with converting it to a higher voltage with same motor or using a higher watt motor? i really would like to use the gearing though
is it worth the bike frame price wise and weight or is it better to find a lighter used frame?

its really unusable without modification and you have given me some hope

i really appreciate your expertise and advice
let me know what you recommend please

also i weigh about 180 lbs

thanks alot xyster !!!!

[xyster]

wow i'm glad to meet you ... i just returned one to the store. did i do the wrong thing?

Nice to meet you too. I don't know if you did the wrong thing...let's talk about it.

you mention the motor being 250 watts i thought it was a 450 watt motor?

Motor ratings are very open to interpretation. Basically the rating should be the maximal amount of input power that the motor can handle continuously without being damaged. This motor is rated by its manufacturer for 250w (I forget the website, we've discussed it another thread here). Currie is already feeding it about 840 watts max (24 volts X 35 amps -- the controller is a 35 amp controller). So I don't know where Currie gets their 450 watt rating. Anyway, without extra cooling, the motor will handle 1,260 watts (36 volts through the stock 35 amp controller) for short bursts of a couple miles. Another member ruined his same currie motor running it at 36 volts 35 amps -- he reported the motor died after 7 miles going 26 mph.

also if the motor dies why not switch to a 600 bmc watt or higher instead of a hub motor?

Correct me if I'm wrong, I think the BMC is a brushless motor, and so would require a new controller. I have a high-power brushless ebike already. This is supposed to be my cheapo that I can leave in public places and still be able to replace if it gets stolen. Brushed hubmotors are cheap too, or I could bolt-on something like that $169 1000 watt motor we were just discussing...

now the important stuff.... modifications

i live on a long hill about 1 mile with various grades 10 to 25 maybe and want to be able to travel to the next town over and back about 7 miles each way the trip from the botom has a lot flat road and some 1 to 5 degree grades.

i too found i could only go a short distance before the batteries indicated red etc. right now i would only be able to go to the store at the botom of the hill - about two miles and back with pedaling before it runs low - and the power is not great for climing the hill i live on.

is it a good bike for modification so i could make the 15 mile round trip and beable to do 20 - 25 some times? its way to slow and powerless

The bike really perks up with an extra 8-12 volts. The simply way to get 15 miles sometimes going 20-25 mph would be to wire in series a third 12v 12ah SLA battery (just like the two it comes with). Check the motor and don't let it get so hot you can't hold your hand on it. If you don't want to worry so much about the little motor burning up, do the "forced air cooling" modification that's detailed elsewhere here. You'd also need a second charger (a 12 volt SLA charger) to charge the third battery, or a 36 volt SLA charger, rewiring the charging system to charge all three at once.
Alternatively, you could wire in parallel two extra SLAs (total of 4), keeping the whole system 24 volts. Your range will more than double to at least 20 miles as you describe the terrain, the bike will perform a little better because of less voltage sag (the red light won't go on after only a couple miles), you won't need to do anything different to charge the extra batteries, and the motor shouldn't ever fry, but you won't be able go 20 mph without pedaling really hard.
I did a combination of the two mods, first wiring in parallel two more 12v SLAs, then wiring that in series to 8 volts of extra lithium batteries from my other ebike.

also, ive been looking into other setups like a crank drive set up to take advantage of gearing

why not put the motor where the controller sits and run it off the crank with free wheel?

If you've got metal fabrication skills and equipment, or have a friend who does, sure...you could do almost anything you wanted.

i noticed everything it welded - the controller and kick stand - how feesable is this for modification like using a cyclone system
or other type crank driven system? given the kickstand would have to be removed with a torch etc.

Seems to me if you wanted to go with the cyclone, you might as well put it on a regular bicycle. What would be the advantage to tearing this Currie down in order to make it a Cyclone system?

or can i get away with converting it to a higher voltage with same motor or using a higher watt motor? i really would like to use the gearing though
is it worth the bike frame or is it better to find a lighter used frame?

I'd get a different frame. Jondoh here has a nice review of a cyclone system:
http://endless-sphere.com/forums/viewto ... ht=cyclone

its really unusable without modification and you have given me some hope

i really appreciate your expertise and advice
let me know what you recommend

also i weigh about 180 lbs

thanks alot xyster !!!!

Glad I could help. I think this is a terrific bike for the money, and after a couple battery additions, (total cost bike + mods about $400), achieves a very respectable 20-25mph for 20-25 miles. Motor temp must be monitored regularly, especially after riding up hills or at speeds more than 20mph for more than a few miles, else a cooling blower mod is in order (another $20 or so).

If you have more than $800 dollars to spend, I'd choose something else.

[Instant Karma]

I believe those cheapo brushed motors Currie is using is like 250 watts
continuous and maybe 450 for a very very short time or they'll go up in
smoke. evdeals.com has all kinds of different sprockets combinations for hill use or flat use to maximize efficiency as much as possible and also upgrades to 48V BMC with ext. controller which is pushing 1000watts power. I would like to know if the newer Curries are compatible with the old setups but I doubt it, knowing Currie they would
deliberately make it tougher for anybody to modify it with the older setups that apparently worked a lot better than the new ones.

[kisshu]

so what your sayng is the 450 watt motor is really a crappy 2-250 watt motor and if i upgrade the motor and batteries i could get a lot more performance without having to go to a crank drive system.

what kind of performace increases could i expect from upgrading my bike motor (using the batterie upgrade youve done on yours) to an actual 450 watt motor a 600, 750 and 1000 watt motor in each case? and what would the controller upgrade cost?

what sproket changes would you do if any?

and since for a larger motor you would do a controller change as well is there any advantage of using BL vs brushed motor set up ?

how does a hubed motor compare with the electro drive are there any advantages one over the other?

and whats the currie prodrive, uspd? verses the electro drive system - is one esier to modify and upgrade over the other? i'm still confused about that issue.

i asked currie why they didn't use brushless motors and they said they used to but don't anymore because the brushless motors had the controller built in and it was harder to maintain if the controller blows - on the brushed the controller is seperate and easy to replace.

but i see mostly bL motors in 600 watts and above - i thought bL motors were better because they could handel wider voltage and watt range???

is currie just being cheap?


{you mentioned what would be the use in tearing down the currie.}
i thought since the gb24v 450 is designed for ev use the frame must be more suitable than getting some other cheap bike - maybe the extra heft is more reliable.
is it possible to buy an ev bike frame for less and build your own than buying the mongoose complete and modifying it? i guess that was what i was getting at?

i would like to beable to get 1.5 hp that would be great!

any more than 2 to 3 hundred dollars i would rather go big and get something that could run a briggs and straton etc. - 15 hp is very tempting for the price of some expensive geared hub motors!
are there any motors inbetween like 3-7 hp but 3 - 4 hundred dollars?

thanx alot guys for your help!